Pilots on the Asiana Airlines flight that crashed in San Francisco last year get most of the blame in a report today by U.S. safety officials. The investigation faults the pilots for mismanaging their approach to the airport, relying on automatic flight controls they didn’t fully understand, and failing to notice their speed was too slow.
The crew of Asiana Flight 214 also decided to abort their landing far too late, according to the report, and the Boeing 777 ended up striking a sea wall before breaking apart, spinning nearly 360 degrees and catching fire near the runway. The report cites pilot fatigue as a factor in the July 6, 2013, accident. The crew was landing the flight from Seoul just before noon local time—or 3:30 a.m. Korea time.
The National Transportation Safety Board convened its final hearing on the crash, which killed three people and seriously injured 49 others. One of the fatalities, a 16-year-old girl from China, was ejected from the plane and killed by an emergency vehicle responding to the scene. “The flight crew over-relied on automated systems that they did not fully understand and flew the aircraft too low and too slow,” said Christopher Hart, the NTSB’s acting chairman.
Asiana has already revised its pilot training procedures, acknowledging that its pilots needed more hand flying experience to avoid dependency on flight-control computers that have heavily automated much of commercial flying. Such systems have dramatically increased flight safety but also threaten to become so complex that many pilots do not fully comprehend how they work.
That was the case on the Asiana flight. Five miles from the airport, the plane was 450 feet too high. Investigators found that much of the crew’s workload and confusion stemmed from their efforts to remedy their approach.
The pilot flying the approach, Captain Lee Kang Kuk, was being trained on the 777 and did not realize that he had put the flight-control system into a mode that disabled the jet’s speed protection system. The Boeing’s automated throttle system provides thrust as needed to maintain airspeed but was shut off as the captain took manual control to lower the plane’s pitch—and none of the three pilots noticed.
“This is another in a long line of accidents involving problems with interactions between pilots and automated systems,” William Bramble, an NTSB human-performance investigator, testified during the final hearing.
What role, if any, Boeing’s flight controls played in the mishap was one of the board’s major considerations in the crash. Board member Robert Sumwalt, a former commercial pilot, said that many pilots and even some instructors do not fully understand all of the auto-throttle’s various settings.
Boeing noted in its comments to the investigative team that the airplane functioned as designed. “Boeing respectfully disagrees with the NTSB’s statement that the 777′s auto-flight system contributed to this accident, a finding that we do not believe is supported by the evidence,” spokesman Doug Alder Jr. said in an e-mail today.
The NTSB also recommended further study of the forces in the crash, which led to a high number of upper spinal injuries. The agency concluded that the factors contributing to these types of injuries are poorly understood.