AP Photo/Mulugeta Ayene
- Pilots on the Ethiopian Airlines 737 Max plane which crashed in March followed Boeing’s emergency procedures, but still couldn’t control the plane and prevent the disaster, preliminary findings from an investigation have reportedly found.
- Sources familiar with the investigation told the Wall Street Journal that the pilots followed Boeing’s procedures and turned off the MCAS software system, but then turned it back on again and tried other steps to control the plane.
- The MCAS system automatically points the nose of the plane downward in some circumstances to prevent stalls, and is the subject of the most widely discussed theory for what was behind the fatal Ethiopian Airlines and Lion Air 737 Max crashes, which killed almost 350 people.
- How the 737 Max was approved for flying has come under increased scrutiny from lawmakers since the crashes. Boeing is working on a fix that the FAA said it will not implement until it was satisfied.
The pilots on the doomed Ethiopian Airlines 737 Max plane which crashed shortly after takeoff in March followed Boeing’s emergency procedures but still couldn’t stop the disaster, according to a report into the preliminary findings of an investigation into the crash.
Unnamed sources familiar with the investigation told The Wall Street Journal that the pilots on the doomed flight initially responded to the plane pushing its nose down by turning off the automated anti-stall system that is widely thought to have been behind the crash. When that didn’t work, the Journal reports, the pilots turned the system back on and tried other steps to control the plane.
All 157 people on board were killed when the plane crashed soon after taking off from Addis Ababa’s Bole International Airport on March 10.
A potential failure of the automated system, called the Maneuvering Characteristics Augmentation System (MCAS), has been the most widely discussed theory for the Ethiopian Airlines crash, and also the Lion Air Boeing 737 Max 8 crash that killed 189 people in October.
The system is designed to prevent stalls by automatically pointing the nose of the plane downward if it senses the aircraft climbing too sharply.
REUTERS/Tiksa Negeri/File Photo
Boeing and the FAA sent bulletins to 737 MAX operators after the Lion Air crash, reminding them of procedures to follow in case the plane’s system pushed the nose down. They told pilots to disable MCAS by cutting its power.
Government and industry officials said the pilots likely turned the MCAS system back on because using manual controls to raise the nose didn’t work as needed, the WSJ reported.
Pilots turned a manual wheel that controls the parts of the plane’s tail that the MCAS system controls, sources told the WSJ, but they then turned electronic power back on. They then used electric switches to try and raise the plane’s nose, but that also reactivated MCAS, continuing to push the plane’s nose downwards.
These details are based on the black box flight recorders from the flight, the sources said.
The Wall Street Journal also reported last week that the preliminary conclusion into the Ethiopian Airlines crash was that the MCAS system mistakenly activated during the fatal flight. This conclusion is subject to change.
Investigations into both crashes are ongoing.
Boeing is introducing new software for the planes, which have been grounded around the world and will not be allowed to fly until regulators approve the fixes, most of which are to the MCAS system.
The FAA announced on Monday that it expects Boeing to submit the final software fixes for the 737 Max "over the comings weeks" and that it would not approve the software until it was satisfied — a delay that means airlines could keep the planes grounded for weeks longer than expected.
Lawmakers are looking at the plane’s approval to fly with increased scrutiny, with particular focus being put on the policy that allows Boeing to partially certify its own aircraft on behalf of the FAA. Acting FAA head Dan Elwell told a Senate committee that Boeing partly certified the MCAS software system itself.
Whistleblowers also warned of possible serious safety issues in the inspection program for new aircraft, including the 737 Max. They alleged that "numerous FAA employees, including those involved in the Aircraft Evaluation Group (ARG) for the Boeing 737 MAX, had not received proper training and valid certifications," senators said on Monday.
- Senate investigating whistleblowers’ claims that government safety inspectors who approved Boeing’s 737 Max plane lacked sufficient training
- FAA expects Boeing to come up with new software to fix the grounded 737 Max in a matter of weeks
- Investigators are close to confirming the lead theory about why the Ethiopian Airlines 737 Max crashed, report says