Six minutes of chaos in cockpit of doomed Ethiopian 737 revealed: Pilots fought to regain control from computers as systems put the Boeing in a dive while simultaneously shrieking ‘don’t sink’ warnings
Chilling black-box tapes illustrate a scene of confusion and chaos in the cockpit
Almost from the moment they took off the pilots were bombarded by alarms
At one point they were both hauling on their controls in unison as it nose dived
A 33-page preliminary report was released by Ethiopian authorities on Thursday
Chilling black-box recordings from inside the doomed Ethiopian Airlines Boeing 737 Max cockpit paint a chilling picture of chaos as the pilots were bombarded by alarms and failure warnings for six minutes.
Almost immediately after roaring down the runway in Addis Ababa, a device called a stick shaker began vibrating the captain’s control column, warning him that the plane might be about to stall and fall from the sky.
Just one minute into Flight 302 to Nairobi in neighbouring Kenya, Captain Yared Mulugeta Gatechew, 29, reported that they were having flight-control problems.
Then the anti-stall system kicked in and pushed the nose of the plane down for nine seconds.
At times the captain and his co-pilot Ahmednur Mohammed, 25, were desperately heaving back in unison on their controls as they tried to keep the colossal jet from plummeting down.
Ethiopian authorities issued a preliminary report on Thursday following the March 10 crash that killed all 157 people on board which includes a minute-by-minute narrative of a black-box recording.
Instead of climbing, the plane descended slightly. Audible warnings – ‘Don’t Sink’ – sounded in the cockpit.
The pilots fought to turn the nose of the plane up, and briefly they were able to resume climbing.
But the automatic anti-stall system pushed the nose down again, triggering more squawks of ‘Don’t Sink’ from the plane’s ground-proximity warning system.
Following a procedure that Boeing reiterated after the Lion Air crash, the Ethiopian pilots flipped two switches and disconnected the anti-stall system, then tried to regain control.
They asked to return to the Addis Ababa airport, but were continuing to struggle getting the plane to gain altitude.
Then they broke with Boeing procedure and returned power to controls including the anti-stall system, perhaps hoping to use power to adjust a tail surface that controls the pitch up or down of a plane, or maybe out of sheer desperation.
One final time, the automated system kicked in, pushing the plane into a nose dive, according to the report.
A half-minute later, the cockpit voice recording ended, the plane crashed, and all 157 people on board were killed. The plane’s impact left a crater ten meters deep.
The preliminary report found that a malfunctioning sensor sent faulty data to the Boeing 737 Max 8’s anti-stall system and triggered a chain of events that ended in a crash so violent it reduced the plane to shards and pieces.
The pilots’ struggle, and the tragic ending, mirrored an October 29 crash of a Lion Air Max 8 off the coast of Indonesia, which killed 189 people.
The anti-stall system, called MCAS, automatically lowers the plane’s nose under some circumstances to prevent an aerodynamic stall.
Boeing acknowledged that a sensor in the Ethiopian Airlines jet malfunctioned, triggering MCAS when it was not needed. The company repeated that it is working on a software upgrade to fix the problem in its best-selling plane.
‘It’s our responsibility to eliminate this risk,’ CEO Dennis Muilenburg said in a video. ‘We own it, and we know how to do it.’
Jim Hall, a former chairman of the National Transportation Safety Board, said the preliminary findings add urgency to re-examine the way that the Federal Aviation Administration uses employees of aircraft manufacturers to conduct safety-related tasks, including tests and inspections – a decades-old policy that raises questions about the agency’s independence.
It is now under review by the U.S. Justice Department, the Transportation Department’s inspector general and congressional committees.
‘It is clear now that the process itself failed to produce a safe aircraft,’ Hall said. ‘The focus now is to see if there were steps that were skipped or tests that were not properly done.’
The 33-page preliminary report, which is subject to change in the coming months, is based on information from the plane’s flight data and cockpit voice recorders, the so-called black boxes.
The Max is Boeing’s newest version of its workhorse single-aisle jetliner, the 737, which dates to the 1960s. Fewer than 400 Max jets have been sent to airlines around the world, but Boeing has taken orders for 4,600 more.
Boeing delivered this particular plane, tail number ET-AVJ, to Ethiopian Airlines in November. By the day of Flight 302, it had made nearly 400 flights and been in the air for 1,330 hours – still very new by airline standards.
The pilots had a scant 159 hours of flying time on the Max.
The captain, Getachew, had accumulated more than 8,000 hours of flying since completing work at the airline’s training academy in 2010.
He had flown more than 1,400 hours on Boeing 737s but just 103 hours on the Max.
That may not be surprising, given that Ethiopian Airlines had just five of the planes, including ET-AVJ.
The co-pilot, Mohammed, was only 25 and was granted a license to fly the 737 and the Max on December 12 of last year.
He had logged just 361 flight hours – not enough to be hired as a pilot at a U.S. airline. Of those hours, 207 were on 737s, including 56 hours on Max jets.
Pilots “repeatedly” followed procedures recommended by Boeing before the crash of an Ethiopian plane on March 10, according to the first official report into the disaster.
Boeing’s boss has admitted for the first time a failure in the jet’s anti-stall system was a factor in the crash.
Flight ET302 crashed after take-off from Addis Ababa, killing 157 people.
Despite their efforts, pilots “were not able to control the aircraft”, Transport Minister Dagmawit Moges said.
It was the second crash of a Boeing 737 Max aircraft in five months.
Last October, Lion Air flight JT 610 crashed into the sea near Indonesia killing all 189 people on board.
In a news conference in Addis Ababa, Ms Dagmawit said: “The crew performed all the procedures repeatedly [that were] provided by the manufacturer but were not able to control the aircraft.”
The 737 Max family of aircraft was grounded following the Ethiopian Airlines crash, a move affecting more than 300 planes.
What did the report say about the cause of the crash?
The preliminary report did not attribute blame for the crash. But it says the crew were fully qualified to conduct the flight, and that they performed all the expected procedures correctly.
The report goes on to recommend that Boeing review the 737 Max’s “flight control system related to flight controllability” and that aviation regulators ensure this is done before the aircraft goes back into the air.
Crash investigators have focused their attention on the Manoeuvring Characteristics Augmentation System (MCAS) – software designed to help prevent the 737 Max from stalling.
The software reacts when sensors in the nose of the aircraft show the jet is climbing at too steep an angle, which can cause a plane to stall.
The report does not mention the MCAS by name, but it does detail during the minutes after take off the problems the pilots were having in trying to control the aircraft’s angle of flight.
At one point the captain called out three times “pull up”, and seconds after instructed the first officer to tell Air Traffic Control that they had a flight control problem.
In a statement on Thursday, the chief executive of Ethiopian Airlines, Tewolde GebreMariam, said he was “very proud” of the pilots’ “high level of professional performance”.
“It was very unfortunate they could not recover the airplane from the persistence of nosediving,” the airline said in a statement.
Mr Dennis Muilenburg, Chairman, President and Chief Executive Officer, Boeing Company, has said the company will complete the software update of the Maneuvering Characteristics Augmentation System (MCAS) in 737 Max aircraft.
Muilenburg disclosed this in a statement on Friday in response to the preliminary report on its crashed flight 302, released by the Ethiopian Accident Investigation Bureau on Thursday.
He said that the full details of what happened in both Lion Air and Ethiopian accidents would be issued by the government authorities in the final reports.
Boeing president added with the release of the preliminary report of the Ethiopian Airlines Flight 302 accident investigation, it was apparent that in both flights, the MCAS was activated in response to erroneous angle of attack information.
According to him, the history of our industry shows most accidents are caused by a chain of events.
He said that it was the similar case in the recent two accidents, adding that pilots had stated that erroneous activation of the MCAS function could add to what was already a high workload environment.
According to Muilenburg, it is our responsibility to eliminate this risk; we own it and we know how to do it.
“From the days immediately following the Lion Air accident, we have had teams of our top engineers and technical experts working tirelessly in collaboration with the Federal Aviation Administration and our customers to finalize and implement a software update that will ensure accidents like that of Lion Air Flight 610 and Ethiopian Airlines Flight 302 never happen again.
“We are taking a comprehensive, disciplined approach, and taking the time, to get the software update right.
“We’re nearing completion and anticipate its certification and implementation on the 737 MAX fleet worldwide in the weeks ahead.
“We regret the impact the grounding has had on our airline customers and their passengers.
“This update, along with the associated training and additional educational materials that pilots want in the wake of these accidents, will eliminate the possibility of unintended MCAS activation and prevent an MCAS-related accident from ever happening again.
“We at Boeing take the responsibility to build and deliver airplanes to our airline customers and to the flying public that are safe to fly, and can be safely flown by every single one of the professional and dedicated pilots all around the world. This is what we do at Boeing,” he said.
The CEO expressed confidence in the fundamental safety of the 737 MAX, assuring that all who fly on it—the passengers, flight attendants and pilots, including families and friends deserved the best from Boeing.
He also assured that when the MAX returns to the skies with the software changes to the MCAS function, it would be among the safest airplanes ever to fly.
“We’ve always been relentlessly focused on safety and always will be; it is at the very core of who we are at Boeing and we know we can always be better.
“Our team is determined to keep improving on safety in partnership with the global aerospace industry and broader community because it is this shared sense of responsibility for the safety of flight that spans and binds us all together.
“We know lives depend on the work we do and that demands the utmost integrity and excellence in how we do it.
“With a deep sense of duty, we embrace the responsibility of designing, building and supporting the safest airplanes in the skies. We know every person who steps aboard one of our airplanes places their trust in us.
“Together, we’ll do everything possible to earn and re-earn that trust and confidence from our customers and the flying public in the weeks and months ahead.
“Again, we’re deeply saddened by and are sorry for the pain these accidents have caused worldwide. Everyone affected has our deepest sympathies,” he said.