- Pilots on the Ethiopian Airlines 737 Max plane that crashed in March followed Boeing’s emergency procedures before apparently seeking alternative methods to save the plane, 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 in turning off the MCAS anti-stall software but then turned it back on.
- The MCAS software, designed to point the plane’s nose down if the plane anticipates a stall, is behind the most widely posited theory for what was behind the fatal Ethiopian Airlines and Lion Air 737 Max crashes, which together killed almost 350 people.
- The 737 Max’s approval process has come under increased scrutiny from lawmakers since the crashes. Boeing is working on a software update.
The pilots on the doomed Ethiopian Airlines 737 Max plane that crashed shortly after takeoff in March followed Boeing’s emergency procedures before apparently seeking alternative methods to save the plane, The Wall Street Journal reported Tuesday, citing people familiar with the preliminary findings of an investigation into the crash.
Unnamed sources familiar with the investigation told The Journal that the pilots initially responded to the plane pushing its nose down by cutting power to the automated anti-stall system that is widely thought to have been behind the crash. That apparently didn’t work, The Journal reported, with the pilots later turning the system back on as they seemed to try other steps to control the plane.
All 157 people on board were killed when the plane crashed in Ethiopia soon after taking off from Addis Ababa’s Bole International Airport on March 10.
A failure of software known as the Manoeuvring Characteristics Augmentation System has been the most widely discussed theory for both the Ethiopian Airlines crash and 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 the plane senses the aircraft climbing too sharply. Because the system relied on readings from only a single sensor, observers have suggested a faulty sensor reading could incorrectly activate the system.
After the Lion Air crash, Boeing and the US Federal Aviation Administration sought to highlight procedures meant to solve any problems with the MCAS software. Those procedures involved disabling MCAS by cutting its power.
The Journal said that flight data from the so-called black box, however, indicated that the Ethiopian Airlines pilots did indeed cut power to the anti-stall system. That apparently didn’t work, The Journal said, because they then turned electronic power back on – which reactivated MCAS – while trying alternative methods to raise the plane’s nose.
The 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, as investigations into both crashes are ongoing.
Boeing is designing new software for the planes, which have been grounded around the world in the meantime.
The FAA on Monday announced that it expected 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. The 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.
Business Insider Emails & Alerts
Site highlights each day to your inbox.