tag:theconversation.com,2011:/africa/topics/aircraft-safety-33778/articles
Aircraft safety – The Conversation
2024-03-08T11:34:27Z
tag:theconversation.com,2011:article/225292
2024-03-08T11:34:27Z
2024-03-08T11:34:27Z
Flight MH370 is still missing after ten years – forensic experts explain what we know and why we haven’t found the plane
<p>It has been ten years since Malaysian airlines flight MH370, carrying 239 passengers and crew on board, disappeared less than one hour after taking off from Kuala Lumpur on 8 March 2014. It has become one of the great unsolved mysteries of modern times and is a puzzle that has remained resolutely unsolved. </p>
<p>Theories abound on the flight’s disappearance and current location of the wreckage. Unusually, all communications aboard the plane were switched off shortly after take-off. </p>
<p>Intermittent satellite location information subsequently suggested <a href="https://slate.com/technology/2014/06/inmarsat-releases-data-showing-mh370-definitely-went-south.html">it was flown south on a very different flight path</a> than expected, to a remote and deep ocean area of the Southern Indian Ocean before contact was lost.</p>
<p>When actively searching for MH370, sophisticated international surveillance aircraft initially conducted over 300 flights to visually look for plane debris on the surface. Then surface and submersible vehicles conducted further surveys, searching over 120,000 sq km of ocean before ending the search in 2017. </p>
<p>The effort to find MH370 became one of the <a href="https://www.telegraph.co.uk/news/worldnews/asia/malaysia/10863605/MH370-search-becomes-most-expensive-aviation-hunt-in-history-yet-still-no-clues.html">most expensive aviation searches in history</a>. These surveys used both <a href="https://en.wikipedia.org/wiki/Sonar">sonar</a> (active acoustic instruments to image the sea floor to locate the aircraft), and also listening devices to pick up the aircraft’s <a href="https://en.wikipedia.org/wiki/Flight_recorder">flight data recorder</a>. </p>
<p>Confirmed MH370 plane debris were found on Reunion Island in July 2015, and off the coast of Mozambique in February 2016, which was consistent with what we know about ocean currents. In 2018, OceanInfinity, a private exploration company, <a href="https://oceaninfinity.com/ocean-infinity-to-continue-search-for-missing-malaysian-airlines-flight-mh370/">also searched 25,000 sq km</a> but without success.</p>
<p>Since then, a mixture of highly trained experts and members of the public have sought to assist the <a href="https://www.mh370search.com/">search</a>. These efforts have varied from simple to really advanced data analysis. They have attempted to map the locations and timings of plane debris, and other maritime debris, as well as model drift currents. In doing so, they are attempting to reconstruct where these may have originated from, which is no small task. </p>
<p>Analysis of the MH370 flight path has been pieced together from two different types of radar – primary and secondary – as well as the intermittent data “pings” from the plane to the <a href="https://en.wikipedia.org/wiki/Inmarsat">Inmarsat</a> satellite. The results suggest that it <a href="https://www.bbc.co.uk/news/science-environment-27870467">diverted south from its intended flight path</a>.</p>
<p>Another technique called weak signal propagation (<a href="https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software)">WSPR</a> data (a way of using radio emission to track objects such as planes), had defined a specific but very large search area, some of which has already been searched.</p>
<p>Available hydroacoustic data (based on the way sound propagates in water) of the sea floor has also been analysed. However, only a relatively small area was covered and the marine sea floor in this region can be very rugged. There are deep <a href="https://www.sciencedirect.com/science/article/pii/S007966112200163X">submarine canyons</a> that can hide objects much bigger than a plane. </p>
<p>Lessons from studying past flight disasters also informed the search. These included the 2009 Yemenia plane crash in the Indian Ocean.</p>
<h2>Recovery operation</h2>
<p>For inland or coastal water searches, a phased investigation strategy is suggested as <a href="http://dx.doi.org/10.1016/j.earscirev.2017.04.012">best practice</a>, where investigators look to identify water depths, major current strengths and directions, together with pre-existing site information, before specialist search teams are employed using methods, equipment configurations and personnel that have all been accredited.</p>
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Read more:
<a href="https://theconversation.com/how-science-is-helping-the-police-search-for-bodies-in-water-73931">How science is helping the police search for bodies in water</a>
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<p>However this reliance on technology can be problematic. Even in small waterways, the presence of vegetation in the search area or a target buried by sediment can make these searches difficult.</p>
<p>Much of the Southern Indian Ocean sea floor is rugged and relatively unmapped, with <a href="https://www.bgs.ac.uk/news/deepest-points-of-the-indian-ocean-and-southern-ocean-revealed/">water depths of up to 7.4km</a>. It’s away from regular shipping lanes and commercial flight patterns, with few fishing boats, no significant land masses and some of the worst winds and weather in the world. These factors also make it a very challenging area to search. </p>
<p>In deep water (more than 2km to 3km) deploying sonar is cumbersome and prohibitively expensive. It also takes a long time to generate data. A major challenge for scanning technologies is achieving accuracy at these kinds of depths due to the scattering of the signal caused by uneven, especially rocky substrates on the sea floor.</p>
<p>The development of more advanced autonomous submersible vehicles may hold the
key to finding MH370 in the Southern Indian Ocean, along with post-processing of
raw data which can clarify what can be attributed to rocks as well as sea-floor
hummocks and pockets. </p>
<p>This can distinguish between the sea floor and the objects being searched for. However, the area where MH370 disappeared is vast, meaning future searches will remain just as challenging as when the plane first went missing in 2014.</p><img src="https://counter.theconversation.com/content/225292/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jamie Pringle receives funding from the HLF, the Nuffield Foundation, Royal Society, NERC, EPSRC and EU Horizon2020. He is affiliated with the Geological Society of London. Jamie works for Keele University.</span></em></p><p class="fine-print"><em><span>Alastair Ruffell receives funding from: ProjectBoost (IntertradeIreland); Arts & Humanities Research Council; Natural Environment Research Council; Engineering & Physical Sciences Research Council.</span></em></p><p class="fine-print"><em><span>Ruth Morgan has received funding from the UK Arts and Humanities Research Council and the UK Engineering and Physical Sciences Research Council.</span></em></p>
Despite advanced technology and search techniques the rugged seafloor can hide objects much larger than a plane.
Jamie Pringle, Reader in Forensic Geoscience, Keele University
Alastair Ruffell, Reader, School of Natural and Built Environment, Queen's University Belfast
Ruth Morgan, Vice Dean Engineering (Interdisciplinarity Entrepreneurship), Professor of Crime and Forensic Science, UCL
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/221069
2024-01-19T13:41:11Z
2024-01-19T13:41:11Z
Boeing door plug blowout highlights a possible crisis of competence − an aircraft safety expert explains
<figure><img src="https://images.theconversation.com/files/569659/original/file-20240116-21-w7tewc.jpg?ixlib=rb-1.1.0&rect=24%2C24%2C5439%2C3612&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An investigator examines the frame of a Boeing aircraft whose door plug blew out in flight.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/BoeingEmergencyLanding/390bb7248d0f4069b1b987492afbc254/photo">National Transportation Safety Board via AP</a></span></figcaption></figure><p><em>In the wake of the <a href="https://www.cnn.com/2024/01/08/us/what-happened-alaska-airlines-flight-1282/index.html">in-flight blowout of the side of a Boeing 737 Max 9</a>, federal regulators have grounded planes and are stepping up scrutiny of Boeing’s manufacturing process.</em></p>
<p><em>The Jan. 5, 2024, explosive decompression after takeoff was related to a component called a “door plug” being ejected from the fuselage of the aircraft. This was after <a href="https://apnews.com/article/alaska-airlines-portland-oregon-emergency-landing-aab8ee1e594369ab48fa3ce60f3acdc6">three prior flights of that plane</a> had registered warning signals about cabin pressurization. The National Transportation Safety Board is investigating that incident.</em></p>
<p><em>In addition, the Federal Aviation Administration has launched an investigation into Boeing’s manufacturing process. Other incidents have raised concerns about other 737 Max aircraft – not just <a href="https://theconversation.com/heres-how-airplane-crash-investigations-work-according-to-an-aviation-safety-expert-113602">fatal crashes in 2018 and 2019</a>, but more recent examples of <a href="https://www.bbc.com/news/world-us-canada-67919436">bolts or other fittings or fasteners</a> not being up to standards.</em></p>
<p><em>The Conversation U.S. asked <a href="https://scholar.google.com/citations?user=I0IMxAkAAAAJ&hl=en&oi=ao">Daniel Kwasi Adjekum</a>, an aviation safety expert and professor of aviation at the University of North Dakota, to explain the significance of the incident, the government’s response and what it all means for the flying public.</em></p>
<h2>Why is Boeing – not the airline – responsible for the door plug being secure?</h2>
<p>Under U.S. federal requirements, the number of occupants in an aircraft and the seating arrangements determine the <a href="https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-25/subpart-D/subject-group-ECFR88992669bab3b52/section-25.807">number and placements of emergency exit doors</a>. Airplane manufacturers build fuselages with enough openings to accommodate all the doors that might be needed. If airlines choose to use the highest-density seating arrangements, they need to use all of the openings for actual exit doors. But not all airlines pack the seats in that tightly; on those planes, some emergency doors are not needed. Those spaces are filled by door plugs.</p>
<p>In the case of the Boeing 737 Max 9 aircraft, the door plugs are fitted by Spirit AeroSystems in Wichita, Kansas, which is the supplier of the airframe to Boeing. The final assembly of the aircraft is carried out at the Boeing plant in Renton, Washington. Quality control checks are done at Spirit AeroSystems, and then another round of quality checks is done by Boeing. These include a high-pressure test to ensure that the cabin can be pressurized safely and to ensure the integrity of the fuselage and pressure bulkheads.</p>
<p>Normally, the plugs are not removed during those tests at the Boeing facility, though they are checked to ensure they are correctly aligned with the rest of the fuselage. Overall, it is Boeing’s responsibility, as the original equipment manufacturer, to ensure the components conform to the FAA’s design, manufacturing, installation and performance requirements. </p>
<h2>Do the airlines have any reason to inspect the bolts that fasten the plugs in place?</h2>
<p>Under normal circumstances, once they are delivered and initially inspected, door plugs and their components are not adjusted by the airline maintenance team, though their integrity is checked as part of stipulated maintenance checks. Records from Alaska Airlines suggest that on previous flights before this incident, <a href="https://apnews.com/article/alaska-airlines-portland-oregon-emergency-landing-aab8ee1e594369ab48fa3ce60f3acdc6">pilots had received cockpit alerts</a> indicating a failure of the aircraft’s cabin auto-pressurization system.</p>
<p>In a situation like that, where there are suspected cabin pressurization issues, it may be possible for airline maintenance crews to check all cabin doors, windows, seals and potentially door plugs as part of a thorough troubleshooting process, but they would be subject to Boeing’s procedures for inspecting a door plug.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Airline seats sit next to an opening in the side of an aircraft." src="https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569658/original/file-20240116-23-6pkv4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A view of the opening in the side of a Boeing aircraft that lost a door plug in midflight.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/BoeingEmergencyLanding/d6bae2b392f74ac88efa0f8f7ffbb5af/photo">NTSB via AP</a></span>
</figcaption>
</figure>
<h2>What do FAA investigations involve?</h2>
<p>The design, testing, certification and approval process for any new aeronautical product is supposed to be in compliance with strict <a href="https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-25?toc=1">legal and FAA regulatory standards</a>.</p>
<p>As part of the investigations in this case, the FAA will <a href="https://www.npr.org/2024/01/12/1224444590/boeing-faa-737-max-9-alaska-airlines-door-plug">review the engineering and manufacturing processes</a> for the Boeing 737 Max 9, including the processes for vendors and suppliers, to determine if those standards were met. The <a href="https://www.seattletimes.com/business/boeing-aerospace/faa-reviews-data-from-preliminary-inspections-of-boeing-737-max-9/">FAA will review documentation</a> on quality control and assurance processes and analyze components. </p>
<p>The FAA has said it is <a href="https://www.faa.gov/newsroom/faa-increasing-oversight-boeing-production-and-manufacturing">considering bringing in a third party</a> to conduct an audit of the engineering and manufacturing processes for the Boeing 737 Max 9. The findings and recommendations from the <a href="https://www.npr.org/2024/01/08/1223427243/boeing-flight-door-plug-alaska-airlines">National Transportation Safety Board incident investigation</a> may also provide valuable information.</p>
<h2>How do airlines deal with having so many airplanes that are now out of service pending their various inspections?</h2>
<p>With all these aircraft grounded, you need hangars and parking places for temporary storage. And it costs. In the U.S. alone we’re talking about <a href="https://www.newsweek.com/list-airlines-boeing-max-9-1858436">171 airplanes</a> on the ground. </p>
<p>That is a huge financial loss to airlines, which are otherwise benefiting from a <a href="https://edition.cnn.com/2024/01/12/business/alaska-and-united-flights-canceled-737-max/index.html">surge in air service demand and increased passenger interest</a>.</p>
<p>Airlines’ fleet plans – entailing which aircraft they send on which routes and in what sequence – will be disrupted. Some high-traffic routes normally served by these aircraft will have to be done by other aircraft with limited seat and load capacities. That can reduce expected revenue.</p>
<p>The current scenario will also affect flight crew scheduling. Some crew members may have their work hours reduced or eliminated, at least for a period of time.</p>
<p>Once investigators have determined what went wrong, and how to fix whatever it was, that corrective action will also take a lot of maintenance work, in addition to the normal maintenance work for keeping the rest of the planes fit for flying.</p>
<p>It also appears that the <a href="https://www.faa.gov/newsroom/updates-grounding-boeing-737-max-9-aircraft">FAA may want to inspect each plane</a> after it is fixed before certifying it to return to service. That will require significant amounts of inspection time.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two planes sit parked on the tarmac at an airport." src="https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/569660/original/file-20240116-21-b90elk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Two Boeing 737 Max 9 aircraft sit on the ground at an Oregon airport on Jan. 9, 2024, awaiting approval to take to the skies once again.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/alaska-airlines-boeing-737-max-9-aircrafts-n705al-and-news-photo/1913163434">Mathieu Lewis-Rolland/Getty Images</a></span>
</figcaption>
</figure>
<h2>How does an airliner manufacturer regain public confidence? Have other companies dealt with this before?</h2>
<p>In the 1970s, McDonnell Douglas had airworthiness issues with the DC-10 aircraft. Its <a href="https://www.smithsonianmag.com/air-space-magazine/book-excerpt-flight-981-disaster-180967121">cargo door sometimes opened midflight</a>, resulting in injuries and <a href="https://mitpressbookstore.mit.edu/book/9781588345608">fatalities</a>.</p>
<p>The incidents were a big public relations problem for McDonnell Douglas, but using recommendations from the accident investigations, the company managed to redesign the door. </p>
<p>In the 1990s, ATR had its own issues with the <a href="https://www.faa.gov/lessons_learned/transport_airplane/accidents/N401AM">ATR 72’s de-icing system</a>. The company completely redesigned the system and gradually came back into the market.</p>
<p>Airbus has also faced similar challenges: Some <a href="https://simpleflying.com/a320neo-engine-troubles/">Airbus A320neos using Pratt and Whitney 1100G engines</a> had vibration problems that required review with engine manufacturers and regulators.</p>
<p>Most aircraft manufacturers are aware technical issues can surface after deploying a product into the market. That is why it’s important for them to get continuous feedback from operators on reliability and safety. </p>
<p>Boeing’s situation is difficult in part because of previous problems with other 737 Max models, including fatal crashes in 2018 and 2019. In my view, the company will need a lot of transparency and leadership to address these hits to its reputation.</p>
<p>To me, the company’s best chance for surviving this crisis would be to take full responsibility for what has happened and avoid blaming its suppliers. Boeing could involve airline executives, pilots, engineers, cabin crew, media and others in a wide-ranging discussion of quality and safety. If Boeing could win the confidence of these key stakeholders who operate its aircraft, that could help reestablish credibility for its brand with the traveling public.</p>
<p>In early 2023, Boeing was planning to <a href="https://www.reuters.com/business/aerospace-defense/boeing-add-737-max-line-it-boosts-production-2023-01-30/">ramp up production of the 737 Max line</a>. My suggestion would be that the company make product safety and quality an immediate priority and worry later about maximizing production goals and profits, after Boeing’s reputation is restored.</p><img src="https://counter.theconversation.com/content/221069/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Kwasi Adjekum has previously received funding from the National Academies of Sciences Gulf Research Program. </span></em></p>
Boeing is under increased public and government scrutiny in the wake of dangerous events that have people worried about the safety of air travel.
Daniel Kwasi Adjekum, Assistant Professor of Aviation, University of North Dakota
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/212358
2023-08-28T06:04:16Z
2023-08-28T06:04:16Z
‘Every flight is a learning event’: why the V-22 Osprey aircraft won’t be grounded despite dozens of crashes and 54 fatalities
<figure><img src="https://images.theconversation.com/files/544976/original/file-20230828-20049-yzlt1r.jpg?ixlib=rb-1.1.0&rect=23%2C53%2C3712%2C2287&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/us-air-force-bell-boeing-v22-2293652609">Shutterstock</a></span></figcaption></figure><p>At the weekend a <a href="https://www.abc.net.au/news/2023-08-27/nt-us-marines-killed-plane-crash-melville-island-tiwi-osprey/102781722">V-22 Osprey aircraft crashed</a> on Melville Island north of Darwin. Of the 23 US Marine Corps personnel onboard, three died, five were taken to Darwin hospital in a serious condition, and some others had more minor injuries. </p>
<p>The craft was part of the <a href="https://www.marforpac.marines.mil/MRFDarwin/Category/10812/">Marine Rotational Force - Darwin</a>, a unit of up to 2,500 US marines that has been based in the Northern Territory from April to October each year since 2012. This is the most serious accident in that 11-year period.</p>
<p>The Osprey is a relatively new type of aircraft, with a patchy track record for safety. But the advantages it offers for the military – and perhaps for civilians – mean we will only be seeing more of it in the future.</p>
<h2>What is the V-22 Osprey?</h2>
<p>The Osprey has long been controversial, initially for its high cost and long development time, and in recent years <a href="https://taskandpurpose.com/tech-tactics/v-22-osprey-crash-history/">for safety concerns</a>. </p>
<p>These issues reflect the <a href="https://www.youtube.com/watch?v=3vzqhddVG7o">revolutionary design</a> of the craft: it is a kind of plane–helicopter hybrid called a tiltrotor, which means the wing tilts upward for takeoff and landing and back down again for level flight. If this sounds complex, it is.</p>
<p>The Osprey is at the <a href="https://www.boeing.com/defense/v-22-osprey/">leading edge</a> of aviation technology, with nothing else in operational service like it. The aircraft was built to replace helicopters and is used by the US Air Force, Navy and Marine Corps, and the <a href="https://news.usni.org/2020/07/14/japan-self-defense-force-accepts-delivery-of-first-v-22-osprey">Japanese Ground Self-Defense Force</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A sand coloured tarmac and a white plane with two rotors on top seen from the side" src="https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544980/original/file-20230828-17-dk08cw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A US Marines V-22 Osprey at the Naval Air Station Miramar, California.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/miramar-california-usa-oct-15-2006-365983805">Shutterstock</a></span>
</figcaption>
</figure>
<h2>Why is the Osprey so useful?</h2>
<p>The Marine Corps is by far the largest user, being attracted to the aircraft’s much longer range, much higher speed and good carrying capacity compared to conventional helicopters. </p>
<p>The Marine Corps is famous for landing soldiers across beaches during combat but in the modern era this is difficult. Potential adversaries now have excellent beach defences, and bringing ships close enough to shore to land soldiers via traditional naval landing craft or conventional helicopters is becoming unrealistic. </p>
<p>The Osprey solves this by allowing amphibious ships to remain hundreds of kilometres at sea and launch assaults onto the beach “from over the horizon”. A landing can now surprise an enemy, while the Osprey’s range allows many more possible landing sites to be accessed.</p>
<p>The Marines first brought the Osprey into service in 2007, and it has been central to the adoption of <a href="https://crsreports.congress.gov/product/pdf/R/R47614">a whole new way of war</a>. They have dispensed with heavy mechanised forces like tanks in favour of rapid manoeuvres, light vehicles, long-range missile technology and island hopping. </p>
<p>This approach of so-called Expeditionary Advanced Base Operations (EABO) is the <a href="https://mca-marines.org/wp-content/uploads/Maneuverist-19.pdf">Marine Corps answer</a> to China’s growing assertiveness in East Asia and to keeping the Corps relevant in the modern era. The Marines in Darwin now <a href="https://www.marines.mil/News/News-Display/Article/3162643/mrf-d-22-tests-eabo-concepts-on-south-pacific-island/">practise EABO</a>.</p>
<h2>Why is the Osprey’s safety record so patchy?</h2>
<p>That’s the upside. The downside of being leading-edge technology is having little historical experience of similar aircraft to fall back on. </p>
<p>Every Osprey flight is a learning event for the pilots, the maintenance personnel and the aircraft’s manufacturer. </p>
<p>For example, the US Air Force <a href="https://breakingdefense.com/2022/08/exclusive-air-force-special-operations-command-grounds-cv-22-ospreys-due-to-safety-issue/">grounded their Ospreys</a> for two weeks last year over worries about gearbox matters. This has been an ongoing problem that seems to get worse the more an aircraft is flown and the gearbox used; <a href="https://www.military.com/daily-news/2023/03/24/military-quietly-stops-buying-ospreys-aircraft-faces-uncertain-future.html">technical fixes</a> are in the works. </p>
<p>The central concern today is flying safety and here the Osprey has a mixed record. The aircraft had four crashes and 30 deaths during its initial development. </p>
<p>Since entering operational service in 2007 there have been an <a href="https://edition.cnn.com/2023/08/27/asia/aircraft-incident-us-defense-personnel-australia-intl-hnk/index.html">additional ten crashes</a> and 24 deaths. </p>
<p>Two of these ten were on combat operations where the cause was uncertain. The others were due to pilot error or technical problems. </p>
<p>A fatal <a href="https://www.thedrive.com/the-war-zone/harrowing-video-of-deadly-2017-mv-22-osprey-crash-emerges">crash off Rockhampton</a> in 2017 can be seen in <a href="https://www.youtube.com/watch?v=kGVpFmOShAg">a terrifying video</a> that also shows operating the Osprey is a complicated business.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A wide angle view of a cabin with two seats and a series of screens and complex controls in front" src="https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/544977/original/file-20230828-25-badfi1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The cockpit of a V-22 Osprey on display at Dubai Airshow in 2015.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Will the Osprey get safer?</h2>
<p>As the Osprey has flown more, more knowledge has been gained and the accident rate has declined. However, its accidents have tended to come in bunches. In the eight months from December 2016 to September 2017 there were three crashes; in the 18 months from March 2022 to now, there have been another three.</p>
<p>This all compares very unfavourably with American civil aviation, which has a much better safety record. In 2020, a <a href="https://www.flightglobal.com/safety/pentagon-convenes-safety-council-to-address-soaring-aviation-accident-rate/150010.article">report</a> by the National Commission on Military Aviation Safety said the main culprits for the US military’s air accidents were insufficient flying hours to keep aircrew proficient, inadequate personnel training, inconsistent funding for spare parts supply and risky maintenance practices. </p>
<p>The implication is that safety can be improved. It just needs to be properly addressed.</p>
<p>Historically, the safety record of revolutionary aircraft like the Osprey improves as more operating experience is gained and unknown technical problems are found and addressed. That was certainly the Australian experience with the F-111 strike aircraft, which had an early run of crashes followed by many years of safe operation.</p>
<h2>Will we see more tiltrotors like the Osprey in future?</h2>
<p>This is important as the Osprey looks set to be the first of its type, not the last. The US Army has chosen a new generation tiltrotor, <a href="https://www.nationaldefensemagazine.org/articles/2022/12/5/bell-tiltrotor-wins-billion-dollar-helo-contract">the V-280 Valor</a>, to replace its ageing Blackhawk helicopters. </p>
<p>Over time, the Valors will inevitably be deployed to Australia on training exercises. Meanwhile, Australia is <a href="https://www.abc.net.au/news/2023-08-07/new-army-black-hawks-arrive-as-taipan-probe-continues/102695564">acquiring Blackhawks</a> to replace the Australian Army’s Taipan helicopters, which are apparently difficult to maintain.</p>
<p>When those new Blackhawks eventually are themselves replaced, it is likely Australia will go the way of the US and buy tiltrotors too. Civil aviation is getting <a href="https://helicopters.leonardo.com/en/products/aw609">interested in tiltrotors</a> as well.</p>
<p>Tiltrotors like the Osprey and its successors are likely to fly in Australian skies well into the future.</p><img src="https://counter.theconversation.com/content/212358/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Layton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
54 people have died in crashes of the controversial ‘tiltrotor’ V-22 Osprey aircraft – but the military advantage it offers is too great to be discounted.
Peter Layton, Visiting Fellow, Griffith Asia Institute, Griffith University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/151742
2020-12-10T10:54:47Z
2020-12-10T10:54:47Z
Chuck Yeager was a Hollywood idea of a brave test pilot – today they must be skilled engineers too
<figure><img src="https://images.theconversation.com/files/373937/original/file-20201209-17-x5j9ur.jpg?ixlib=rb-1.1.0&rect=7%2C14%2C4985%2C4019&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Test pilot Chuck Yeager in the cockpit of the Bell X-1, in which he became the first recorded pilot to break the sound barrier – although others had likely died trying.</span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Chuck_Yeager#/media/File:Chuck_Yeager_X-1_(color).jpg">Jack Ridley/USAF</a></span></figcaption></figure><p>Charles “Chuck” Yeager, <a href="https://www.bbc.co.uk/news/world-us-canada-55225903">who has died aged 97</a>, epitomised the movie test pilot of the 1940s and 1950s. A fighter pilot hero of the second world war and later Korea, he was dashing, loyal and supremely skilled. In a life that was pure Hollywood, he named his various fighter aircraft “<a href="http://www.chuckyeager.com/1943-1945-the-war-years">Glamorous Glenn</a>” after his then fiancee, later wife, Glennis Dickhouse.</p>
<figure class="align-right ">
<img alt="Brigadier General Chuck Yeager, in uniform" src="https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=764&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=764&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=764&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=960&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=960&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373938/original/file-20201209-21-581ssd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=960&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Brigadier General Chuck Yeager, before his retirement in the 1970s.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Chuck_Yeager.jpg">United States Air Force</a></span>
</figcaption>
</figure>
<p>Parts of his life were featured in the Oscar-winning movie <a href="https://www.imdb.com/title/tt7423322/">The Right Stuff</a>, in which he even took a cameo role, playing a bar drunk in the famous Happy Bottom Riding Club – a ranch hotel run by another famous pilot, <a href="https://archive.nytimes.com/www.nytimes.com/books/00/09/17/bib/000917.rv104240.html">Florence “Pancho” Barnes</a>. He was – along with his friend <a href="https://bobhooverlegacyfoundation.org/bobs-story.html">Bob Hoover</a> – one of the last of that generation of larger-than-life test pilots, usually former fighter pilots, who traded on their bravery and skill, rather than perhaps their scientific knowledge and teamwork. </p>
<p>It was a risky job, and many died. British test pilot Geoffrey de Havilland Jr died when testing his father’s company’s tailless DH 108 “Swallow” in September 1946, after it <a href="https://www.thisdayinaviation.com/tag/geoffrey-raoul-de-havilland-jr/">went out of control and broke up over the Thames Estuary</a>. Valentine Baker died in 1942 <a href="https://www.dailytelegraph.com.au/news/welsh-pilot-valentine-baker-served-in-all-three-armed-forces-in-wwi-and-later-taught-a-future-king-to-fly/news-story/e2a1bed644150a5afcfe92098dee0b7e">testing his company’s MB3 aircraft</a>, leading his business partner, Sir James Martin, to redirect the company to <a href="https://martin-baker.com/about/">making ejection seats</a>.</p>
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<p>Others survived through luck and skill. In Nazi Germany, <a href="https://www.britannica.com/biography/Hanna-Reitsch">Hanna Reitsch</a> had a cockpit fitted and test-flew the jet-powered V1 flying bomb, flew an early prototype helicopter <a href="https://www.youtube.com/watch?v=xtt-OgLNGqs">inside the 1936 Olympic stadium</a>, and nearly lost her life crash-landing a rocket-powered Messerchmitt 163 “Komet”. </p>
<p>But the next generation of test pilots were different: almost always university graduates, they worked in increasingly large and complex teams, generally alongside a much less well known but equally important <a href="http://www.sfte.org/">flight test engineer</a>, with many moving between these two pivotal roles.</p>
<p>The first of these were typified by two contemporaries. There was American <a href="https://neilarmstrongpurdue.weebly.com/">Neil Armstrong</a>, who became universally known as the first man to walk on the Moon. Meanwhile, Briton <a href="https://www.dailymail.co.uk/news/article-3457419/Celebrated-aviator-Eric-Winkle-Brown-known-world-s-greatest-test-pilot-flying-500-different-types-aircraft-dies-aged-97.html">Eric Brown</a> was the first pilot to take off and land from a carrier in a jet aircraft, conducted 2,407 aircraft carrier landings and flew <a href="https://en.wikipedia.org/wiki/List_of_aircraft_flown_by_Eric_%22Winkle%22_Brown">487 types of aeroplane</a> – more than any other pilot to date.</p>
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<p>One of the post-war greats of the new generation was John Farley. An engineering apprentice turned fighter pilot and later test pilot, he led much of the test flying of the UK’s successful Hawk and Harrier aircraft, and performed <a href="https://www.youtube.com/watch?v=RZvq3xMVogo">flying displays at Farnborough</a> which are still legendary. </p>
<p>Many others are relatively anonymous. Few outside of the industry have heard of <a href="https://owensoundsuntimes.prod.postmedia.digital/news/local-news/f-35-test-pilot-billie-flynn-retiring-to-area-after-a-career-spent-pushing-the-limit/wcm/28e973cd-13fc-478e-87b9-bd271424e5f8">Canadian test pilot Billie Flynn</a> but he has test flown and <a href="https://youtu.be/PUoa-T_aRjM">often displayed</a> almost every major fighter of the last 30 years. </p>
<h2>What do test pilots do?</h2>
<p>First and foremost these men and women are pilots, of course, capable of flying new, modified and often not yet fully understood aircraft. They must also be research engineers because while flying that aeroplane (or helicopter, <a href="https://www.hybridairvehicles.com/our-aircraft/airlander-10/">airship</a> or spacecraft) they must be able to conduct experiments with it. </p>
<p>This means flying precise conditions and taking measurements and observations of everything from speed and altitude to the behaviour of complex internal systems. They might be doing that on their own, or in conjunction with a crew, both on board and on the ground with instruments connected to the aircraft by telemetry.</p>
<p>When Chuck Yeager flew the Bell X-1 in 1947, the whole programme was owned by the engineers. The test pilot would be brought in very late on in the programme when the aircraft was nearly ready to fly. Today, the role is very different, with test pilots often involved in planning flights from the early stage, influencing cockpit and procedure design, and testing prototypes in flight simulators long before a physical aircraft takes to the skies. </p>
<p>That might sound as if they could go years without actually flying, but test pilots will work across multiple programmes, some totally new, some more mature. This is why test pilots must maintain the expertise required to understand and pilot not one but many aircraft. </p>
<p>Yeager and his contemporaries would have been very familiar with that. Then, as now, most pilots qualified on very few types of aircraft. But a test pilot needs a wide range of experience to be able to provide their skills to different research programmes, and to offer insights from comparison between them.</p>
<p>How does somebody become a test pilot today? Not starting as a fighter pilot, but typically as an aerospace, electronic or mechanical <a href="https://i-want-to-study-engineering.org/whyeng/">engineer</a>. Those who will become the most senior test pilots are then likely to join one of the <a href="https://www.raf.mod.uk/recruitment/roles/roles-finder/aircrew/pilot">military flying services</a>, commanding several aircraft types and rated as highly skilled fliers. They are then eligible to apply for a place at one of the world’s eight <a href="https://www.setp.org/about-setp/setp-recognized-test-pilots-schools.html">test pilot schools</a>, for which they’ll need their government’s generous funding – fees for the one-year course are <a href="https://www.ntps.edu/information/course-schedule-and-costs.html">at least US$1 million</a> (£750,000). </p>
<p>Here they learn the fundamental skills and theory of test flying on a dozen or more aircraft types and, after graduating, go to work at a national military flight test centre. The companion profession is the flight test engineer, who may go on to find other, usually civilian, routes to <a href="https://www.caa.co.uk/General-aviation/Learning-to-fly/So-you-want-to-learn-to-fly-/">learn to fly</a>.</p>
<p>Sometimes they will progress to <a href="https://www.youtube.com/watch?v=6fnG3iosK4E">become test pilots themselves</a>, typically taking on roles that are more scientifically complex but that don’t necessarily require the intense flying skill of the ex-military pilot. Subsequently, they may stay in that role, progress to <a href="https://virgin.com/about-virgin/latest/virgin-galactic-welcomes-two-new-pilots">senior roles in aerospace</a>, or some become astronauts, such as British helicopter test pilot <a href="https://majortim.space/tim-peake/">Major Tim Peake</a>.</p>
<p>So the role of test pilot has changed since Yeager and colleagues were breaking records in the 1940s. Yet it has also stayed the same: every new or modified aircraft or spacecraft will require test pilots to first take to the skies, <a href="https://www.airshowspresent.com/test-flying-memorial---farnborough-air-sciences-trust.html">and sometimes take considerable risks</a>, so that flight crews and their passengers never need to.</p><img src="https://counter.theconversation.com/content/151742/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Guy Gratton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Sound barrier-breaking fighter ace Chuck Yeager, who has died aged 97, epitomised a very different era of test pilots.
Guy Gratton, Visiting Senior Research Fellow, Brunel University London
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/150688
2020-11-27T18:19:38Z
2020-11-27T18:19:38Z
Boeing 737 Max: why was it grounded, what has been fixed and is it enough?
<p>The Boeing 737 Max began flying commercially in May 2017 but has been grounded for over a year and a half following two crashes within five months. On October 29 2018, <a href="https://www.bbc.com/news/world-asia-46014463">Lion Air Flight 610</a> took off from Jakarta. It quickly experienced problems in maintaining altitude, entered into an uncontrollable dive and crashed into the Java Sea about 13 minutes after takeoff. Then on March 10 2019, <a href="https://nymag.com/intelligencer/2019/04/what-passengers-experienced-on-the-ethiopian-airlines-flight.html">Ethiopian Airlines Flight 302</a> from Nairobi suffered similar problems, crashing into the desert around six minutes after leaving the runway.</p>
<p>In total, 346 people lost their lives. After the second crash, US regulator the Federal Aviation Administration (FAA) decided to ground all 737 Max planes, of which around 350 had been delivered at the time, while they investigated the causes of the accidents.</p>
<p>Now, 20 months later, the FAA <a href="http://news.aa.com/news/news-details/2020/Return-of-the-Boeing-737-MAX-to-service-OPS-DIS-11/default.aspx#:%7E:text=Today%2C%20the%20Federal%20Aviation%20Administration,its%20grounding%20in%20March%202019.&text=This%20includes%20investing%20in%20extensive,it%20returns%20to%20commercial%20use">has announced</a> that it is rescinding this order and has set out steps for the return of the aircraft to commercial service. Brazil has responded quickly, <a href="https://simpleflying.com/brazil-boeing-737-max-recertification/amp/">also approving</a> the 737 Max. So, what went wrong – and can we be confident that it has been fixed?</p>
<p>The causes of the two accidents were complex, but link mainly to the 737’s <a href="https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/">manoeuvring characteristics augmentation system</a> (MCAS), which was introduced to the 737 Max to manage changes in behaviour created by the plane having much larger engines than its predecessors.</p>
<p>There are some important points about the MCAS which we must consider when reviewing the “fixes”. The MCAS prevented stall (a sudden loss of lift due to the angle of the wing) by “pushing” the nose down. Stall is indicated through an angle of attack (AoA) sensor – the 737 Max is fitted with two, but MCAS only used one. If that AoA sensor failed, then the MCAS could <a href="https://www.york.ac.uk/assuring-autonomy/news/blog/accidental-autonomy/">activate when it shouldn’t</a>, unnecessarily pushing the nose down. The design meant that there was no automatic switch to the other AoA sensor, and MCAS kept working with the erroneous sensor values. This is what happened in both crashes.</p>
<p>The design of the MCAS meant that it was repeatedly activated if it determined that there was a risk of a stall. This meant that the nose was continually pushed down, making it hard for pilots to keep altitude or climb. The system was also hard to override. In both cases, the flight crews were unable to override the MCAS, although other crews had successfully managed to do so in similar situation, and this contributed to the two accidents.</p>
<h2>The fixes</h2>
<p>Have these things been fixed? The FAA has published an <a href="https://www.faa.gov/foia/electronic_reading_room/boeing_reading_room/media/737_RTS_Summary.pdf">extensive summary</a> explaining its decision. The MCAS software has been modified and now uses both AoA sensors, not one. The MCAS also now only activates once, rather than multiple times, when a potential stall is signalled by both the AoA sensors. Pilots are provided with an “AoA disagree warning” which indicates that there might be an erroneous activation of MCAS. This warning was not standard equipment at the time of the two accidents – it had to be purchased by airlines as an option. </p>
<p>Importantly, pilots will now be trained on the operation of the MCAS and management of its problems. Pilots claimed that initially they were <a href="https://www.bbc.co.uk/news/business-48281282">not even told</a> that MCAS existed. This training will have to be approved by the FAA.</p>
<p>So, is all well? Probably. As the 737 Max accidents put Boeing and the FAA under such intense scrutiny, it is likely that the design and safety activities have been carried out and checked to the maximum extent possible. There is no such thing as perfection in such complex engineering processes, but it is clear that this has been an extremely intensive effort and that Boeing found and corrected a few other potential safety problems that were unrelated to the accidents. </p>
<p>Of course, we are not there yet. The more than 300 aircraft already delivered have to be modified, and the 450-or-so built but not delivered also need to be updated and checked by the FAA. Then the pilots need to be trained. And the airlines need passengers – but will they get them? That is an issue of trust.</p>
<h2>Safety culture and trust</h2>
<p>The <a href="https://www.youtube.com/watch?v=ep7oLR1xCW0">US Congressional Enquiry</a> was scathing about the culture at both Boeing and the FAA and the difficulty of the FAA in overseeing Boeing’s work. <a href="https://fisher.osu.edu/blogs/leadreadtoday/blog/a-textbook-case-for-disaster-psychological-safety-and-the-737-max">Some commentators</a> have also referred to an absence of psychological safety: “The assurance that one can speak up, offer ideas, point out problems, or deliver bad news without fear of retribution.” We have evidence that the engineering problems have been fixed, but safety culture is more nebulous and slow to change. </p>
<p>How would we know if trust has been restored? There are several possible indicators. </p>
<p>Due to the effects of COVID-19, airlines are running a reduced flight schedule, so they may not need to use the 737 Max. If they choose not to do so, despite its reduced operating costs compared to earlier 737 models, that will be telling. Certainly, all eyes will be on the first airline to return the aircraft to the skies. </p>
<p>Some US airlines <a href="https://simpleflying.com/how-to-tell-if-youre-flying-on-the-boeing-737-max/">have said</a> they will advise people which model of aircraft they will be flying. If passengers opt to avoid the 737 Max, that will speak volumes about public trust and confidence. </p>
<p>The FAA <a href="https://www.faa.gov/news/updates/?newsId=93206">press release</a> also says there has been an “unprecedented level of collaborative and independent reviews by aviation authorities around the world”. But if the international authorities ask for further checks or delay the reintroduction of the aircraft in their jurisdictions, that will be particularly significant as it reflects the view of the FAA’s professional peers. Brazil’s rapid response is a positive sign for this international engagement.</p>
<p>Hopefully, the first few years will prove uneventful and trust can be rebuilt. But only time will tell.</p><img src="https://counter.theconversation.com/content/150688/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John McDermid receives, or has received, funding from government research agencies, industry including in the aerospace sector and the Lloyd's Register Foundation, relevant to the safety of aircraft and autonomous systems. He has not received any funding directly relevant to the Boeing 737 Max.</span></em></p>
Almost two years after crashing twice within five months and being pulled out of service, the Boeing 737 Max’s return to the skies has now been approved.
John McDermid, Director, Assuring Autonomy International Programme, University of York
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/147157
2020-10-01T12:24:16Z
2020-10-01T12:24:16Z
The 737 MAX is ready to fly again, but plane certification still needs to be fixed – here’s how
<figure><img src="https://images.theconversation.com/files/360638/original/file-20200929-22-12u1blg.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3594%2C2392&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Boeing 737 MAX is expected to take to the skies again following a review of the MCAS system which was responsible for two crashes in 2019.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/boeing-737-max-jet-comes-in-for-a-landing-following-a-news-photo/1223465937">Jason Redmond / Getty Images</a></span></figcaption></figure><p><em>After being grounded in March 2019 following two fatal crashes, the Boeing 737 MAX is expected to be certified by the Federal Aviation Administration to fly again later this fall. Investigations pointed to a problem with the aircraft’s Maneuvering Characteristics Augmentation System, or MCAS. This <a href="https://theconversation.com/automated-control-system-caused-ethiopia-crash-flight-data-suggests-113688">automated control system</a> was designed to stabilize the plane and compensate for the more powerful engines used on the 737 MAX compared to previous versions.</em> </p>
<p><em>The <a href="https://www.wsj.com/articles/internal-faa-review-saw-high-risk-of-737-max-crashes-11576069202?mod=searchresults&page=2&pos=2">FAA’s certification</a> of the plane has <a href="https://komonews.com/news/nation-world/lawmakers-upset-over-boeing-max-approval-propose-new-rules">come under fire</a> because manufacturers can speed up the process by having only enhancements to a preapproved aircraft reviewed and certified. Ronnie R. Gipson Jr., an expert in aviation law and visiting professor at the University of Memphis Cecil C. Humphreys School of Law, whose work was cited in the House Committee on transportation and infrastructure’s report on this issue, explains what happened and ways to improve these safety regulations.</em></p>
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<h2>What are the criticisms of the FAA certification process stemming from the 737 MAX crashes?</h2>
<p>The process for the certification of a transport category aircraft is a very involved and costly process. The aircraft manufacturers that go down this path have to be committed to spending hundreds of millions of dollars. It starts with an initial design, and the aircraft that is produced is then subjected to dynamic flight testing for compliance with all of the Federal Aviation Administration regulations. Once the airplane satisfies all those requirements, the aircraft is given an original type certificate by the FAA. The aircraft manufacturer is then allowed to produce aircraft and sell them.</p>
<p>As time goes on, technology advances and the manufacturer identifies ways to improve on that original design. So the manufacturer goes back to the FAA and says, “We want to take this initial design that we have and amend it because we made some changes.” At this point, the aircraft manufacturer files what’s called an amended type certificate application for a derivative aircraft from the baseline aircraft. For example, the original type certificate for the first 737 design was submitted to the FAA in 1967. That original design has had multiple derivative aircraft approved by the FAA, with the 737 MAX being the 13th version. </p>
<figure class="align-center ">
<img alt="a timeline showing the certification approval dates and models of the original 737 design and its derivatives." src="https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=191&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=191&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=191&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=240&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=240&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360883/original/file-20200930-24-h3w89e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=240&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Certification timeline of the Boeing 737 series of aircraft.</span>
<span class="attribution"><a class="source" href="https://www.oig.dot.gov/sites/default/files/FAA%20Oversight%20of%20Boeing%20737%20MAX%20Certification%20Timeline%20Final%20Report.pdf">US Department of Transportation, Office of Inspector General</a></span>
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<p>In the amended type certification process, the regulatory authority focuses only on what’s changed. Another thing to keep in mind is that the FAA just doesn’t have the manpower to oversee all the tests that go with an amended type certificate approval. Therefore, the FAA reviews most of the critical changes related to safety and delegates the noncritical changes for review to the manufacturers – in this case to <a href="https://www.faa.gov/news/media/attachments/Final_JATR_Submittal_to_FAA_Oct_2019.pdf">a body in Boeing</a> which consists essentially of Boeing employees. </p>
<p>And that’s what happened here. MCAS wasn’t necessarily presented as a change in the design impacting control in flight. As a result, the MCAS was not a priority for the FAA in the amended certificate approval process. The MCAS capabilities and what it was supposed to control <a href="https://www.oig.dot.gov/sites/default/files/FAA%20Oversight%20of%20Boeing%20737%20MAX%20Certification%20Timeline%20Final%20Report.pdf">were never fully revealed</a>. That’s really where the problem started. It was with the narrative that was being presented to the FAA, and <a href="https://www.wsj.com/articles/faas-handling-of-boeing-737-max-issues-faulted-in-transportation-department-review-11593619195?mod=searchresults&page=2&pos=12">the lack of oversight in the amended type certificate process</a>. The result was that the MCAS system that was initially presented to the FAA at the beginning of the amended type certificate process was not the same system that ended up in the aircraft.</p>
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<img alt="A diagram showing how the MCAS system forces the nose of the aircraft downwards." src="https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=428&fit=crop&dpr=1 754w, https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=428&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/360881/original/file-20200930-16-11w9416.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=428&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A diagram showing how the MCAS system forces the nose of the aircraft downwards.</span>
<span class="attribution"><a class="source" href="https://www.oig.dot.gov/sites/default/files/FAA%20Oversight%20of%20Boeing%20737%20MAX%20Certification%20Timeline%20Final%20Report.pdf">US Department of Transportation, Office of Inspector General</a></span>
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<h2>How will the recent recertification for the 737 MAX ensure that the model is now safe?</h2>
<p>The FAA has had to backtrack and give the MCAS system the intense level of scrutiny that it deserved. The FAA has required the manufacturer to go back and make significant adjustments to the software, in addition to changes to the operator’s manual, which is what the pilots would see.</p>
<h2>How can the certification process be improved?</h2>
<p>I see two paths to take. First, for a transport category aircraft, regulations are changed so that the manufacturer can receive amended type certificates for only 20 years after the original type certificate has been issued by the FAA.</p>
<p>Here’s how that would work: An aircraft manufacturer designs an aircraft for certification in the transport category and applies for the original type certificate in 2020. Once the original type certification is awarded in, say, 2025, then the manufacturer should have 20 years. That means that the manufacturer would have until the year 2045 to seek an amendment to that original type certificate. Beginning in 2046, if the aircraft manufacturer wants to make subsequent design changes, they have to start over and get a new original type certificate.</p>
<p>The second component to resolving this problem would be to step in and review what areas the FAA can delegate oversight authority for system changes in an amended aircraft certification application review.</p>
<h2>What are the obstacles to making these changes?</h2>
<p>One would be money. The FAA has a budget, and these are very costly measures because the FAA will need more engineers and administrators. And for that to happen, Congress has to be prepared to spend the money to make that happen by increasing the FAA’s budget.</p>
<p>There’s also going to be a cost to the industry. Implementing the proposal of a 20-year cap on the validity of that original type certificate is going to impose a greater financial cost on the aircraft manufacturers of transport category aircraft. They’re not going to have as much time to get a return on their investment for the aircraft that they produce. So the aircraft are going to end up costing more, which means the airlines are going to end up paying more for those planes. And that cost is going to trickle down to the flying public in those seats.</p><img src="https://counter.theconversation.com/content/147157/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ronnie R. Gipson Jr. provides policy advice to the Experimental Aircraft Association as a member of this organization's Legal Advisory Council. </span></em></p>
The Boeing 737 MAX, which has been grounded since 2019 following two fatal crashes, is expected to be cleared to fly again. An aviation law expert proposes a way to improve the certification process.
Ronnie R. Gipson Jr., Visiting Assistant Professor of Law, University of Memphis
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/129077
2019-12-19T00:22:07Z
2019-12-19T00:22:07Z
Grounded: what’s behind Boeing’s production shutdown of MAX aircraft
<p><a href="https://boeing.mediaroom.com/2019-12-16-Boeing-Statement-Regarding-737-MAX-Production">Boeing has announced it will halt production of the beleaguered B737-MAX series</a> from January. Boeing’s announcement this week follows the grounding of the aircraft after two fatal crashes. </p>
<p>After the first crash, of Lion Air in Indonesia in October 2018, people blamed poor maintenance and insufficient pilot training. When a second airliner, of Ethiopian Air, crashed in March 2019, similarities quickly transpired. There was no apparent external influence such as poor weather. Neither was there any interference with the flight decks, as in a hijacking. </p>
<p>In both cases the pilots could not keep the <a href="http://avherald.com/h?article=4c534c4a/0065&opt=0">aircraft from nose-diving</a>. Airlines and regulators around the world started grounding the MAX indefinitely. Australia’s Civil Aviation Authority <a href="https://www.casa.gov.au/media-release/boeing-737-max-operations-temporarily-suspended">prohibited any B737MAX aircraft in its airspace</a>, followed by New Zealand’s Civil Aviation Authority. </p>
<p>Surprisingly, the <a href="https://www.wired.com/story/boeing-737-max-8-ethiopia-crash-faa-ground-safety/">last authority to clamp down</a> was the US Federal Aviation Administration, the governmental body in charge of certifying aircraft. </p>
<p>At first, Boeing was optimistic the aircraft would re-enter service by the end of this year, but recertification has been delayed several times. Globally, 387 delivered and about 400 undelivered MAX aircraft are grounded. The production <a href="https://leehamnews.com/2019/12/17/minimum-3-6-month-737-max-production-shutdown-seen/">shutdown is expected to take several months</a>, with ramifications for suppliers and thousands of jobs at risk.</p>
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<em>
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Read more:
<a href="https://theconversation.com/boeing-737-max-the-faa-wanted-a-safe-plane-but-didnt-want-to-hurt-americas-biggest-exporter-either-113892">Boeing 737 Max: The FAA wanted a safe plane – but didn't want to hurt America’s biggest exporter either</a>
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<h2>Aircraft computer system likely at fault</h2>
<p>The suspected cause of the problems on board the two doomed airliners was a system new to the latest iteration of the <a href="https://www.businessinsider.com.au/airbus-beats-worlds-most-popular-plane-a320-737-2019-11?r=US&IR=T">previously best-selling commercial aircraft</a> – the B737. The MAX series, the fourth generation of the aircraft, entered service in 1968 in its first version (B737-100). The 737MAX is the latest version and started flying in 2018. </p>
<p>Boeing’s main competitor, Airbus, developed the A320 family in the same category of the B737, but <a href="https://leehamnews.com/2019/03/20/boeing-didnt-want-to-re-engine-the-737-but-had-design-standing-by/">included new, more fuel-efficient engines</a>. Boeing was under <a href="https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/">pressure to counter this</a> when it developed the MAX series. </p>
<p>It shifted its larger new engines to provide more ground clearance, but this changed the balance of the aircraft and it tended to pitch up. Boeing created a computer system called Manoeuvring Characteristics Augmentation System (<a href="https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/">MCAS</a>), which would detect any unwanted upward pitch and automatically force the nose down. </p>
<p>Shortly after take-off, the Lion Air 737MAX pilots struggled to stay in the air. The aircraft kept pulling down despite the nose not pitching up. Similarly, the pilots of the Ethiopian flight were not able to control the continuous forcing down of the nose. </p>
<p>Crash investigations are yet to be completed, but <a href="http://avherald.com/h?article=4c534c4a/0065&opt=0%5D%5Bhttp://avherald.com/h?article=4bf90724/0009&opt=0">information released so far</a> points to Boeing’s computer system and a faulty gauge that measures the angle at which the aircraft is flying.</p>
<p>Since the grounding, Boeing has worked tirelessly on a software fix, but regulators found other issues. This includes problems with software affecting flaps and other flight-control hardware, and <a href="https://www.flightglobal.com/airframers/us-congress-raises-new-serious-concerns-with-787-and-737-max/135225.article">issues with rudder cables</a> potentially affected by a so-called uncontained engine failure. In the latter, parts of the engine blades detach and may fly at high speed into the fuselage, severing these cables. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/boeing-737-max-air-safety-market-pressures-and-cockpit-technology-113580">Boeing 737 Max: air safety, market pressures and cockpit technology</a>
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</em>
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<h2>Cutting corners at cost of safety</h2>
<p>It is becoming increasingly clear <a href="https://edition.cnn.com/2019/12/11/politics/fatally-flawed-737-max-had-significantly-higher-crash-risk-faa-concluded/index.html">Boeing has cut corners</a>, presumably under pressure from the performance of its Airbus competitor. Boeing has been <a href="https://www.ft.com/content/5ce97f8a-fb28-11e9-98fd-4d6c20050229">accused of delivering the aircraft before it was ready to fly safely</a>. </p>
<p>It has transpired that Boeing may have been <a href="https://www.ft.com/content/000bba0e-f1c7-11e9-ad1e-4367d8281195">aware of computer system problems even before the Lion Air crash</a>, but delivered the aircraft without modification or information to airlines. Even after the crash, Boeing <a href="https://www.bbc.com/news/business-48174797">did not halt deliveries</a>. Instead it worked to fix the software and told pilots there was a potential problem. </p>
<p>The Federal Aviation Administration did not intervene either, despite its own analysis showing that, without intervention, the plane was <a href="https://www.theguardian.com/us-news/2019/dec/11/boeing-737-max-plane-faa-regulators-crash-risk">likely to crash about one or two times a year</a>. Equally astonishing is that the pilot manual for the MAX did <a href="https://www.cbc.ca/news/business/boeing-737-manual-mcas-system-plane-crash-1.5065842">not mention the new system</a>. Instead, <a href="https://albertaviation.com/pilot-explains-it-takes-a-56-minutes-ipad-lesson-to-fly-the-boeing-737-max-8/">training for pilots</a> moving from the previous 737NG to the new 737MAX consisted of a 56-minute iPad video, but no training in flight simulators. </p>
<p>A Joint Authorities Technical Review <a href="https://www.reuters.com/article/us-usa-boeing-airplane-faa/faa-failed-to-properly-review-737-max-jet-anti-stall-system-jatr-report-idUSKBN1WQ0H8">found</a>:</p>
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<p>The lack of a unified top-down development and evaluation of the system function and its safety analyses, combined with the extensive and fragmented documentation, made it difficult to assess whether compliance was fully demonstrated. </p>
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<h2>Boeing taking on part of aircraft certification</h2>
<p>In a hearing by the US House Transportation Committee, a whistleblower revealed he <a href="https://edition.cnn.com/2019/12/11/politics/fatally-flawed-737-max-had-significantly-higher-crash-risk-faa-concluded/index.html">urged Boeing managers to halt production</a> because of mistakes, errors and corner cutting, as well as an overworked workforce. </p>
<p>Of further concern is that the Federal Aviation Administration has <a href="https://www.reuters.com/article/us-usa-boeing-airplane-faa/faa-failed-to-properly-review-737-max-jet-anti-stall-system-jatr-report-idUSKBN1WQ0H8">shifted some of its work to the manufacturer</a>. Boeing now does parts of the certification process. This is not in the interest of safety. Overseas regulators, such the European Union Aviation Safety Agency, have <a href="https://www.reuters.com/article/us-usa-boeing-airplane-faa/faa-failed-to-properly-review-737-max-jet-anti-stall-system-jatr-report-idUSKBN1WQ0H8">criticised this approach</a>.</p>
<p>The MAX disaster has already <a href="https://www.usnews.com/news/top-news/articles/2019-12-17/boeings-european-suppliers-fall-as-us-planemakers-crisis-deepens">cost Boeing billions of dollars</a>. Prior to the grounding, it produced 52 aircraft per month. It has since reduced production to 40, all of which are now parked. </p>
<p>The production halt will have <a href="https://media.arkansasonline.com/img/photos/2019/10/05/resized_272427-2d1-spirit-1005_59-27251_t800.jpg?90232451fbcadccc64a17de7521d859a8f88077d">ripple effects on US suppliers</a>, with tens of thousands of jobs at risk. The fallout is likely to <a href="https://www.ft.com/content/443d08fa-f1d0-11e9-a55a-30afa498db1b">affect the wider US economy</a> and many <a href="https://www.bing.com/amp/s/www.wsj.com/amp/articles/ges-737-max-problem-just-got-bigger-11576587194">suppliers in Europe and in China</a>.</p>
<p>I have flown on many Boeing aircraft and never felt unsafe. But with recent problems with the Dreamliner, the MAX and most recently the 777X, I question if Boeing has shifted from a safety first philosophy to prioritising profits and dividends for its shareholders.</p><img src="https://counter.theconversation.com/content/129077/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Lueck does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The Boeing MAX disaster has already cost the company billions of dollars and will have ripple effects on suppliers and the wider US economy, with tens of thousands of jobs at risk.
Michael Lueck, Professor of Tourism, Auckland University of Technology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/117899
2019-06-10T01:03:24Z
2019-06-10T01:03:24Z
How Qantas and other airlines decide whether to fly near volcanoes
<figure><img src="https://images.theconversation.com/files/278033/original/file-20190605-40710-1t4t4y1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Airlines will not fly when there is volcanic ash in the air above Bali's Mt Agung. </span> <span class="attribution"><span class="source">Joe Le Merou/flickr</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Mount Agung volcano in Bali, Indonesia, has been erupting intermittently since November 2017. The volcano erupted six times in the last month and resulted in the <a href="https://www.abc.net.au/news/2019-05-25/balis-mount-agung-volcano-erupts-forcing-flight-cancellations/11149336">cancellation and delay of some flights</a> in and out of Bali’s Ngurah Rai International Airport.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1134356577232838656"}"></div></p>
<p>Such continuous but sporadic volcanic activity is a challenge for local emergency management. </p>
<p>But it’s also an issue for planes.</p>
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Read more:
<a href="https://theconversation.com/balis-agung-using-volcano-forensics-to-map-the-past-and-predict-the-future-88229">Bali's Agung – using 'volcano forensics' to map the past, and predict the future</a>
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<p>Captain Mike Galvin, head of fleet operations at Qantas Australia, told us volcanic ash in the air is a concern for airlines. </p>
<p>“The primary issue of volcanic ash for aeroplanes is the melting of ash in the engine turbines and the blocking of sensors that measure air speed and altitude. This can result in differences in flight information displayed to each pilot,” Galvin said. </p>
<p>“Qantas pilots are trained in these procedures during simulator training.</p>
<p>"Additional problems arise from reduced visibility due to the opacity of windscreens, and contamination of air entering the cabin.”</p>
<p>Currently the airline industry adopts a “no fly” policy for any visible or discernible volcanic ash. </p>
<p>“Engine and aeroplane manufacturers will not certify any level of ash tolerance,” Galvin said.</p>
<h2>Ash is a serious problem for planes</h2>
<p>Mt Agung is just the latest example of <a href="https://pubs.usgs.gov/ds/545/DS545.pdf" title="Encounters of Aircraft with Volcanic Ash Clouds: A Compilation of Known Incidents, 1953–2009">volcanoes interrupting flights</a> in Indonesia and other countries. </p>
<p>In April 2010, an eruption of Eyjafjallajökull volcano in Iceland caused disruption to European air traffic for several days and cost the aviation industry an estimated <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010EO210002" title="Eruptions of Eyjafjallajökull Volcano, Iceland">US$250 million</a> per day. </p>
<p>Volcanic ash is made up of volcanic glass, crystals and other rock fragments less than 2mm in size. Ash from explosive eruptions can reach into the stratosphere – 10-20km above the volcano, which is within the cruising altitude of commercial aircraft – and be dispersed by winds up to thousands of kilometres away.</p>
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<a href="https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=414&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=414&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=414&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=520&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=520&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277548/original/file-20190603-69051-1smh5w7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=520&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An ash particle just over 0.1mm long erupted during the 18 May 1980 eruption of Mount St Helens (magnified 200 times).</span>
<span class="attribution"><a class="source" href="https://volcanoes.usgs.gov/volcanic_ash/components_ash.html">USGS</a></span>
</figcaption>
</figure>
<p>The 1982 eruption of Mt Galunggung in Java, Indonesia, clearly demonstrated the potential impact of volcanic ash to aircraft. </p>
<p>Flight BA009 en route to Perth from Kuala Lumpur <a href="http://news.bbc.co.uk/2/hi/uk_news/magazine/8622099.stm">flew through ash from the eruption</a>. This caused sulfurous fumes to enter the cabin and the failure of all four engines, which fortunately restarted after a dive to lower altitude.</p>
<h2>Keeping watch on volcanic ash in the skies</h2>
<p>Following several aviation encounters with volcanic ash in the 1980s, the International Civil Aviation Organisation (<a href="https://www.icao.int/">ICAO</a>), in collaboration with the World Meteorological Organisation (<a href="https://public.wmo.int/en">WMO</a>), established nine volcanic ash advisory centres (<a href="https://www.volcanodiscovery.com/news/vaac/latest-reports.html">VAACs</a>), in Anchorage, Buenos Aires, Darwin, London, Montreal, Tokyo, Toulouse, Washington, and Wellington.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=396&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=396&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277546/original/file-20190603-69075-rffp0c.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=396&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map showing the nine volcanic ash advisory centres (VAACs) and the regions they are responsible for.</span>
<span class="attribution"><a class="source" href="http://www.bom.gov.au/aviation/volcanic-ash/index.shtml">Bureau of Meteorology</a></span>
</figcaption>
</figure>
<p>The role of the VAACs is to provide advice to the aviation industry about the location and movement of volcanic ash within their region. The VAACs gather information issued from local volcano observatories, satellite imagery and other available information such as volcano webcams, pilot reports, and online news.</p>
<p>VAACs perform detailed modelling for individual eruptions and issue images in the shape of a polygon (“ash polygon”) showing current ash-affected air, and where ash is predicted to move over the next few hours.</p>
<p>The <a href="http://www.bom.gov.au/aviation/volcanic-ash/">Darwin VAAC</a> covers the volcanically active regions of Indonesia, Papua New Guinea and the southern Philippines.</p>
<h2>How airlines manage risk</h2>
<p>Qantas’ Mike Galvin said he makes safety decisions based on information gathered by his team using all available sources.</p>
<p>With regards to Bali’s Mt Agung, Galvin said getting the timing right is an important aspect of the process. </p>
<p>“Here in Australia we might be 5-6 hours away from the ash in Indonesia so we need to make decisions several hours before the plane departs,” he said.</p>
<p>Galvin works closely with the Darwin and Tokyo VAACs.</p>
<p>“But we also have our own team of five meteorologists on constant shifts, who utilise information from other sources such as satellite images from the Japanese Himawari satellite,” he said.</p>
<p>“If a polygon of ash lies over the destination airport or on its approach or departure path, then we will not land.”</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277756/original/file-20190603-69067-1mkbnzf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Example summary of the volcanic ash advisory from the Darwin VAAC at the beginning of the Agung eruption in November 2017. Ash polygons shown in red. Each picture shows the forecast of ash movement over a period of hours.</span>
<span class="attribution"><a class="source" href="https://reliefweb.int/map/indonesia/volcano-warning-agung-volcano-indonesia-issued-time-30-november-2017-0100-utc-darwin">OCHA/ReliefWeb/Pacific Disaster Centre using Darwin VAAC data</a></span>
</figcaption>
</figure>
<h2>How science can help</h2>
<p>Since the Icelandic eruption there has been increased <a href="https://www.nasa.gov/feature/langley/nasa-studying-volcanic-ash-engine-test-results">research into volcanic ash impacts</a> on aeroplane engines and <a href="https://journals.sagepub.com/doi/10.1177/0954410015623372" title="A re-evaluation of the 2010 quantitative understanding of the effects volcanic ash has on gas turbine engines">how much ash</a> they can tolerate. </p>
<p>While it is possible engines can tolerate low concentrations of ash, experts don’t yet know what the precise limit of ash that a particular engine can withstand. Further research is needed to determine this. </p>
<p>“Science can also assist the aviation industry though better assessment of the concentrations of ash at different altitudes such as at 20,000 and 30,000 feet,” Galvin said.</p>
<p>In the longer term, volcano science can help airlines understand more about volcanic ash hazards and risks to particular regions. For the Asia-Pacific region, average recurrence intervals have been calculated for each magnitude of volcanic eruption. This is measured by a Volcanic Explosivity Index (VEI).</p>
<p>To put VEI in context, the eruptions in the current phase of activity at Agung have been attributed a <a href="https://volcano.si.edu/volcano.cfm?vn=264020">VEI of 3</a> on a logarithmic scale that runs from 0 to 8. It’s estimated we have 1.4 eruptions per year of this magnitude in the Asia-Pacific region.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=536&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=536&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277803/original/file-20190604-69083-blw4nm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=536&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Calculated average return periods for volcanic eruptions of various magnitudes in the Asia-Pacific Region. Eruption data from Smithsonian Volcanoes of the World Catalogue (volcano.si.edu) and LaMEVE database of large explosive eruptions (www.bgs.ac.uk/vogripa/view/controller.cfc?method=lameve). Data completeness analysis carried out for each Volcanic Explosivity Index (VEI) category by Stuart Mead and Christina Magill (2014).</span>
<span class="attribution"><span class="source">Christina Magill</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The 1883 Krakatau eruption in Indonesia and 1991 Pinatubo eruption in the Philippines were significantly larger, VEI 6 eruptions, which have been estimated to recur every 111 years in the region.</p>
<p>This raises the question of how well prepared the aviation industry is, and countries as a whole, for the next even larger <a href="https://pubs.geoscienceworld.org/gsa/geosphere/article/14/2/572/529016/anticipating-future-volcanic-explosivity-index-vei">VEI 7 eruption</a>, such as that at Tambora in Indonesia in 1815, which erupted <a href="https://pubs.geoscienceworld.org/gsa/geology/article/12/11/659/188320/volcanological-study-of-the-great-tambora-eruption">175 cubic km of fragmented volcanic material</a> in just 24 hours.</p>
<p><a href="https://www.nature.com/articles/s41467-019-08564-9" title="Dyke intrusion between neighbouring arc volcanoes responsible for 2017 pre-eruptive seismic swarm at Agung">Recent scientific research</a> on Agung suggests that the molten rock (magma) feeding Agung volcano below may also be connected to the neighbouring volcano, Batur. The connectivity of magma plumbing systems may explain the joint eruptions of both Agung and Batur in 1963 and may present an additional volcanic hazard to consider for Bali.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277556/original/file-20190603-69063-111aya0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Intrusion of molten rock (magma) between the neighbouring volcanoes of Agung and Batur on Bali that was responsible for 2017 pre-eruptive seismic swarm at Agung.</span>
<span class="attribution"><a class="source" href="https://www.nature.com/articles/s41467-019-08564-9">Albino et al., 2019</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/117899/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Handley receives funding from the Australian Research Council. She is affiliated with the Women in Earth and Environmental Sciences Australasia Network (WOMEESA) and the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI).</span></em></p><p class="fine-print"><em><span>Christina Magill is affiliated with the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) and the IAVCEI Commission on Statistics in Volcanology (COSIV). She has previously developed volcanic loss models for industry partners.</span></em></p>
Volcanic ash is made of tiny crystal and rock fragments that during an eruption can reach as high as the cruising altitude of commercial aircraft, and that’s a concern for airlines.
Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie University
Christina Magill, Senior Lecturer, Department of Environmental Sciences, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/116671
2019-05-08T08:26:17Z
2019-05-08T08:26:17Z
Passenger planes need enough cabin crew to operate all the exits in an emergency
<figure><img src="https://images.theconversation.com/files/273196/original/file-20190507-103082-jlw710.jpg?ixlib=rb-1.1.0&rect=9%2C243%2C2814%2C1742&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cabin crew can be lifesavers in any emergency.</span> <span class="attribution"><span class="source">Shutterstock/ChameleonsEye </span></span></figcaption></figure><p>The crash of Aeroflot flight SU1492 in Moscow raises concerns about cabin safety in terms of the number of crew needed in an emergency.</p>
<p>The Sukhoi Superjet-100 aircraft was <a href="https://www.aeroflot.ru/ru-en/news/61325">carrying 73 passengers and five crew members</a> when it burst into flames at Moscow airport on Sunday. At least 41 people are <a href="https://www.news.com.au/travel/travel-updates/incidents/passengers-killed-in-fiery-aeroplane-accident-at-moscows-sheremetyevo-airport/news-story/f8776fb928df225becb301340073f97a">reported to have died</a>.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/around-50-of-homes-in-sydney-melbourne-and-brisbane-have-the-oldest-nbn-technology-115131">Around 50% of homes in Sydney, Melbourne and Brisbane have the oldest NBN technology</a>
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</em>
</p>
<hr>
<p>What happened in the Aeroflot accident and evacuation is now subject to investigation. But what about the broader question of cabin crew safety this incident raises?</p>
<h2>Cabin crew numbers</h2>
<p>In 2010 the Australian Civil Aviation Safety Authority (CASA) <a href="https://www.abc.net.au/news/2010-02-16/aviation-body-defends-cabin-crew-cutbacks/332908">mooted changes</a> to reduce cabin crew numbers from a minimum ratio of 1 for every 36 passengers to 1 per 50 passengers.</p>
<p>The 1/50 had been global standard for years, but until 2010 Australia had the higher standard of 1/36 (since the inception of the jet age). It’s reasonable to assume the Aeroflot aircraft would have been operating under the same international 1/50 regulation.</p>
<p>In 2011 an <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ic/cabincrew/index.htm">inquiry into cabin crew numbers</a> was set up by the Australian Government’s House Standing Committee on Infrastructure and Communications.</p>
<p>In submissions, <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ic/cabincrew/subs/sub004.pdf">Qantas</a> and others argued that 1/50 was the global standard – despite the fact we already had a higher standard.</p>
<p>The <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ic/cabincrew/subs/sub010.pdf">Flight Attendants’ Association of Australia</a> and the <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ic/cabincrew/subs/sub009.pdf">Australian & International Pilots’ Association</a> were among those calling for no change.</p>
<h2>Evacuation tests</h2>
<p>The argument made by those advocating for change from 1/36 to 1/50 was that certification by the regulatory authority in the country of aircraft manufacture required a full evacuation demonstration to be successfully carried out by that manufacturer.</p>
<p>The demonstration had to prove that a full complement of passengers and crew could successfully evacuate the aircraft in 90 seconds.</p>
<p>Additionally, for many years in Australia the civil aviation regulator, now CASA, required an additional partial evacuation demonstration be conducted by the airline wanting to introduce the new aircraft into service.</p>
<p>That demonstration had to show the airline’s own crew could evacuate the aircraft with half the cabin crew complement with half a load of passengers and through half of the doors in 90 seconds.</p>
<p>But the potentially flawed part of that argument was these evacuation demonstrations were carried out with the aircraft intact, sitting evenly on its wheels with no real emergency, no fire, smoke or obstructions in the cabin, no real threat of death adding dire urgency, and no panic among the passengers.</p>
<p>In my experience, they don’t really test how the passengers will react or the crew will function under the severe stress of an emergency like the case in Russia with the Aeroflot aircraft fire.</p>
<p>The Russian crash also shows that the 90-second time standard needs to be reviewed. Aeroflot <a href="https://www.aeroflot.ru/ru-en/news/61325">says the evacuation</a> of the Sukkoi aircraft took only 55 seconds, through only half the doors, and still more than half the passengers didn’t get out.</p>
<h2>A change in the ratio</h2>
<p>The report of the Standing Committee inquiry actually <a href="https://www.aph.gov.au/Parliamentary_Business/Committees/House_of_Representatives_Committees?url=ic/cabincrew/report/prelims.htm">recommended keeping the 1/36 ratio</a> but the government <a href="https://infrastructure.gov.au/aviation/publications/files/Att-A-Cabin-Crew-Ratios.pdf">rejected this, saying</a>:</p>
<blockquote>
<blockquote>
<p>The unequivocal advice from both CASA and OTS (Office of Transport Security) is that having a one cabin crew member to every fifty passenger seats ratio in Australia does not reduce the safety or security of domestic aircraft operations. </p>
</blockquote>
</blockquote>
<p>On flights with less than 216 passengers, CASA has been <a href="https://www.casa.gov.au/standard-page/project-os-0901-review-cabin-crew-ratios-set-out-cao-20163">allowing some airlines</a> to operate on the 1/50 ratio since 2006, although the appropriate legislation has still to be changed to reflect this.</p>
<p>The real issue in play when the cabin crew ratio was being changed in Australia, was the Australian airlines were at a competitive disadvantage against internationals operating into Australia, so the Australian airlines wanted parity.</p>
<p>I can see the commercial argument. But in my 40 years working in air safety, it was the only time I’d seen airlines openly argue a position for what was actually a lower standard of safety than already in place.</p>
<h2>How many exits?</h2>
<p>One of the serious problems that resulted from the cabin crew ratio rule change that went under the regulatory radar is that now on 100 to 149 seat aircraft, only three cabin crew are mandated.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/273278/original/file-20190508-183089-1r74ock.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Emergency exits left and right.</span>
<span class="attribution"><span class="source">Shutterstock/Chatree</span></span>
</figcaption>
</figure>
<p>But such aircraft can have four main cabin doors that can be used as emergency exits in the case of an accident.</p>
<p>So now on those aircraft there is one door, front or rear dependent on airline procedures, without a cabin crew member stationed at it to operate the door and control the evacuation there in an emergency.</p>
<p>The airline procedures assign responsibility for operation of that door and the one on the opposite side of the cabin to the one cabin crew member.</p>
<p>In my opinion this is a serious reduction in safety. There is little doubt that in an emergency of the type suffered by the Sukkoi Superjet, the one cabin crew member would have no hope of operating two exits with the passengers panicking and pressing to get out.</p>
<h2>Lives at risk?</h2>
<p>I believe lives will be lost in future because of the rule changes.</p>
<p>Consider an aircraft operating in Australia that had between 100 and 149 seats – under the current rules it would have only three flight attendants.</p>
<p>If a similar accident to that of the Aeroflot aircraft happened, the two rear exits would be blocked by fire. (The flight attendant at the rear of the crashed aircraft <a href="http://tass.com/emergencies/1057052">reportedly died</a> trying to carry out their duties at the rear exits. </p>
<p>If there had been only one cabin crew member stationed at the front of the aircraft, not an unusual circumstance now, it is very possible that only one forward exit would be promptly opened. That would seriously impact the number of passengers who would escape through the one exit before the cabin was fully involved in the fire with smoke and flames?</p>
<p>The Sukkoi accident shines a light on the decisions that were made at the time of the Australian rule changes.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/can-we-bend-it-the-challenge-for-samsung-and-others-to-make-flexible-technology-116270">Can we bend it? The challenge for Samsung and others to make flexible technology</a>
</strong>
</em>
</p>
<hr>
<p>The rules need to be changed again to mandate a cabin crew member for every floor level exit. So in a 100 to 149 seat aircraft with four entry/exit doors, the minimum cabin crew complement would be four, not three.</p>
<p>Then the 1/50 ratio could then apply for any extra cabin crew once all floor level exits are staffed.</p>
<p>In my opinion this rule change is need internationally, not just in Australia. The International Civil Aviation Organisation needs to act, before more lives are lost.</p><img src="https://counter.theconversation.com/content/116671/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoffrey Dell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Cabin crew play a vital role in helping passengers during any aircraft emergency. But how many do you really need on a flight?
Geoffrey Dell, Associate Professor/Discipline Leader Accident Investigation and Forensics, CQUniversity Australia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/114394
2019-04-08T10:42:55Z
2019-04-08T10:42:55Z
Too many airplane systems rely on too few sensors
<figure><img src="https://images.theconversation.com/files/267199/original/file-20190402-177175-6046gt.jpg?ixlib=rb-1.1.0&rect=291%2C0%2C4700%2C1661&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Planes have many sensors, supplying all kinds of useful data.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/business-jet-airplane-gear-down-landing-1310559680?src=unD8nxhH5kTmylCMzugfLg-1-92">vaalaa/Shutterstock.com</a></span></figcaption></figure><p>The <a href="https://www.nytimes.com/2019/03/25/business/boeing-simulation-error.html">apparent connection</a> between fatal airplane <a href="https://www.nytimes.com/interactive/2019/03/13/world/boeing-737-crash-investigation.html">crashes in Indonesia and Ethiopia</a> centers around the <a href="https://www.washingtonpost.com/business/economy/sensor-cited-as-potential-factor-in-boeing-crashes-draws-scrutiny/2019/03/17/5ecf0b0e-4682-11e9-aaf8-4512a6fe3439_story.html">failure of a single sensor</a>. I know what that’s like: A few years ago, while I was flying a Cessna 182-RG from Albany, New York, to Fort Meade, Maryland, my airspeed indicator showed that I was flying at a speed so slow that my plane was at risk of no longer generating enough lift to stay in the air.</p>
<p>Had I trusted my airspeed sensor, I would have pushed the plane’s nose down in an attempt to regain speed, and possibly put too much strain on the aircraft’s frame, or gotten dangerously close to the ground. But even small aircraft are packed with sensors: While worried about my airspeed, I noticed that my plane was staying at the same altitude, the engine was generating the same amount of power, the wings were meeting the air at a constant angle and I was still moving over the ground at the same speed I had been before the airspeed allegedly dropped.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=329&fit=crop&dpr=1 600w, https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=329&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=329&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=413&fit=crop&dpr=1 754w, https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=413&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/267200/original/file-20190402-177175-m0aof4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=413&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A Cessna 182 in flight.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/131806380@N05/17246847205">Rob Hodgkins/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>So instead of overstressing and potentially crashing my plane, I was able to fix the problematic sensor and continue my flight without further incident. As a result, I started investigating how <a href="https://doi.org/10.1109/MAES.2017.150242">computers can use data from different aircraft sensors</a> to help pilots understand whether there’s a real emergency happening, or something much less severe.</p>
<p>Boeing’s response to its crashes has included designing a software update that will <a href="https://www.nytimes.com/2019/03/25/business/boeing-simulation-error.html">rely on two sensors instead of one</a>. That may not be enough. </p>
<h2>Cross-checking sensor data</h2>
<p>As a plane defies gravity, aerodynamic principles expressed as mathematical formulas govern its flight. Most of an aircraft’s sensors are intended to monitor elements of those formulas, to reassure pilots that everything is as it should be – or to alert them that something has gone wrong.</p>
<p>My team developed <a href="http://wcl.cs.rpi.edu/pilots/">a computer system</a> that looks at information from many sensors, comparing their readings to each other and to the relevant mathematical formulas. This system can detect inconsistent data, indicate which sensors most likely failed and, in certain circumstances, use other data to estimate the correct values that these sensors should be delivering.</p>
<p>For instance, my Cessna encountered problems when the primary airspeed sensor, called a “<a href="https://www.scientificamerican.com/article/what-is-a-pitot-tube/">pitot tube</a>,” froze in cold air. Other sensors on board gather related information: GPS receivers measure how quickly the aircraft is covering ground. Wind speed data is available from computer models that forecast weather prior to the flight. Onboard computers can calculate an estimated airspeed by combining GPS data with information on the wind speed and direction.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=313&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=313&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=313&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=393&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=393&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266148/original/file-20190327-139341-ufpu9u.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=393&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Using information on ground speed and the current wind conditions, a computer can estimate the plane’s airspeed.</span>
<span class="attribution"><span class="source">Shigeru Imai and Carlos Varela</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>If the computer’s estimated airspeed agrees with the sensor readings, most likely everything is fine. If they disagree, then something is wrong – but what? It turns out that <a href="https://doi.org/10.1109/MAES.2017.150242">these calculations disagree in different ways</a>, depending on which one – or more – of the GPS, wind data or airspeed sensors is wrong.</p>
<h2>A test with real data</h2>
<p>We tested our computer program with real data from the 2009 crash of Air France Flight 447. The post-crash investigation revealed that <a href="https://www.npr.org/sections/thetwo-way/2012/07/05/156303873/crash-report-confirm-air-france-447-crashed-due-to-faulty-sensors-pilot-error">three different pitot tubes</a> froze up, <a href="http://www.spiegel.de/international/world/death-in-the-atlantic-the-last-four-minutes-of-air-france-flight-447-a-679980.html">delivering an erroneous airspeed reading</a> and triggering a chain of events ending in the plane plunging into the Atlantic Ocean, killing 228 passengers and crew.</p>
<p>The flight data showed that when the pitot tubes froze, they suddenly stopped registering airspeed as 480 knots, and instead reported the plane was going through the air at 180 knots – so slow the autopilot turned itself off and alerted the human pilots there was a problem.</p>
<p>But the onboard GPS recorded that the plane was traveling across the ground at 490 knots. And computer models of weather indicated the wind was coming from the rear of the plane at about 10 knots.</p>
<p>When we fed those data to our computer system, it <a href="https://doi.org/10.1109/MAES.2017.150242">detected that the pitot tubes had failed</a>, and estimated the plane’s real airspeed within five seconds. It also detected when the pitot tubes thawed again, about 40 seconds after they froze, and was able to confirm that their readings were again reliable.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/7G9FLFIdnx8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">When one sensor fails, other equipment can provide data to detect the failure and even estimate values for the failing sensor.</span></figcaption>
</figure>
<h2>A different sort of test</h2>
<p>We also used our system to identify what happened to <a href="https://en.wikipedia.org/wiki/Tuninter_Flight_1153">Tuninter Flight 1153</a>, which ditched into the Mediterranean Sea in 2005 on its way from Italy to Tunisia, killing 16 of the 39 people aboard.</p>
<p>After the accident, the investigation revealed that maintenance workers had mistakenly <a href="https://www.flightglobal.com/news/articles/tuninter-atr-72-had-been-fitted-with-wrong-fuel-gaug-201462/">installed the wrong fuel quantity indicator</a> on the plane, so it reported 2,700 kg of fuel was in the tanks, when the plane was really carrying only 550 kg. Human pilots didn’t notice the error, and the plane ran out of fuel.</p>
<p>Fuel is heavy, though, and its weight affects the performance of an aircraft. A plane with too little fuel would have handled differently than one with the right amount. To calculate whether the plane was behaving as it should, with the right amount of fuel on board, we used the <a href="https://doi.org/10.1007/s10586-017-1291-8">aerodynamic mathematical relationship between airspeed and lift</a>. When a plane is in level flight, lift equals weight. Everything else being the same, a <a href="https://doi.org/10.1109/MAES.2017.150242">heavier plane should have been going slower</a> than the Tuninter plane was. </p>
<p>Our program models only cruise phases of flight, in which the plane is in steady, level flight – not accelerating or changing altitude. But it would have been sufficient to detect that the plane was too light and alert the pilots, who could have turned around or landed elsewhere to refuel. Adding information about other phases of flight could improve the system’s accuracy and responsiveness.</p>
<h2>What about the Boeing 737 Max 8 crashes?</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=185&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=185&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=185&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=232&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=232&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266135/original/file-20190327-139371-1x1l6r9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=232&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The angle of attack describes how the wings meet the oncoming air.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Airfoil_angle_of_attack.jpg">J Doug McLean/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The full range of data about Lion Air 610 and Ethiopian Airlines 302 is not yet available to the public, but early reports suggest there was a <a href="https://www.nytimes.com/2019/04/04/world/asia/ethiopia-crash-boeing.html">problem with one of the angle-of-attack sensors</a>. My research team developed a method to check that device’s accuracy based on the plane’s airspeed.</p>
<p>We used aerodynamics and a flight simulator to measure how variations in the angle of attack – the steepness with which the wings meet the oncoming air – changed the horizontal and vertical speed of a Cessna 172. The data were consistent with the performance of an actual Cessna 172 in flight. Using our model and system, we can distinguish between an actual emergency – a dangerously high angle of attack – and a failing sensor providing erroneous data.</p>
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<p>The actual numbers for a Boeing 737 Max 8 would be different, of course, but the principle is still the same, using the mathematical relationship between angle of attack and airspeed to double-check each other, and to identify faulty sensors.</p>
<h2>Better still</h2>
<p>As my team continues to develop flight data analysis software, we’re also working on supplying it with better data. One potential source could be <a href="https://www.nsf.gov/awardsearch/showAward?AWD_ID=1816307&HistoricalAwards=false">letting airplanes communicate directly with each other</a> about weather and wind conditions in specific locations at particular altitudes. We are also working <a href="https://news.rpi.edu/approach/2019/01/31/grant-awarded-to-increase-intelligence-in-aerospace-systems/">on methods to precisely describe safe operating conditions</a> for flight software that relies on sensor data.</p>
<p>Sensors do fail, but even when that happens, automated systems can be <a href="https://theconversation.com/your-next-pilot-could-be-drone-software-92330">safer and more efficient than human pilots</a>. As flight becomes <a href="https://theconversation.com/despite-consumer-worries-the-future-of-aviation-will-be-more-automated-113807">more automated and increasingly reliant on sensors</a>, it is imperative that flight systems cross-check data from different sensor types, to safeguard against otherwise potentially fatal sensor faults.</p><img src="https://counter.theconversation.com/content/114394/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Carlos Varela currently receives funding from the Air Force Office of Scientific Research (DDDAS Grant No. FA9550-19-1-0054) and the National Science Foundation (CISE Grant No. CNS-1816307).</span></em></p>
A pilot and researcher knows that airplanes are full of sensors – and finds a way onboard computers can use the data to detect equipment failure and tell pilots what’s a real emergency and what’s not.
Carlos Varela, Associate Professor of Computer Science, Rensselaer Polytechnic Institute
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/113688
2019-03-15T20:23:50Z
2019-03-15T20:23:50Z
Automated control system caused Ethiopia crash, flight data suggests
<figure><img src="https://images.theconversation.com/files/264167/original/file-20190315-28483-ks4bzt.jpg?ixlib=rb-1.1.0&rect=932%2C764%2C6056%2C3887&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Wreckage from Ethiopia Airlines Flight 302 lies near the crash site outside Addis Ababa.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Ethiopia-Plane-Crash/ed5a500617ea440ca8aed9511e1d85f7/151/0">AP Photo/Mulugeta Ayene</a></span></figcaption></figure><p>Emerging evidence from the recent crash in Ethiopia suggests that malfunctioning automatic control systems overwhelmed the crew and doomed the flight. Based on my analysis, it appears that the Ethiopian Airlines crew followed the standard procedures found in the <a href="http://www.b737.org.uk/fcom.htm">Boeing 737 pilots operating handbook and flight crew operations manual</a>.</p>
<p>A typical flight starts with manual control of the plane. The pilot and co-pilot will personally steer the aircraft onto the taxiway, configure the flaps for takeoff, actively control the aircraft as it accelerates down the runway, and smoothly pull back on the control yoke to lift the plane off the ground and into flight. The flight’s altitude and speed data, <a href="https://www.flightradar24.com/blog/flightradar24-data-regarding-the-crash-of-ethiopian-airlines-flight-302/">transmitted from the plane in real time</a> and made available to the public by FlightRadar24.com, shows that happened normally as Ethiopian Airlines Flight 302 left the runway.</p>
<p>Everything appears to have gone as usual on the initial climb away from the takeoff, too. Normally, the pilot will retract the landing gear and maintain a relatively steady speed as the aircraft climbs. The plane might accelerate slightly until it’s going fast enough that the flaps – extended to increase lift at lower speeds – can be safely retracted, letting the wings themselves generate the necessary lift. This process usually takes place in the first minute after takeoff. Once the aircraft has climbed to 1,000 feet above the ground, the pilot will engage the autopilot system.</p>
<p>That’s the point at which the computer takes over – and where, my analysis of the data suggests, things went wrong for Ethiopian Airlines Flight 302. A modern autopilot system gives the computer command of the engine throttles, rudder, elevators and ailerons – basically full control over the aircraft.</p>
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<h2>Simulating the expected flight</h2>
<p>Using <a href="https://doi.org/10.2514/6.2018-0284">modeling tools developed by my research team</a>, I recreated a hypothetical flight profile to simulate the Ethiopian Airlines 737 departure based on the handbook procedure for an identical plane carrying a similar amount of weight. The simulation timing, key speeds and altitudes all follow my best estimate of the procedure that a trained pilot would be expected to follow.</p>
<p>Comparing this data to the actual flight data, I was able to see where the ideal predicted performance differs from the actual motions of the lost flight. My simulation closely matches the actual speeds of the aircraft on its takeoff roll, and recreates its first few miles of airborne flight. The pilot let the aircraft accelerate gently during initial climb, which isn’t specifically called for or prohibited in the official manual. </p>
<p>The flight paths between a typical flight and the actual course sharply diverge only after the aircraft reached an altitude of 1,000 feet above the runway.</p>
<p>Immediately after flap retraction, the pilot should have engaged the autopilot, leaving the computer to command a climb at constant airspeed. Instead, the ill-fated flight began to dive and accelerate, losing altitude and gaining speed until it struck the ground a few miles away from the airport.</p>
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<p>There are several possible reasons a plane could crash like this. One is that an engine could malfunction. But the telemetry data doesn’t indicate the loss of acceleration that an engine failure would cause. Another reason could be that some part of the fuselage, wings or tail broke or collapsed. The data doesn’t show the sort of change in speed or climb rate that would result from such a loss of stability.</p>
<p>The crash does not appear to be due to pilot error, either. I’ve studied <a href="https://doi.org/10.2514/6.2018-3500">pilot overreactions during developing emergencies</a>, and see no evidence of that before the initial dive; the pilots seem to fly an otherwise typical takeoff. If there was some other mechanical failure, the <a href="https://www.nytimes.com/2019/03/14/world/boeing-737-max-ethiopian-airlines.html">pilots didn’t report it</a> to the control tower. There is no indication that they overreacted or overcompensated to some emergency: The radar track shows no evidence of a condition called “wallowing,” characterized by periodic fluctuations in speed and altitude, nor any accidental stall, where airspeed drops sharply before the plane loses altitude.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/264172/original/file-20190315-28471-1vlqmz9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Key parts of an aircraft.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Aircraft_Parts_eng.jpg">Dtom/Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Therefore, it appears that the various automatic control systems conspired to prevent the pilots from asserting direct control over the <a href="https://www.grc.nasa.gov/www/k-12/airplane/alr.html">ailerons</a>, <a href="https://www.grc.nasa.gov/www/k-12/airplane/elv.html">elevators</a> and <a href="https://www.grc.nasa.gov/www/k-12/airplane/rud.html">rudder</a> that keep the aircraft aloft and on course.</p>
<h2>How long on the ground?</h2>
<p><a href="https://web.archive.org/web/20190315184912/http://active.boeing.com/commercial/orders/displaystandardreport.cfm?cboCurrentModel=737&optReportType=AllModels&cboAllModel=737&ViewReportF=View+Report">More than 300</a> Boeing 737 Max aircraft have been <a href="https://www.flightglobal.com/news/articles/malindo-operates-worlds-first-737-max-flight-437454/">flying since 2017</a>, with thousands of safe takeoffs and landings. That suggests the problem for Ethiopian Airlines – and possibly the <a href="https://qz.com/1574441/a-warning-signal-that-could-have-prevented-the-lion-air-crash-was-optional/">2018 Lion Air crash</a> too – is one of the difficult sort of engineering troubles that happen intermittently, or even seemingly randomly, in very complex systems. </p>
<p>Boeing has already said it will <a href="https://www.nytimes.com/2019/03/14/business/boeing-737-software-update.html">update the aircraft’s software</a>. Any fixes will have to be checked not only to ensure that they handle whatever the exact problem is that’s identified by crash investigators, but also to make sure they don’t cause other unexpected errors. That will take its own amount of time. In the meantime, all the Boeing 737 Max aircraft in the world are on the ground, waiting.</p><img src="https://counter.theconversation.com/content/113688/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothy Takahashi received funding from Dragonfly LLC to model aircraft takeoff performance. He is an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA) and member of the Society of Aircraft Performance & Operations Engineers (SAPOE).
</span></em></p>
An analysis of flight data shows that problems began at a point when the pilot would normally have engaged the autopilot system.
Timothy Takahashi, Professor of Practice for Aerospace Engineering, Arizona State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/103102
2018-10-03T20:04:52Z
2018-10-03T20:04:52Z
Curious Kids: what’s the history of aircraft squawk codes and how do they work?
<figure><img src="https://images.theconversation.com/files/239061/original/file-20181003-101558-cgjvt3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Perth air traffic control tower. As a pilot flies towards the destination, the air traffic control tower sends an interrogation signal. The aircraft automatically responds with a series of short pulses that let air traffic control know the identity of the plane and its altitude.</span> <span class="attribution"><a class="source" href="http://newsroom.airservicesaustralia.com/galleries">© Copyright Airservices Australia</a></span></figcaption></figure><p><em>This is an article from <a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a>, a series for children. The Conversation is asking kids to send in questions they’d like an expert to answer. All questions are welcome – serious, weird or wacky! You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Hi, I’m Daniel, 12, and I would like to know the history behind squawk codes on aircraft and how they work. Thanks! – Daniel, age 12, Perth.</strong></p>
</blockquote>
<hr>
<p>Thank you, Daniel, for this question. As you have guessed there is a very interesting back story to “squawk codes”. These codes have been used in radio signalling systems for more than 75 years to identify and determine the location of aircraft in flight.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-glow-in-the-dark-paint-work-92438">Curious Kids: How does glow in the dark paint work?</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=593&fit=crop&dpr=1 600w, https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=593&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=593&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=745&fit=crop&dpr=1 754w, https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=745&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/239060/original/file-20181003-101558-na7wph.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=745&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Nazi plane flies over South London in 1940. Germany used bomber aircraft to attack the UK in the Battle of Britain. The British won, thanks partly to their early radar systems – but these systems initially had a limitation.</span>
<span class="attribution"><span class="source">Wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Code name: Parrot</h2>
<p>Early radar systems used in the second world war were critical to allied success in the Battle of Britain in 1940, when Britain’s Royal Air Force (RAF) defended the United Kingdom against a huge air attack campaign by Nazi Germany’s air force, the Luftwaffe.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=507&fit=crop&dpr=1 600w, https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=507&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=507&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=637&fit=crop&dpr=1 754w, https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=637&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/239057/original/file-20181003-101573-11owyaf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=637&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nazi Germany used aircraft like these Heinkel He 111 to attack the UK in the Battle of Britain.</span>
<span class="attribution"><span class="source">Wikimedia</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But these early radar systems had a major limitation. They could detect aircraft by radio signals being reflected by moving objects, but the reflected signal could not tell you whether an aircraft was friendly or hostile.</p>
<p>This led to the rapid development of secondary surveillance radars, which required an active and cooperative response from aircraft. In other words, the aircraft had to answer back. This would help to identify the “friendlies” in the skies.</p>
<p>The secondary radar system would send a transmission of radio frequency pulses directed at the aircraft. Friendly aircraft were fitted with equipment that would respond with an identification code. If no response was received, radar operators would presume the aircraft was an enemy plane.</p>
<p>This innovation meant that radar operators could now use the main radars (known as “primary radars”) in combination with the secondary radars to detect the presence of aircraft and to distinguish between friends and foes. </p>
<p>This system was known as Identification Friend or Foe (IFF) and the concept remains important to military forces even today. </p>
<p>The aircraft transponder, which received and transmitted signals, was initially code-named Parrot. Soon, airmen started using the nickname “squawk codes”.</p>
<p>While the name Parrot didn’t last, the term “squawk” continues to be used today to describe the activity of the transponder.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-how-does-gravity-pull-things-down-to-earth-101545">Curious Kids: how does gravity pull things down to Earth?</a>
</strong>
</em>
</p>
<hr>
<h2>How it works</h2>
<p>After the war, the concept was adapted for civil aircraft – the kinds of plane we fly on when we go on holiday.</p>
<p>The system identifies an aircraft through a four-digit octal number (each digit from 0 to 7), which provides for up to 4,096 possible codes. These codes can also be used to alert controllers of an aircraft emergency. Subsequently, another mode was added to inform radar controllers of an aircraft’s height, using data from the plane’s altimeter (the instrument that tells you how high a plane is flying).</p>
<p>For those of you who are technically minded, the frequencies used in secondary surveillance radar are 1030 Megahertz for the interrogation (the “hello, who are you?” signal) and 1090 Megahertz for the response (the answer you get back). The response is a sequence of pulses spaced 1.45 microseconds apart – that’s very fast!</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/239053/original/file-20181003-101555-1l2qa76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A temporary en route or secondary radar at Melbourne Airport. Airservices uses en route radar to assist with separation of aircraft in controlled airspace.</span>
<span class="attribution"><a class="source" href="http://newsroom.airservicesaustralia.com/images/ml-apt-mar-lines-install-04-2015-87">© Copyright Airservices Australia 2015</a></span>
</figcaption>
</figure>
<h2>Air traffic control towers</h2>
<p>Imagine a pilot is flying a plane full of passengers on holiday to Sydney. As she or he flies towards the destination, the air traffic control tower at Sydney airport sends an interrogation signal. The aircraft automatically responds with a series of short pulses that let air traffic control know the identity of the plane and its altitude. Then air traffic control can compare the identity code to flight plans to identify the aircraft. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/239056/original/file-20181003-101558-xvh59c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Airservices control tower at Sydney Airport.</span>
<span class="attribution"><a class="source" href="http://newsroom.airservicesaustralia.com/images/sydney_tower-2">© Copyright Airservices Australia 2014</a></span>
</figcaption>
</figure>
<p>The time taken between the interrogation transmission and the received code lets us know the distance between the radar and the aircraft. Air traffic control computer systems use this information, the direction of the interrogation signal, and the altitude to determine exactly where the aircraft is.</p>
<p>Other navigation and airspace management systems have been developed over the years. The most recent is the Automatic Dependent Surveillance Broadcast (ADS-B) system, which incorporates Global Positioning System (GPS) data into the responses from aircraft. </p>
<p>Secondary surveillance radar was an important development in the safety of aviation and remains a key element of airspace management today.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-whats-it-like-to-be-a-fighter-pilot-100563">Curious Kids: what's it like to be a fighter pilot?</a>
</strong>
</em>
</p>
<hr>
<p><em>Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to us. They can:</em></p>
<p><em>* Email your question to curiouskids@theconversation.edu.au
<br>
* Tell us on <a href="https://twitter.com/ConversationEDU">Twitter</a></em></p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/168011/original/file-20170505-21620-huq4lj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em>Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/103102/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Dowse does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Secondary radar is an important tool in the control of aircraft traffic, and helps make air travel safe. It was developed during dangerous times.
Andrew Dowse, Director, Defence Research and Engagement, Edith Cowan University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/100764
2018-07-31T06:14:17Z
2018-07-31T06:14:17Z
Lessons to learn, despite another report on missing flight MH370 and still no explanation
<p>The <a href="http://mh370.mot.gov.my/">latest report</a> into the disappearance of Malaysia Airlines flight MH370 says that investigations have failed to find any explanation as to why the aircraft went missing with 239 passengers and crew on board.</p>
<p>The 449-page main report (with <a href="http://mh370.mot.gov.my/appendix.html">additional appendices</a>) from the Malaysian government builds on previous reports on the investigation into the missing aircraft but admits it is “limited by a significant lack of evidence”. </p>
<hr>
<p><a href="https://cdn.theconversation.com/static_files/files/217/MH370SafetyInvestigationReport.pdf?1532993695">Read the report: MH370 Safety Investigation Report - Ministry of Transport Malaysia</a></p>
<hr>
<p>It’s been four years since the <a href="http://www.atsb.gov.au/mh370-pages/the-search/about-the-search/">Boeing 777-200ER went missing</a> from its routine flight between Malaysia’s capital Kuala Lumpur and China’s capital Beijing. </p>
<p>The aircraft was later found to have deviated from that flight path, with calculations showing that it probably disappeared somewhere in the Indian Ocean, off the Western Australian coast.</p>
<p>But despite an extensive search <a href="http://www.atsb.gov.au/mh370-pages/the-search/about-the-search/">led by Australia</a>, and later <a href="https://www.reuters.com/article/us-malaysia-politics-mh370-search/malaysia-says-private-search-for-mh370-to-end-next-week-idUSKCN1IO0XD">a private operator search</a>, the report says no main wreckage or bodies of the 227 passengers and 12 crew on board have ever been found.</p>
<p>Some parts identified as confirmed or almost certain to have been from the missing aircraft have been recovered, washed up around the Indian Ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=281&fit=crop&dpr=1 600w, https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=281&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=281&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=354&fit=crop&dpr=1 754w, https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=354&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/229907/original/file-20180730-102491-1dpyfl0.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=354&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Confirmed and almost certain debris identification wreckage from MH370.</span>
<span class="attribution"><a class="source" href="http://www.mot.gov.my/en/Laporan%20MH%20370/MH%20370%20Safety%20Investigation%20Report%20Slides.pdf">Ministry of Transport Malaysia</a></span>
</figcaption>
</figure>
<p>The aircraft itself has not been located, and neither the aircraft’s Flight Data Recorder (FDR) nor the Cockpit Voice Recorder (CVR) has been recovered. The only information available to the investigators was from other sources, making triangulation and validation of evidence difficult, if not impossible.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-search-for-mh370-is-over-what-we-learnt-and-where-to-now-71475">The search for MH370 is over: what we learnt and where to now</a>
</strong>
</em>
</p>
<hr>
<h2>Who’s to blame?</h2>
<p>The report notes that MH370 went missing on March 8, 2014, soon after a routine handover from the Malaysian to Vietnamese air traffic control. Communications with the aircraft were lost less than 40 minutes after takeoff.</p>
<p>Both Malaysian and Vietnamese air traffic controllers delayed initiation of emergency procedures once communication could not be established with the aircraft following the crossover from one air space to another. This, the report says, delayed any search-and-rescue response. </p>
<p>Given that the initial search area was north of the Malaysian Peninsula on the aircraft’s intended track, and any information suggesting the aircraft might have flown back over the peninsula didn’t emerge for some time, the initial delays in initiating the search-and-rescue phase may be moot.</p>
<p>The report covers several other issues related to the flight, aircraft maintenance, the crew, the cargo etc, but its conclusion ends with the line:</p>
<blockquote>
<p>…the (Investigation) Team is unable to determine the real cause for the disappearance of MH370.</p>
</blockquote>
<h2>Still a mystery</h2>
<p>Clearly, someone or something was responsible for the loss of the aircraft, passengers and crew. But without evidence from the flight recorders it’s unlikely that any of the many theories as to the cause will be proven.</p>
<p>The report suggests that from the available information and simulations, the aircraft was manually turned off the planned track, suggesting an intent on behalf of whoever was flying the aircraft. The turning off of the transponders that allow the aircraft to be tracked by civilian radars also suggests intent. </p>
<p>Hence the report goes to some lengths to suggest that unlawful interference with flight MH370 cannot be ruled out.</p>
<p>But extensive background checks of the captain and other crew found absolutely no evidence of anything other than a dedicated, professional team who set off to do their job as they had done many many times before.</p>
<p>So the causes of the tragedy are likely to remain conjecture for some considerable time, unless new evidence comes to light.</p>
<h2>No closure for the families</h2>
<p>Clearly the families of those who perished onboard MH370 will not gain much closure from this report. It contains very few answers for them. </p>
<p>But it needs to be said that the air safety investigators need data from multiple sources to try to establish with a reasonable degree of certainty the causes of crashes.</p>
<p>Aviation is a very complex socio-technical system that requires reliable analytics to fully understand the system interactions and deviations. Yet without the recorded flight data and no access to the wreckage, the ability to find cause is critically hampered.</p>
<h2>Lessons learned (and to learn)</h2>
<p>Since the loss of MH370 there has been a global push to improve tracking of airline aircraft. Clearly the travelling public want air traffic control authorities to know where all the aircraft are all of the time, without fail and without the capacity for anyone to turn the tracking system off.</p>
<p>Many in aviation would like that ideal world too. But the current tracking systems don’t have that capacity. The amount of data that would entail is well beyond the capacity of the present systems, and the cost of upgrading the systems to cope with that would be exorbitant.</p>
<p>For example, the current satellite constellation would need to be expanded or significantly enhanced. So, there has to be a compromise. </p>
<p>As the report suggests, it’s likely that improvements to the system will result in airborne aircraft “handshaking” with the tracking system every 15 minutes with GPS position, altitude, heading and speed data.</p>
<p>This should significantly improve the probability of finding an aircraft lost, but it will not guarantee a lost aircraft’s location will be known.</p>
<p>For example, if the aircraft is cruising at 350 knots (about 650kph) when it makes its last handshake with the tracking system, in 15 minutes it could be anywhere in a search area with around a 300km diameter, still representing a significant search conundrum. </p>
<p>Changes in emergency locator beacon capability are also arising from the MH370 experience. The problems with underwater signal acoustics will remain problematic. So design changes in future will likely see beacons that have the capability to detach and float to the surface if an aircraft crashes into water.</p>
<p>From the perspective of the families and from the basis of needing to understand the real lessons from MH370, ideally the search for the aircraft should continue.</p>
<p>But the real challenge is where to look. Without new data to inform a new search effort, the only thing really known is the aircraft is most likely in the Indian Ocean somewhere. That’s the message from the wreckage that has washed ashore.</p><img src="https://counter.theconversation.com/content/100764/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoffrey Dell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
A “lack of evidence” didn’t help investigators find any cause for the disappearance of Malaysia Airlines flight MH370, but a report recommends further changes to try to prevent such accidents happening again.
Geoffrey Dell, Associate Professor/Discipline Leader Accident Investigation and Forensics, CQUniversity Australia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/92330
2018-04-18T14:29:08Z
2018-04-18T14:29:08Z
Your next pilot could be drone software
<figure><img src="https://images.theconversation.com/files/212503/original/file-20180328-109193-p11abt.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5604%2C3733&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Would you be – or feel – safer if one of these people were a robot?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/flight-deck-modern-aircraft-pilots-work-389795107">Skycolors/Shutterstock.com</a></span></figcaption></figure><p>Would you get on a plane that didn’t have a human pilot in the cockpit? <a href="https://www.theguardian.com/business/2017/aug/07/air-passengers-pilotless-planes-fares-ubs/">Half of air travelers</a> surveyed in 2017 said they would not, even if the ticket was cheaper. Modern pilots do such a good job that almost any air accident is big news, such as the <a href="https://arstechnica.com/information-technology/2018/04/how-a-cracked-fan-blade-probably-ended-a-decade-of-no-us-air-travel-fatalities/">Southwest engine disintegration</a> on April 17.</p>
<p>But stories of <a href="http://www.nytimes.com/1990/08/21/us/northwest-pilots-are-found-guilty-of-drunken-flying.html">pilot drunkenness</a>, <a href="http://www.nydailynews.com/news/national/united-pilot-kicked-flight-rant-divorce-politics-article-1.2970358">rants</a>, <a href="https://www.washingtonpost.com/news/dr-gridlock/wp/2017/04/29/delta-says-pilot-who-struck-a-passenger-was-trying-to-break-up-a-fight/">fights</a> and <a href="http://abcnews.go.com/Travel/northwest-airlines-pilots-miss-airport-150-miles/story?id=8892976">distraction</a>, however rare, are reminders that pilots are only human. Not every plane can be flown by a disaster-averting pilot, like Southwest <a href="https://www.thedailybeast.com/how-veteran-fighter-pilot-tammy-jo-shults-saved-crippled-southwest-flight-1380">Capt. Tammie Jo Shults</a> or <a href="http://www.nbcnews.com/id/28678669/ns/us_news-life/t/ny-jet-crash-called-miracle-hudson/">Capt. Chesley “Sully” Sullenberger</a>. But software could change that, equipping every plane with an extremely experienced guidance system that is always learning more.</p>
<p>In fact, on many flights, autopilot systems already control the plane for <a href="https://www.cnbc.com/2015/03/26/autopilot-what-the-system-can-and-cant-do.html">basically all of the flight</a>. And software handles <a href="http://aviationweek.com/business-aviation/going-blind-zerozero-landings">the most harrowing landings</a> – when there is no visibility and the pilot can’t see anything to even know where he or she is. But human pilots are still on hand as backups.</p>
<p>A new generation of software pilots, developed for self-flying vehicles, or drones, will soon have logged more flying hours than all humans have – ever. By combining their enormous amounts of flight data and experience, drone-control software applications are poised to quickly become the world’s most experienced pilots.</p>
<h2>Drones that fly themselves</h2>
<p>Drones come in many forms, from <a href="https://www.cnet.com/news/best-toy-drones/">tiny quad-rotor copter toys</a> to <a href="http://www.af.mil/About-Us/Fact-Sheets/Display/Article/104470/mq-9-reaper/">missile-firing winged planes</a>, or even <a href="http://www.af.mil/About-Us/Fact-Sheets/Display/Article/104516/rq-4-global-hawk/">7-ton aircraft</a> that can stay aloft for 34 hours at a stretch. </p>
<p>When drones were <a href="https://www.thenation.com/article/brief-history-drones/">first introduced</a>, they were <a href="https://breakingdefense.com/2018/03/predator-started-drone-revolution-and-made-military-innovation-cool/">flown remotely</a> by human operators. However, this merely substitutes a pilot on the ground for one aloft. And it <a href="https://breakingdefense.com/2018/03/predator-started-drone-revolution-and-made-military-innovation-cool/">requires significant communications bandwidth</a> between the drone and control center, to carry real-time video from the drone and to transmit the operator’s commands. </p>
<p>Many newer drones no longer need pilots; some drones for <a href="https://www.dronezon.com/drone-reviews/drone-gps-autopilot-at-very-affordable-prices/">hobbyists and photographers</a> can now <a href="https://www.dronezon.com/drone-reviews/drone-gps-autopilot-at-very-affordable-prices/">fly themselves</a> along <a href="https://www.dronezon.com/drone-reviews/drone-gps-autopilot-at-very-affordable-prices/">human-defined routes</a>, leaving the human free to sightsee – or control the camera to get the best view.</p>
<p><a href="https://spectrum.ieee.org/automaton/robotics/drones/this-autonomous-quadrotor-swarm-doesnt-need-gps">University researchers</a>, <a href="https://www.mckinsey.com/industries/capital-projects-and-infrastructure/our-insights/commercial-drones-are-here-the-future-of-unmanned-aerial-systems">businesses</a> and <a href="https://www.nato.int/docu/review/2017/Also-in-2017/autonomous-military-drones-no-longer-science-fiction/EN/index.htm">military agencies</a> are now testing larger and more capable drones that will operate autonomously. <a href="https://www.popularmechanics.com/military/aviation/a24675/pentagon-autonomous-swarming-drones/">Swarms of drones</a> can fly without needing tens or hundreds of humans to control them. And they can perform <a href="https://www.cbsnews.com/news/60-minutes-autonomous-drones-set-to-revolutionize-military-technology/">coordinated maneuvers</a> that human controllers could never handle.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/waeXQwnkYAc?wmode=transparent&start=121" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Could humans control these 1,218 drones all together?</span></figcaption>
</figure>
<p>Whether flying in swarms or alone, the software that controls these drones is rapidly gaining flight experience. </p>
<h2>Importance of pilot experience</h2>
<p>Experience is the main qualification for pilots. Even a person who wants to fly a small plane for personal and noncommercial use needs <a href="https://www.firstflight.com/private-pilot-requirements/">40 hours</a> of flying instruction before getting a private pilot’s license. Commercial airline pilots must have <a href="https://www.flyingmag.com/training/getting-your-atp-certificate">at least 1,000 hours</a> before even serving as a co-pilot. </p>
<p>On-the-ground training and in-flight experience prepare pilots for unusual and emergency scenarios, ideally to help save lives in situations like the “<a href="http://www.nbcnews.com/id/28678669/ns/us_news-life/t/ny-jet-crash-called-miracle-hudson/">Miracle on the Hudson</a>.” But many pilots are less experienced than “Sully” Sullenberger, who saved his planeload of people with quick and creative thinking. With software, though, every plane can have on board a pilot with as much experience – if not more. A popular software pilot system, in use in many aircraft at once, could gain more flight time each day than a single human might <a href="https://www.ecfr.gov/cgi-bin/text-idx?SID=1e483077c0bff7e356d8aece28712f40&node=14:3.0.1.1.7.17.3.2&rgn=div8">accumulate in a year</a>. </p>
<p>As someone who studies <a href="https://doi.org/10.1016/j.techsoc.2013.12.004">technology policy</a> as well as the use of artificial intelligence for <a href="https://doi.org/10.1109/AERO.2016.7500814">drones</a>, <a href="https://doi.org/10.1109/SYSOSE.2017.7994957">cars</a>, <a href="https://doi.org/10.1080/0952813X.2015.1020569">robots</a> and other uses, I don’t lightly suggest handing over the controls for those additional tasks. But giving software pilots more control would maximize computers’ advantages over humans in training, testing and reliability.</p>
<h2>Training and testing software pilots</h2>
<p>Unlike people, computers will follow sets of instructions in software the same way every time. That lets developers create instructions, test reactions and refine aircraft responses. Testing could make it far less likely, for example, that a computer would <a href="https://www.cnn.com/2012/04/17/travel/canada-disoriented-pilot/index.html">mistake the planet Venus for an oncoming jet</a> and throw the plane into a steep dive to avoid it. </p>
<p>The most significant advantage is scale: Rather than teaching thousands of individual pilots new skills, updating thousands of aircraft would require only downloading updated software.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=457&fit=crop&dpr=1 600w, https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=457&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=457&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/212492/original/file-20180328-109169-eq9rxd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">US Airways Flight 1549 passengers evacuate in the water after an emergency landing.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Miracle-on-the-Hudson-Bird-Strikes/876999a8e670497ca7299e9d137c9109/1/0">AP Photo/Bebeto Matthews</a></span>
</figcaption>
</figure>
<p>These systems would also need to be thoroughly tested – in both real-life situations and in <a href="http://mdpi.com/2073-431X/2/2/67">simulations</a> – to handle a wide range of aviation situations and to <a href="https://theconversation.com/can-you-be-hacked-by-the-world-around-you-83195">withstand cyberattacks</a>. But once they’re working well, software pilots are not susceptible to distraction, disorientation, fatigue or other human impairments that can create problems or cause errors even in common situations.</p>
<h2>Rapid response and adaptation</h2>
<p>Already, aircraft regulators are concerned that human pilots are <a href="https://www.popularmechanics.com/flight/a18951/department-of-transportation-report-pilots-are-forgetting-how-to-fly-manually/">forgetting how to fly</a> on their own and may have trouble taking over from an autopilot in an emergency.</p>
<p>In the “<a href="http://www.nbcnews.com/id/28678669/ns/us_news-life/t/ny-jet-crash-called-miracle-hudson/">Miracle on the Hudson</a>” event, for example, a key factor in what happened was <a href="https://www.cbsnews.com/news/ntsb-sully-could-have-made-it-back-to-laguardia/">how long it took for the human pilots to figure out what had happened</a> – that the plane had flown through a flock of birds, which had damaged both engines – and how to respond. Rather than the <a href="https://www.telegraph.co.uk/films/sully/miracle-on-the-hudson-how-it-happened/">approximately one minute</a> it took the humans, a computer could have assessed the situation in seconds, potentially saving enough time that the plane could have landed on a runway instead of a river.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/212493/original/file-20180328-109190-1vmv8y0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">At the NTSB hearing, investigators learned how the decision time made it impossible for Flight 1549 to return to the airport, forcing the water landing.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Plane-Splashdown-Hearing/263dbf7af6f24c98bd3b973dd59e68da/1/0">AP Photo/Charles Dharapak</a></span>
</figcaption>
</figure>
<p>Aircraft damage can pose another particularly difficult challenge for human pilots: It can change what effects the controls have on its flight. In cases where damage <a href="http://bismarcktribune.com/news/state-and-regional/und-plane-crashed-after-hitting-goose/article_07e9494c-3719-5cd6-84ac-84a72d575a2e.html">renders a plane uncontrollable</a>, the result is often tragedy. A sufficiently advanced automated system could make minute changes to the aircraft’s steering and use its sensors to quickly evaluate the effects of those movements – essentially learning how to fly all over again with a damaged plane.</p>
<h2>Boosting public confidence</h2>
<p>The biggest barrier to fully automated flight is psychological, not technical. Many people may not want to trust their lives to computer systems. But they might come around when reassured that the software pilot has tens, hundreds or thousands more hours of flight experience than any human pilot.</p>
<p>Other autonomous technologies, too, are progressing despite public concerns. Regulators and lawmakers are <a href="http://www.ncsl.org/research/transportation/autonomous-vehicles-self-driving-vehicles-enacted-legislation.aspx">allowing self-driving cars on the roads</a> in many states. But more than half of Americans <a href="https://theconversation.com/to-get-the-most-out-of-self-driving-cars-tap-the-brakes-on-their-rollout-88444">don’t want to ride in one</a>, largely because they <a href="http://www.pewinternet.org/2017/10/04/americans-attitudes-toward-driverless-vehicles/">don’t trust the technology</a>. And only <a href="http://money.cnn.com/2017/08/07/technology/business/pilotless-planes-passengers/index.html">17 percent of travelers</a> around the world are willing to board a plane without a pilot. However, as more people experience self-driving cars on the road and have <a href="https://www.amazon.com/Amazon-Prime-Air/b?ie=UTF8&node=8037720011">drones deliver them packages</a>, it is likely that software pilots will gain in acceptance.</p>
<p><a href="http://www.pewinternet.org/2017/10/04/automation-in-everyday-life/pi_2017-10-04_automation_3-05/"><img width="420" height="671" src="http://assets.pewresearch.org/wp-content/uploads/sites/14/2017/10/03102012/PI_2017.10.04_Automation_3-05.png" class="attachment-large size-large" alt="Slight majority of Americans would not want to ride in a driverless vehicle if given the chance; safety concerns, lack of trust lead their list of concerns"></a></p>
<p>The airline industry will certainly be pushing people to trust the new systems: Automating pilots could <a href="http://money.cnn.com/2017/08/07/technology/business/pilotless-planes-passengers/index.html">save tens of billions of dollars</a> a year. And the current <a href="http://www.grandforksherald.com/news/4422547-us-pilot-shortage-reaching-crisis-fargo-travelers-it-means-fewer-flights-destinations">pilot shortage</a> means software pilots may be the key to having any airline service to smaller destinations. </p>
<p>Both <a href="http://money.cnn.com/2017/10/05/news/companies/boeing-acquires-aurora-autonomous-797-air-taxi/index.html">Boeing</a> and <a href="http://www.independent.co.uk/news/business/news/airbus-pilotless-planes-self-flying-aircraft-passenger-flights-cto-paul-eremenko-a8068956.html">Airbus</a> have made significant investments in automated flight technology, which would remove or reduce the need for human pilots. Boeing has actually bought a drone manufacturer and is <a href="http://money.cnn.com/2017/10/05/news/companies/boeing-acquires-aurora-autonomous-797-air-taxi/index.html">looking to add software pilot capabilities</a> to the next generation of its passenger aircraft. (Other tests have tried to <a href="https://phys.org/news/2016-10-cockpit-robot.html">retrofit existing aircraft</a> with robotic pilots.)</p>
<p>One way to help regular passengers become comfortable with software pilots – while also helping to both train and test the systems – could be to introduce them as co-pilots working alongside human pilots. Planes would be operated by software from gate to gate, with the pilots instructed to touch the controls only if the system fails. Eventually pilots could be removed from the aircraft altogether, just like they eventually were from the <a href="https://motherboard.vice.com/en_us/article/wnj75z/why-dont-we-have-driverless-trains-yet">driverless trains</a> that we routinely ride in airports around the world.</p><img src="https://counter.theconversation.com/content/92330/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeremy Straub is the associate director of the NDSU Institute for Cyber Security Education and Research. He has received funding related to AI and robotics from the North Dakota State University, the NDSU Foundation and Alumni Association, the U.S. National Science Foundation, the University of North Dakota and Sigma Xi. He is the lead inventor on a patent-pending technology for autonomous control of robots, UAVs and spacecraft. The views presented are his own and do not necessarily represent the views of NDSU or funding agencies.</span></em></p>
Airplanes could be safer with technology at the helm. A key sticking point is human opinion.
Jeremy Straub, Assistant Professor of Computer Science, North Dakota State University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/85981
2017-10-26T01:40:47Z
2017-10-26T01:40:47Z
In for the long-haul: the challenge to fly non-stop from Australia to anywhere in the world
<p>Australian airline Qantas has <a href="http://www.perthnow.com.au/news/western-australia/inside-the-new-qantas-dreamliner-that-will-fly-perthlondon-nonstop/news-story/2e1335cc7f63c3003d60df5d4e371550">the aircraft it needs</a> to fly non-stop from Perth to London, but its goal is to offer even longer flights than that.</p>
<p>The airline’s chief executive Alan Joyce has <a href="http://www.smh.com.au/business/aviation/qantas-closes-in-on-dream-of-ultralonghaul-direct-flights-20171016-gz1lb6.html">asked manufacturers</a> to build an aircraft that can fly non-stop from Australia’s east coast capitals to London. His eyes are also on non-stop flights to New York, Brazil and South Africa.</p>
<p>So what will it take to make such long-haul flights possible?</p>
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<strong>
Read more:
<a href="https://theconversation.com/inflight-wi-fi-highlights-challenges-of-satellite-broadband-delivery-on-land-and-in-the-sky-75381">Inflight Wi-Fi highlights challenges of satellite broadband delivery on land and in the sky</a>
</strong>
</em>
</p>
<hr>
<h2>The technology’s nearly ready</h2>
<p>Advances in technology have enabled aircraft to be lighter and consume less fuel. </p>
<p>For example, the maker of the new <a href="http://www.aircraft.airbus.com/aircraftfamilies/passengeraircraft/a350xwbfamily/">Airbus A350</a> says the aircraft has some significant new features. These include a wing with improved lift-to-drag characteristics, more fuel-efficient Trent XWB engines, a lighter air conditioning electrical system, and more integrated aviation electronics.</p>
<p>The reduced weight and modified fuel system increase fuel carrying capacity from <a href="http://www.aircraft.airbus.com/aircraftfamilies/passengeraircraft/a350xwbfamily/a350-900/">141,000 litres to 165,000 litres</a>, giving the plane a range of at least <a href="http://www.aircraft.airbus.com/aircraftfamilies/passengeraircraft/a350xwbfamily/a350-800/">15,270km</a>. </p>
<p>That’s still short of the distance from Sydney to London, which is about 17,000km. But <a href="http://www.reuters.com/article/us-qantas-orders/airbus-boeing-close-in-on-qantas-ultra-long-haul-dream-idUSKBN1772X3">reports say Airbus’s</a> new Ultra-Long Range version of the A350 will have a range of 17,960km, meaning that Joyce could potentially meet his challenge.</p>
<p><iframe id="hqRMp" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/hqRMp/3/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Destination hubs</h2>
<p>But what is pushing airlines to want to fly longer long-haul?</p>
<p>Airlines such as Qantas, United Airlines, British Airways, Singapore Airlines and Emirates operate on a hub-and-spoke network strategy. This allows them to feed passengers into a single home-based airport (the hub), before redistributing them to various destinations (the spokes). </p>
<p>This has led to the emergence of fortress hubs such as Sydney for Qantas, Los Angeles for United Airlines, London Heathrow for British Airways, Singapore for Singapore Airlines, and Dubai for Emirates.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191765/original/file-20171025-5855-8iaw7o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dubai is one of the world’s busiest airports.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/hisgett/31370233344/">Flickr/Tony Hisgett</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>From an airline’s perspective, a hub airport in its home country needs to be protected aggressively to maintain its competitive edge.</p>
<p>Until the early 2000s, aviation technology only allowed airlines to fly short- or medium-haul spokes to feed its hub traffic, such as Athens to London (4 hours), Darwin to Sydney (4h 20m), and Moscow to Dubai (5h 20m). Regulatory constraints also prevented airlines from carrying international traffic to feed its home hub. </p>
<p>But airline liberalisation and technology advancements now allow airlines to operate long-haul spokes, thus strengthening their home hubs. Examples include China Southern’s flight from Perth to Guangzhou (8h), Air China’s Melbourne to Beijing (11h 20m), and Emirates’ Glasgow to Dubai (7h 55m).</p>
<p>Emirates is a pioneer in stretching this hub-and-long-haul spoke system by flying from Dubai into international airports such as Johannesburg (8h 10m) and Perth (11h).</p>
<p>As a result, Emirates has built its Dubai hub into one of the world’s busiest airports, undermining rivals such as London Heathrow, Singapore and Sydney.</p>
<p>It is not surprising that other airlines want to join the race to launch long-hauls.</p>
<h2>Passenger endurance</h2>
<p>From a traveller’s perspective, flying directly to your final destination will certainly save the transit hassles at a congested hub, and reduce the risk of missing your connecting flight.</p>
<p>But are you prepared to cram yourself into an economy seat for 17-20 hours?</p>
<p>Although you can probably enjoy movies back-to-back, how will your body cope? Several factors are responsible for comfort on a long-haul flight, including internal cabin pressure, cabin humidity, and legroom.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191764/original/file-20171025-5838-1wwooc4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Only so many movies you can watch on a flight.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dgmckelvey/8993433842/">Flickr/David McKelvey</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Internal cabin pressure is probably the most important factor. Carbon-fibre-reinforced composites used in both the Boeing 787 Dreamliner and Airbus A350-900ULR allow a higher cabin humidity, thus increasing comfort.</p>
<p>But you need to be mindful of some <a href="http://www.independent.co.uk/travel/news-and-advice/worlds-longest-flight-body-effects-health-dvt-air-recirculation-a7517661.html">high-altitude physiology</a> such as ear popping, sore teeth, dry skin, dry eyes, and dehydration. </p>
<p>There is also a risk of developing Deep Vein Thrombosis (<a href="https://www.healthdirect.gov.au/deep-vein-thrombosis">DVT</a>), especially among people with a family history of the condition. </p>
<p>Then there is the hazard of timezone-related circadian rhythm (body clock) disruption. Jet lag affects your whole physiology, and you might need <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/jet-lag">a few days to recover</a> after a particularly long flight.</p>
<h2>Pilots and crew</h2>
<p>Pilots and cabin crew face the same, if not more, challenges as passengers onboard a long-haul flight. Flying a sophisticated aircraft requires a great deal of concentration, discipline and experience, and pilots need to be well rested and alert.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191766/original/file-20171025-5822-fsd8di.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Regulations are in place to help prevent fatigue in pilots.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/jurvetson/7510460530/">Flickr/Steve Jurvetson</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The International Civil Aviation Organization <a href="https://www.icao.int/safety/airnavigation/OPS/CabinSafety/Pages/Cabin-Crew-Fatigue-Management.aspx">says fatigue</a> can impair the alertness of crew and their ability to safely operate an aircraft or perform safety-related duties.</p>
<p>The American Aerospace Medical Association <a href="http://dx.doi.org/10.3357/ASEM.2435.2009">has also warned</a> that ultra-long-range operations may exacerbate pilots’ fatigue levels that have already been shown to impair safety, alertness and performance in existing flight operations.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/friday-essay-smile-and-stay-thin-life-as-a-60s-air-hostess-77102">Friday essay: smile and stay thin – life as a 60s air hostess</a>
</strong>
</em>
</p>
<hr>
<p>The good news is that aviation safety regulators such as the Civil Aviation Safety Authority in Australia, the US Federal Aviation Administration, and the European Aviation Safety Agency have all introduced fatigue-management rules for commercial pilots.</p>
<p>These authorities review the rules regularly and hold airlines responsible for their pilots fatigue management to ensure safe operation. </p>
<p>Airlines also have safety mechanisms in place with pilots and cabin crews educated and trained continuously and regularly on fatigue management. </p>
<p>For a long-haul flight, two full cockpit crews are typically deployed to allow crews to take turns to rest. Some airlines are quite tolerant of pilots who call in sick if they are fatigued.</p>
<p>So the ultimate challenge for any longer long-haul flight is not operational or technological. As Alan Epstein, vice-president for technology American aerospace manufacturer Pratt & Whitney, <a href="https://www.ft.com/content/689a1618-814d-11e5-8095-ed1a37d1e096">put it</a>: “The limit is no longer the endurance of the engines. It is the endurance of passengers.”</p><img src="https://counter.theconversation.com/content/85981/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chrystal Zhang does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Airlines want to stretch their routes even longer with non-stop flights to almost anywhere in the world.
Chrystal Zhang, Senior Lecturer in Aviation, Swinburne University of Technology
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/80795
2017-08-03T00:59:51Z
2017-08-03T00:59:51Z
How hot weather – and climate change – affect airline flights
<figure><img src="https://images.theconversation.com/files/180077/original/file-20170727-8486-3gcmgf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">When is it too hot to fly?</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/heat-wave-airplane-airport-665107561">Dmitri Fedorov/Shutterstock.com</a></span></figcaption></figure><p>Hot weather has forced <a href="https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/06/20/its-so-hot-in-phoenix-that-airplanes-cant-fly/">dozens of commercial flights to be canceled</a> at airports in the Southwest this summer. This flight-disrupting heat is a warning sign. Climate change is projected to have far-reaching repercussions – including <a href="http://dx.doi.org/10.1098/rsta.2012.0294">sea level rise inundating cities</a> and shifting weather patterns causing <a href="http://dx.doi.org/10.1073/pnas.0906865106">long-term declines in agricultural yields</a>. And there is evidence that it is beginning to affect the takeoff performance of commercial aircraft, with potential effects on airline costs.</p>
<p>National and global transportation systems and the economic activity they support have been <a href="http://dx.doi.org/10.1038/nature15725">optimized for the climate</a> in which it all developed: Machines are designed to operate in common temperature ranges, logistical plans depend on historical weather patterns and coastal land development is based on <a href="http://cpo.noaa.gov/sites/cpo/Reports/2012/NOAA_SLR_r3.pdf">known flood zones</a>. In the aviation sector, airports and aircraft are designed for the weather conditions experienced historically. Because the climate is changing, even fundamental infrastructure elements like airports and key economic sectors like air transportation may need to be redesigned and reengineered.</p>
<p>As scientists focused on the <a href="http://dx.doi.org/10.1175/WCAS-D-15-0063.1">impacts of climate change and extreme weather</a> on human society and natural ecosystems around the world, our research has quantified how extreme heat associated with our <a href="http://dx.doi.org/10.1007/s10584-017-2018-9">warming climate may affect flights</a> around the world. We’ve found that major airports from New York to Dubai to Bangkok will see more frequent takeoff weight restrictions in the coming decades due to increasingly common hot temperatures.</p>
<h2>Climate changes flights</h2>
<p>There is robust evidence that extreme events such as heat waves and coastal flooding are happening with <a href="http://dx.doi.org/10.1073/pnas.1222469111">greater frequency and intensity</a> than just a few decades ago. And if we fail to reduce greenhouse gas emissions significantly in the next few decades, the frequency and intensity of these extremes is projected to <a href="http://dx.doi.org/10.1002/jgrd.50188">increase dramatically</a>. </p>
<p>The effects on aviation may be widespread. Many airports are built near sea level, putting them <a href="https://doi.org/10.1016/j.trpro.2016.05.036">at risk of more frequent flooding</a> as oceans rise. The frequency and intensity of <a href="http://dx.doi.org/10.1038/nclimate1866">air turbulence may increase</a> in some regions due to <a href="http://dx.doi.org/10.1007/s00376-017-6268-2">strengthening high-altitude winds</a>. Stronger winds would force airlines and pilots to <a href="https://doi.org/10.1088/1748-9326/11/2/024008">modify flight lengths and routings</a>, potentially increasing fuel consumption. </p>
<p>The July heat-related <a href="https://www.circa.com/story/2017/06/20/nation/american-airlines-canceled-flights-in-phoenix-because-its-too-hot-for-planes-to-fly">Phoenix flight cancellations</a> happened at least in part because airlines’ operational manuals didn’t include information for <a href="http://www.fox10phoenix.com/news/arizona-news/262509476-story">temperatures above 118 degrees Fahrenheit</a> – because that kind of heat is historically uncommon. It’s another example of how procedures may need to be updated to adapt to a warmer climate.</p>
<h2>Flying in the heat</h2>
<p>High air temperatures affect the physics of how aircraft fly, meaning aircraft takeoff performance can be <a href="https://doi.org/10.1175/WCAS-D-14-00026.1">impaired on hot days</a>. The amount of lift that an airplane wing generates is affected by the density of the air. Air density in turn depends mostly on air temperature and elevation; higher temperatures and higher elevations both reduce density. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=874&fit=crop&dpr=1 600w, https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=874&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=874&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1098&fit=crop&dpr=1 754w, https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1098&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/179073/original/file-20170720-1588-51jqbs.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1098&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hot air is less dense than cooler air. That affects the amount of lift an airplane can generate.</span>
<span class="attribution"><span class="source">The Conversation (via Piktochart)</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The lower the air density, the faster an airplane must travel to produce enough lift to take off. It takes more runway to reach a higher speed, and depending on how long the airport’s runway is, some airplanes might risk running out of room before reaching sufficient speed. When this occurs, the only immediate option is to reduce the aircraft’s weight to lower its required takeoff speed – by removing passengers, luggage and cargo. This is referred to as a weight restriction. </p>
<p>Weight restrictions happen now, especially in hot places like Phoenix and <a href="http://www.ldeo.columbia.edu/news-events/surging-heat-may-limit-aircraft-takeoffs-globally">Dubai</a> and at airports with short runways like <a href="https://www.wsj.com/articles/la-guardias-runways-come-up-short-1479078957">New York’s LaGuardia</a> and Washington, D.C.’s Reagan National, but our research suggests that they may become much more common in the future. </p>
<p>Global temperatures have been <a href="https://www.ipcc.ch/report/ar5/wg1/">steadily rising for decades</a>, and they will almost certainly continue to do so. In some regions, there is evidence that the <a href="http://dx.doi.org/10.1002/2015GL064914">hottest temperatures may increase at a faster rate</a> than the average, <a href="http://dx.doi.org/10.1007/s40641-016-0042-x">further stacking the deck</a> in favor of extreme heat. These hotter temperatures will reduce air density and make it much more likely weight restrictions are needed for flights taking off during the hottest parts of the day. </p>
<p>The frequency and magnitude of weight restrictions is projected to increase – in some locations, the number of days requiring at least some amount of weight restriction for certain aircraft could double or triple, perhaps covering 50 or more days per year.</p>
<h2>The economics of adaptation</h2>
<p>On most affected flights, the amount of cargo, passengers and fuel that must be removed to allow for takeoff will usually be small – between 0.5 percent and 4 percent of the total load. That means fewer paying customers on airplanes, and less cargo on board. When those restrictions add up across the global air transport system, the costs can be significant.</p>
<p>Carrying just a fraction of a percent fewer passengers or less cargo can add up to <a href="https://www.wired.com/2012/09/how-can-airlines-reduce-fuel-costs/">millions of dollars in lost revenue</a> for an airline over years of operation. That makes even small weight restrictions a concern in such a highly competitive and optimized industry. These limits could disproportionately affect <a href="https://www.ft.com/content/689a1618-814d-11e5-8095-ed1a37d1e096">long-haul flights</a>, which require large fuel loads and often take off near their maximum weights.</p>
<p>There are ways that airlines could mitigate increasing weight restrictions. The most feasible is to reschedule some flights to cooler hours of the day – although with <a href="http://www.iata.org/pressroom/pr/Pages/2016-10-18-02.aspx">air traffic increasing</a> and many airports already <a href="http://www.accessmagazine.org/spring-2016/manage-flight-demand-or-build-airport-capacity/">operating near capacity</a>, this could prove difficult. </p>
<p>Another potential solution is to build longer runways. But that’s not always possible: Some airports, like New York’s LaGuardia, are on coastlines or in dense urban environments. Even where a longer runway is technically possible, buying the land and expanding an airport’s physical area may be <a href="http://www.bbc.com/news/business-35011620">expensive and politically difficult</a>.</p>
<p>Aircraft could be optimized for takeoff performance, but redesigning aircraft is <a href="http://www.seattletimes.com/business/boeing-aerospace/will-787-program-ever-show-an-overall-profit-analysts-grow-more-skeptical/">extremely expensive and can take decades</a>. <a href="http://www.boeing.com/features/2016/01/innovation-777-lighter-01-16.page">Manufacturers are always working</a> to build planes that are <a href="https://www.wired.com/2015/06/planes-get-efficient-heres/">lighter and more fuel-efficient</a>. In the future, those efficiency improvements will be necessary just to maintain today’s performance.</p>
<h2>Broader implications</h2>
<p>These changes are merely examples of the countless procedures, processes and equipment requirements that will have to be adjusted for a changing climate. Even if those adaptations are successful, they will take effort and money to achieve.</p>
<p>Many sectors of the economy, including the aviation industry, have yet to seriously consider the effects of climate change. The sooner, the better: Both airport construction and aircraft design take decades, and have lasting effects. Today’s newest planes may well be <a href="http://www.airspacemag.com/need-to-know/what-determines-an-airplanes-lifespan-29533465/">flying in 40 or 50 years</a>, and their replacements are being designed now. The earlier climate impacts are understood and appreciated, the more effective and less costly adaptations can be. Those adaptations may even include innovative ways to dramatically reduce climate-altering emissions across the aviation sector, which would help reduce the problem while also responding to it.</p><img src="https://counter.theconversation.com/content/80795/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
Major airports around the world will see more frequent flight restrictions in the coming decades because of increasingly common hot temperatures.
Ethan D. Coffel, Ph.D. Student in Earth & Environmental Sciences, Columbia University
Radley Horton, Associate Research Scientist, Center for Climate Systems Research, Columbia University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/75076
2017-03-23T17:00:53Z
2017-03-23T17:00:53Z
Banning laptops at secure airports won’t keep aircraft safe from terror attacks
<figure><img src="https://images.theconversation.com/files/162211/original/image-20170323-4965-1ivg61p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Introducing new security measures for the airline industry is rarely done lightly by governments. Certainly it’s underpinned by the responsibility to ensure passenger safety. But it’s not clear how effective the recent ban on laptops and large electronic devices in aircraft cabin baggage on flights from certain Middle Eastern airports to the US and UK will be.</p>
<p>There is evidence that airport baggage scanners in many developing world airports aren’t sophisticated enough to detect the latest explosive devices that can be hidden in electronic devices. But limiting the restrictions to just ten specific airports leaves open significant other risks that could be exploited.</p>
<p>The laptop ban is reportedly due to “evaluated intelligence” about attempts to smuggle explosive devices in <a href="https://www.dhs.gov/news/2017/03/21/qa-aviation-security-enhancements-select-last-point-departure-airports-commercial">various consumer items</a>. This is almost certainly linked to the attack on the Daallo Airlines Flight from Mogadishu, Somalia in February 2016, when an explosive device hidden in a laptop was <a href="http://www.bbc.co.uk/news/world-africa-35521646">detonated shortly after take-off</a>.</p>
<p>Since this incident, there has been concern that the bomb-making capabilities of terrorist groups such as Al-Shabaab, ISIS and Al-Qaeda may have become sophisticated enough to <a href="https://www.ctc.usma.edu/posts/the-evolving-challenges-for-explosive-detection-in-the-aviation-sector-and-beyond">bypass airport X-ray machines</a>.</p>
<p>However, CNN terror analyst <a href="https://www.ctc.usma.edu/posts/the-evolving-challenges-for-explosive-detection-in-the-aviation-sector-and-beyond">Paul Cruikshank has argued</a> that the “layered state-of-the-art detection systems that are now in place at most airports in the developed world make it very hard for terrorists to sneak bombs onto planes”. He believes that, due to the levels of technology in place, it is unlikely that any explosive device would go undetected in the screening process used in many international airports.</p>
<p>But security threats must still be addressed and, given that many airports in the developing world do not have this level of screening, there is no doubt that banning electronic devices from the cabin goes some way towards addressing this threat. Yet perhaps the ban implemented across ten airports, including major hubs in Doha, Istanbul and Dubai (which has the world’s third busiest airport), does not go far enough.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/162213/original/image-20170323-4938-8ent8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Nowhere to hide … with the right equipment.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<p>Only outbound direct flights to the US and UK run by specifically named airline operators are bound by the restrictions. All the airports on the list are in countries that are either at risk from terrorism or are seen as a particular focus of terrorist activity.</p>
<p>But a number of the above airports operate the highly sophisticated state-of-the-art detection systems that Cruikshank refers to. If the ban is implemented at these airports, then what of those many airports in the developing world which do not have state-of-the-art machines, or benefit from highly qualified staff? And the threat of terrorism exists in other parts of the Middle East, Africa and Asia, where there is support for Al Qaeda, ISIS and other terrorist networks.</p>
<p>We also need to consider potential terrorist behaviour. We can’t ignore the fact that terrorists may simply take an alternative route to the US or UK that isn’t subject to these restrictions. In this case, the vulnerability just shifts somewhere else.</p>
<h2>Unresolved risks</h2>
<p>It would also be very naïve to assume that simply forcing customers to pack their electronic devices into hold baggage would be safer than taking them in the cabin. If a bomb would go undetected in carry-on luggage, there is a strong chance it wouldn’t be found if it were <a href="https://www.asi-mag.com/cargo-screening-technological-options/">screened for the cargo hold</a>. </p>
<p>Another key security risk area is not just the technology used in airports but the vulnerabilities within it. If terrorist groups are intent on attacks on aircraft, they can do so from any airport in the world by recruiting sympathisers <a href="http://link.springer.com/journal/12198/7/4/page/1">among airport staff</a>. As happened during the Somali attack <a href="https://www.theguardian.com/world/2016/feb/08/somalia-plane-blast-airport-worker-handed-device-to-bombing-suspect">last year</a>, some airports may place their staff under less scrutiny than others, allowing access to restricted areas where devices could be placed on aircraft.</p>
<p>There is no doubt that terrorists will continually try and find ways to avert detection and bypass security. But shifting the vulnerability is not the solution. Only by the whole of the international aviation industry working together will the threat be minimised.</p><img src="https://counter.theconversation.com/content/75076/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michaela Preddy does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The ban on electronic devices in cabin luggage overlooks the airports that would be least likely to detect a bomb.
Michaela Preddy, Lecturer in Airport Security Management and Policing, School of Forensic and Applied Sciences, University of Central Lancashire
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/73554
2017-02-27T16:56:16Z
2017-02-27T16:56:16Z
Stop blaming pilots for aircraft crashes – bypassing the rules can save lives
<figure><img src="https://images.theconversation.com/files/158313/original/image-20170224-23038-g9gn1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Courtesy of Warner Bros. Pictures</span></span></figcaption></figure><p>The denouement of the recent Hollywood blockbuster Sully is a courtroom drama with a difference. On trial is the eponymous Captain Chesley Sullenberger (Sully), based on the real pilot who saved the lives of 155 passengers and crew by successfully landing his plane on the river Hudson in January 2009 after a bird hit stalled both engines.</p>
<p>Sully (played by Tom Hanks) faces an air crash investigation committee. But why was a man widely recognised as an all-American hero, whose quick thinking prevented a major airline disaster, facing punishment for his actions?</p>
<p>Every major aviation incident is followed by a full investigation, with the aim of fixing responsibility and making recommendations for prevention in the future. Research shows that in more than 80% of cases, human error by pilots is found to have played at least <a href="https://books.google.co.uk/books?hl=en&lr=&id=28B3o2RRY9sC&oi=fnd&pg=PT11&dq=human+error+80%25&ots=Nf9EimoZoB&sig=-t5FSux7OAwqPm2VmLf3mKJCFQY#v=onepage&q=human%20error%2080%25&f=false">some part in the mishap</a>. </p>
<p>This narrative of finding blame in the actions of individual pilots is portrayed quite well in Sully. But it has also been challenged in recent times by those thinkers who argue we should look at the word as a series of complex systems.</p>
<p>In the film, the investigators argue that Sully had risked lives by not turning the aeroplane around and making a potentially safer and far more comfortable landing at La Guardia airport. But Captain Sully destroys their arguments by asking the crash investigators to place themselves in the reality of the situation.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=316&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=316&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=316&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=397&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=397&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158341/original/image-20170224-22986-quh98c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=397&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Safety on trial.</span>
<span class="attribution"><span class="source">Courtesy of Warner Bros. Pictures</span></span>
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</figure>
<p>He successfully demonstrates that, given the stress under which he operated and the reaction time of the human brain in an emergency, there was no possibility that he could have glided the plane back to the airport. The computer simulations of the incident had failed to take these factors into account and so they, and not the human pilot, were wrong.</p>
<p>There <a href="https://qz.com/778011/sully-ntsb-investigators-are-not-happy-about-being-made-the-villains-in-clint-eastwoods-film-starring-tom-hanks-as-chesley-sully-sullenberger/">has been controversy</a> over the veracity of the story depicted by the film. Nevertheless, the director did a good job of popularising key concepts in air crash investigations that have now been recognised widely by complex systems theorists as basic flaws in the process. Research by academics like Sydney Dekker, Eric Hollnagel and James Rasmussen has pointed to the inability of investigators to fully appreciate the <a href="https://books.google.co.uk/books?hl=en&lr=&id=IRAcBgAAQBAJ&oi=fnd&pg=PR7&dq=human+error+dekker&ots=8a-kwGNT3v&sig=CCbIydcGbQOqPNrGY-GtQcChuS8#v=onepage&q=human%20error%20dekker&f=false">conditions in which airline pilots take critical decisions during emergencies</a>.</p>
<p>Nor do investigations account for the stress under which pilots operate and the pressure upon them to think creatively and deviate from standard procedures in order to save lives.</p>
<h2>Biased judgement</h2>
<p><a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.474.3161&rep=rep1&type=pdf">Research has also shown</a> that crash investigators suffer from two kinds of biases that stem from judging an incident that has already occurred. The facts of the case can seem far simpler with the passage of time than they were to the pilot in the heat of the moment.</p>
<p>The “outcome bias” is the tendency of the investigators to label the same set of actions by a pilot as an error when there is a mishap. Whereas, in typical circumstances, the actions would have otherwise been passed off as normal. Similarly, the “hindsight bias” makes the investigators attribute far more mental and physical capacity to the pilots to handle an emergency than is humanly possible at the time. </p>
<p>The argument isn’t that pilots don’t make mistakes, or that their failure to follow procedure isn’t a factor in the subsequent accidents. But in complex systems we should recognise that pilots involved in accidents aren’t necessarily bad apples. It is similar to the way we often blame crimes solely on individuals when there are also <a href="https://crimesciencejournal.springeropen.com/articles/10.1186/2193-7680-1-3">situational factors</a> at work that encourage rule-breaking.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=316&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=316&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=316&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=397&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=397&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158343/original/image-20170224-23004-1aq87r1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=397&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Quick thinking.</span>
<span class="attribution"><span class="source">Courtesy of Warner Bros. Pictures</span></span>
</figcaption>
</figure>
<p>Pilots who are involved in mishaps are not necessarily bad at their jobs. Instead, they often use their past experience to bypass rules, and indulge in a rational decision-making process (however flawed) to respond to an emergency that is a sudden, novel and stressful situation for them.</p>
<p>The way forward for air crash investigators is to study how airline pilots operate in normal working conditions. This approach is currently being considered in the study of standard operating procedures <a href="http://link.springer.com/article/10.1007/s40864-017-0050-8">used by train drivers</a>.</p>
<p>Investigators need to appreciate the stress pilots find themselves under, and how they regularly deviate from standard procedures to fly the plane safely in a dynamic work environment. A more realistic understanding of how pilots work will help develop more representative computer simulations and more effective recommendations to prevent accidents in the future.</p>
<p>An interesting question to raise at this point would be: what would have happened if the landing on river Hudson had ended in disaster for Captain Sully? Probably the investigation would have concluded that he had enough time to return to the airport, and his derring-do to go for the river had cost 155 lives. Clint Eastwood wouldn’t have made it into a movie, that’s for sure.</p><img src="https://counter.theconversation.com/content/73554/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kartikeya Tripathi has received funding from Engineering and Physical Sciences Research Council (EPSRC) and University College London (UCL) in the UK. </span></em></p><p class="fine-print"><em><span>Hervé Borrion has received funding from Engineering and Physical Sciences Research Council (EPSRC) and the European Commission.</span></em></p>
The recent film Sully reveals just what pilots are facing in a disaster situation.
Kartikeya Tripathi, Teaching Fellow, Security and Crime Science, UCL
Hervé Borrion, Senior Lecturer in Security and Crime Science, UCL
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/69595
2016-11-30T06:43:36Z
2016-11-30T06:43:36Z
Colombia plane crash: how can people survive deadly air disasters?
<p>A plane crash in Colombia has <a href="http://www.bbc.co.uk/news/world-latin-america-38140981">killed 71 people</a> including <a href="http://www.telegraph.co.uk/news/2016/11/29/colombia-plane-carrying-brazil-football-team-crashes-latest/">most of one of Brazil’s top football teams</a>, leaving just six survivors. While the investigation may take some time to reveal the factors behind the accident, the distressingly high – but not total – number of fatalities raises the question of how some people are able to survive such a devastating disaster.</p>
<p>Aircraft accidents, especially those involving jet aircraft, are increasingly rare. According to the International Air Transport Association, 2015 saw one accident for <a href="http://www.iata.org/pressroom/pr/Pages/2016-02-15-01.aspx">every 3.1m flights</a>. That’s a spectacular achievement for an industry that is not much more than a century old and which involves transporting people at such high speeds in what can be challenging environments. But when an accident does occur, what is it that determines that some passengers survive when many others on the same flight do not?</p>
<p>The first factor is whether an accident is deemed “survivable” at all. While it may seem like a simple definition, there are actually “unsurvivable” accidents where people beat the odds. Unsurvivable accidents tend to be those where there is either a catastrophic loss of control or where the impact is at high velocity.</p>
<h2>Time to act</h2>
<p>The Air France aircraft that <a href="http://www.bbc.co.uk/news/world-europe-18720915">crashed into the Atlantic</a> in 2009 was a “<a href="https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100039467.pdf">loss of control in flight</a>” accident which no one could have survived because of the heavy impact with the sea. In contrast, while the loss of all hydraulic systems aboard a <a href="http://www.ntsb.gov/investigations/accidentreports/pages/AAR9006.aspx">United Airlines DC10 in 1989</a> should have resulted in the total loss of the aircraft, the heroic actions of the crew to steer the aircraft using only the thrust of the engines led to 185 survivors out of the 296 on board.</p>
<p>Accidents that happen in the cruise phase of flight, such as those involving a “controlled flight into terrain” tend to be less survivable. Such accidents happen without the crew being aware of a problem, so occur at high speed and without the cabin or its passengers being prepared for an accident. In these cases, survivors tend to be rare and the reasons behind their survival can be as random as whether they were thrown clear or were perhaps caught by a tree. </p>
<p>This was the case when there were only four survivors of a <a href="http://lessonslearned.faa.gov/ll_main.cfm?TabID=4&LLID=16&LLTypeID=2">1985 accident involving a JAL Boeing 747</a>, which killed 520 other people when the plane hit a mountainside following the separation of the aircraft’s tail.</p>
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<img alt="" src="https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147973/original/image-20161129-16998-1kpqozy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Work out where your nearest exit is.</span>
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</figure>
<p>The European Transport Safety Council estimates that <a href="http://etsc.eu/wp-content/uploads/1996_increasing_survival_rate_aircraft_accidents.pdf">90% of aircraft accidents are survivable</a> – something that does not necessarily match public expectation. Such a high rate of survival is due to improvements in crashworthiness (the science of making structures better able to cope with impact), the cabin environment, and crew training.</p>
<p>The materials we use now are less flammable. The seats better able to withstand impact forces. The exit routes are more clearly marked. The fire suppression systems are more effective and the space around exits is better designed to allow the fast flow of evacuating passengers. <a href="https://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=14837">Each of these developments</a> has been based on the investigation of previous accidents and the actions of safety regulators and manufacturers to improve standards.</p>
<h2>Seatbelts, brace, exits</h2>
<p>Yet the factors that affect survivability are many and varied. In accidents where a problem has been identified beforehand, the use of seatbelts, fastened tight and low, along with adopting a suitable brace position, is known to have a <a href="https://www.fire.tc.faa.gov/2010Conference/files/Cabin_Safety_I/SperberBracePosition/SperberBracePositionPres.pdf">tangible effect on whether you survive</a>. Those who listen to the safety announcement and who take notice of their nearest exit – for example, by counting the rows of seats in front or behind them – are more likely to get off an aircraft that is <a href="https://www.faa.gov/passengers/fly_safe/information">on fire or filled with smoke</a>. </p>
<p>Their <a href="https://www.atsb.gov.au/media/32733/grant_20040239.pdf">chances are also increased</a> by clear, assertive instructions by the cabin crew – safety is the main reason they are there after all. <a href="http://onlinelibrary.wiley.com/doi/10.1002/9780470686652.eae444/abstract">Sitting close to an exit</a> also helps, although those who do sit here need to be ready to act swiftly to avoid being crushed by fellow passengers trying to reach the exit.</p>
<p>External factors help, too. There are strict planning rules around airports to remove obstacles and to ensure that the airport fire service can reach any part of an aerodrome within three minutes of an accident. This has helped to <a href="http://www.icao.int/safety/Pages/Rescue-Fire-Fighting.aspx">greatly increase the number of survivors</a> who may once have survived the impact but not a subsequent fire because they could not evacuate from the aircraft.</p>
<p>Above all, passengers should remain vigilant. <a href="http://www.boeing.com/resources/boeingdotcom/company/about_bca/pdf/statsum.pdf">According to Boeing</a>, between 2006 and 2015, 66% of fatal aircraft accidents occurred as the aircraft was on the ground – during take-off or during final approach and landing. It is worth keeping your shoes on and wearing suitable clothing. Use the time to listen to the cabin crew’s briefing. The most likely result is that they will reward you with more attentive service, but if something does go wrong, it may well make all the difference – and even save your life.</p><img src="https://counter.theconversation.com/content/69595/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Graham Braithwaite does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>
The crash near Medellin killed 75 people, including many members of a top Brazilian football team, but amazingly left six survivors.
Graham Braithwaite, Director of Transport Systems, Professor of Safety & Accident Investigation, Cranfield University
Licensed as Creative Commons – attribution, no derivatives.