Summary The Reliability Trap: The crash of Emirates flight 521 | by Admiral Cloudberg | Medium admiralcloudberg.medium.com
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Two crash landings of Boeing 777s had no serious injuries, but Emirates Flight 521 had one fatality due to mistakes in the firefighting response and pilots' overreliance on automation.
Key Points
- Two Boeing 777 crash landings, Asiana Airlines Flight 214 and British Airways Flight 38, resulted in no serious injuries due to their sturdiness and the flight attendants' assertiveness.
- Emirates Flight 521 had a different outcome, with one fatality due to mistakes by the firefighting response.
- The cause of the crash was overreliance on automation, which led to pilots failing to monitor the plane's energy state.
- The GCAA issued 40 recommendations and Emirates took additional actions to prevent a similar accident from occurring again.
- The common factor between the two crashes was pilots not being aware of an edge case in the autothrottle.
Summaries
118 word summary
Two Boeing 777 crash landings, Asiana Airlines Flight 214 and British Airways Flight 38, resulted in no serious injuries due to their sturdiness and the flight attendants' assertiveness. Emirates Flight 521 had a different outcome, with 300 passengers and crew able to walk away from the crash unharmed, but with one fatality due to mistakes by the firefighting response. The cause of the crash was overreliance on automation, which led to pilots failing to monitor the plane's energy state. In addition, the GCAA issued 40 recommendations and Emirates took additional actions to prevent a similar accident from occurring again. The common factor between the two crashes was pilots not being aware of an edge case in the autothrottle.
1046 word summary
Crash landings of Boeing 777s, such as Asiana Airlines Flight 214 and British Airways Flight 38, have resulted in no serious injuries due to the plane's sturdiness and the flight attendants' assertiveness. This was exemplified on Emirates Flight 521 when all 300 passengers and crew were able to walk away from the crash unharmed. Emirates Flight 521 crashed due to a set of faulty assumptions not unique to the flight crew. The GCAA issued 40 recommendations to prevent a similar accident from occurring again, such as displaying the evacuation checklist in the cockpit and training controllers to pass on reports of wind shear. Emirates took additional actions, such as training pilots on go-arounds with inhibited TOGA switches and firefighting operations at UAE airports. Dubai International Airport also overhauled its firefighter training. The common factor between the two crashes of the Boeing 777 was overreliance on automation. Pilots often neglect to monitor automation due to its high reliability, but in the Emirates and Asiana crashes, it proved catastrophic. The only real solution is to instill pilots with an awareness of their aircraft's energy state, yet this is difficult to measure. The Asiana crash in 2013 was similar, with the pilots not being aware of an edge case in the autothrottle which led to the plane striking a seawall. The flight attendants on the Emirates crash handled the chaotic situation well, but the slides failed to meet design specifications. An investigation by the GCAA revealed numerous mistakes by the firefighting response which led to the sole fatality in the crash of Emirates Flight 521. The 2015 training exercise had already highlighted a lack of an on-scene chain of command, no coherent firefighting strategy, and no evacuation of passengers. The same failures occurred at the crash site and the lack of a firefighting strategy allowed the landing gear fire to spread to the fuel tanks. Furthermore, no dynamic risk analysis was undertaken and the firefighting team was working close to the wing when it blew up. The pilots were also found to have failed to notice that engine thrust had not increased due to a lack of observation and communication. The crash could have been avoided when the captain retracted the landing gear, four seconds into the go-around. Unusual wind conditions combined with pilots’ lack of knowledge of the TOGA switch inhibition feature upon touchdown, a Boeing 777 training program lacking information about the feature, and a flight operations manual that did not specify that thrust should be added manually in a go-around led to the crash of Flight 521. The wind shear detection system was not installed and the air was too dry for it to be effective. Pilot interviews and flight data analysis revealed that the combination of an early flare, thermals rising from the runway, and a tailwind-to-headwind wind shear prevented the crew from landing inside the prescribed touchdown zone, forcing a go-around. When the captain pressed the TOGA switches, they were inhibited and nobody noticed that thrust was not increasing until it was too late. Emirates Flight 521 crash landed in Dubai, prompting an investigation by the UAE's GCAA. Miraculously, all 300 passengers and crew escaped, although 4 flight attendants and 21 passengers were injured. The lead flight attendant and pilots stayed on board trying to find a 7-year-old girl who had been separated from her family. Unfortunately, a firefighter was killed in the explosion, and 8 first responders were seriously injured. The little girl ultimately escaped via a different exit and was reunited with her parents on the runway. Firefighters rushed to stabilize the escape slides after they were rendered unusable by the wind, allowing some passengers to evacuate. Inside the cabin, chaos reigned with panicking passengers and 67 young children on board. As firefighters fought visible flames, no one noticed the growing blaze in the landing gear bay. Flight attendants struggled to find the evacuation checklist and hesitated to order an evacuation, resulting in passengers attempting to retrieve luggage. Eventually, only three exits were usable for 282 passengers to escape before fire consumed the plane. The Captain declared a Mayday and the airport's fire station scrambled to respond. Flight 521, a Boeing 777 carrying 300 passengers and crew, slammed back down onto the runway and slid 800 meters, shearing off its right engine. The captain called out “Wind shear, TOGA!” as he manually applied max power, but the autothrottle failed to increase engine power. The TOGA switches are inhibited on landing after touchdown, so pressing them wouldn't do anything. The captain performed a go-around sequence and the computerized voice called out “LONG LANDING” as the main landing gear bogies made contact with the runway. Emirates Flight 521 experienced a rapid sequence of events that caused it to veer off course during descent. The pilots raised the nose too soon due to the 68˚C (154˚F) heat of the runway, which caused thermals to reduce the plane's descent rate. The wind shear then caused the airspeed to increase by 12 knots (22km/h), further extending the glide. The captain mistakenly attributed the plane's increased performance to hot air rising off the runway. Weather conditions in Dubai at the time were unusual, with a high pressure system bringing high temperatures and two low pressure systems off the coast, generating a hot wind towards the sea. This caused wind shear to form on runway 12 Left, which the pilots weren't expecting based on available weather reports. Two other flights had to abort their landings due to the wind shear but this wasn't communicated to Emirates Flight 521. Emirates Flight 521 was a regularly-scheduled flight from Thiruvananthapuram, India to Dubai in the United Arab Emirates. On board were 282 passengers, two pilots and 16 flight attendants. The captain was from the UAE and the first officer from Australia. Emirates had not suffered an aircraft loss or fatal accident since 1985, and the 2020 UAE report outlined a complex sequence of events that led to the near disaster. On Aug. 3, 2016, the Boeing 777 touched down too far along the runway and activated go-around mode, but crashed back onto the runway. All 300 passengers and crew managed to escape, but a firefighter was killed in an explosion minutes later. The crash highlighted the danger of overreliance on sophisticated automation.