Ethiopian investigators are mostly blaming Boeing for last year’s crash of a Ethiopian Airlines jet shortly after take-off, saying in an interim report that there were design failures in the jet and inadequate training for pilots.
The update from Ethiopian investigators — timed to beat the anniversary of the crash on March 10 — pointed to the role played by a new flight-control system that Boeing installed on the 737 Max which repeatedly pushed the nose of the plane down.
The system, called MCAS, overwhelmed the pilots’ attempts to control the plane. When it triggered for the fourth and final time, the pilots fought back by pulling on their control columns with up to 180lb of force, but the nose of the plane sank even more and the jet flew even faster.
Shortly before impact, the plane was streaking downward at 575mph with its nose tilted down at a 40-degree angle, according to the interim report from Ethiopia’s Aircraft Accident Investigation Bureau.
All 157 people on board were killed when flight 302 crashed into a field six minutes after take-off from Addis Ababa. Every Max jet worldwide was grounded within days of the crash — the second involving a Boeing Max in less than five months.
The investigators issued several recommendations to Boeing and placed little blame on the airline or its pilots. In that regard, the Ethiopian update differed from a final report Indonesian investigators issued after a 737 Max operated by Lion Air crashed in October 2018 and killed all 189 people on board.
Data in the Ethiopian update could renew questions about the pilots’ actions – in particular, their decision to turn MCAS back on after first disabling it when the plane’s nose pitched down. One aeronautics expert said restoring power to MCAS doomed the flight.
Monday’s interim report was not remarkably different from a preliminary report the government issued last April. Boeing and the US Federal Aviation Administration said they were reviewing the update, but both already seemed to be looking ahead to a final report the Ethiopians are expected to issue later this year.
It came as a report said the Max could be grounded longer than Boeing expected while the company fixes a wiring problem with the planes. Wiring bundles are too close together, raising the risk of short-circuiting and fire in extreme situations. Boeing has been analysing the issue for several weeks.
The Wall Street Journal reported that FAA managers and engineers have recommended requiring Boeing to move the wiring on nearly 800 Max jets, which could further delay the schedule for returning the planes to flight later this year.
The FAA said on Monday it was continuing to discuss the matter with Boeing, and that the plane will only be cleared to fly when the agency is satisfied all safety-related issues have been fixed.
The interim report came three days after a congressional report said Boeing’s development of the Max was marred by design failures and a “culture of concealment” to hide information from regulators and airlines.
The Ethiopian board made six recommendations, all aimed at Boeing or the FAA, which certified the plane in 2017.
Boeing is addressing some of the recommendations by changing MCAS to make it less powerful. Boeing is also endorsing the use of flight simulators to train pilots on how MCAS makes flying the Max different from previous models of the 737.
There were no recommendations for Ethiopian Airlines, which has defended the actions of its pilots.