In response to a public records request, the National Transportation Safety Board released a report recently on what the Boeing 737-800’s flight data recorder revealed. The NTSB became involved in the Chinese investigation because the plane and engines were made by American companies and the U.S. investigators are regarded as the world’s leading experts on analyzing black boxes after a crash.
The report offers the best explanation yet about what caused the crash and confirms news stories at the time suggesting the crew may have played a role after Chinese investigators said they did not immediately find a problem with the plane.
Aviation safety experts agree that the data shows the fuel to both engines was cut off and someone sent the plane into a nosedive and a 360-degree roll, but it does not conclusively show exactly what happened because the Civil Aviation Administration of China has yet to release its final report than four years later. International standards call for investigators to strive to release their report by roughly a year after a crash.
The NTSB report was released May 1.
Likely intentional fuel cut
By design the fuel levers in a 737 cannot be easily bumped or shut off inadvertently — someone has to pull them out to release them before they will move. John Cox, CEO of Safety Operating Systems, said the levers lock into place, so it’s likely that someone deliberately moved them both to the cutoff position.
The data ended while the plane was still at 26,000 feet (7,900 meters) of altitude after the flight recorder and all the plane’s hydraulic systems lost power, but the report of the 12 minutes before that suggests what happened.
The cockpit voice recorder, which continued working because it had a battery backup, could also help shed light, but the NTSB did not release a transcript of what it found on those recordings. It is up to Chinese authorities to release those details.
Jeff Guzzetti, who formerly investigated crashes for the NTSB and the Federal Aviation Administration, said the flight data suggests a struggle and the crash could have been a pilot suicide. There have been a number of previous instances of that, including a Germanwings flight that crashed into the French alps in 2015, killing everyone aboard.
“Typically when you want to roll an airplane, it’s a smooth movement of the control wheel in one direction. But here you have it moving back and forth, back and forth, as if someone is trying to counter the initial movement of the roll,” Guzzetti said. “So it’s not conclusive, but it sure has the earmarks of a struggle in the cockpit.”
Pilots’ mental health
The details about this crash will renew longstanding industry concerns about how to ensure pilots’ mental health.
Many are reluctant to come forward and seek help for fear they could lose their medical certification and be grounded. Getting recertified can take months or longer during which a grounded pilot is not getting paid. Meanwhile some countries prohibit pilots from taking common psychiatric medicines such as antidepressants.
“Clearly pilots — and very understandably so — are oftentimes reluctant to come forward, knowing that to get recertified after having gone through a mental health evaluation, it can be very arduous and very lengthy,” Cox said.
Guzzetti said the co-pilot of an Egypt Air plane that crashed in 1999 is believed to have deliberately sent it into the ocean off New York. In 2023, in an incident that did not end in a crash, an off-duty pilot who took psychedelic mushrooms days beforehand tried to cut the engines of a Horizon Air flight while riding off-duty in the cockpit.
Plane plowed into a mountainside
The jet was flying from Kunming in the southwest to Guangzhou, near Hong Kong, when it went into a nosedive at about 8,800 meters (29,000 feet), appeared to recover but then slammed into the mountain. The crash left a 65-foot (20-meter) crater and set the forest on fire.
The crew reported no problems before losing contact with air traffic control. Chinese investigators said no abnormalities were found among the plane or crew or with outside elements such as bad weather.
Cox also said the new report from the NTSB does not indicate any problem with the plane.
The March 21, 2022, crash was a rare failure for the Chinese airline industry, which dramatically improved safety following deadly crashes in the 1990s. China Eastern is one of four major state-owned airlines in the country.
