Ethiopia plane crash: Faulty sensor data led to crash that killed 157 people, report finds
Ethiopia's transport minister says the flight's crew performed correct procedures repeatedly but were unable to control the jet.
Friday 5 April 2019 11:20, UK
Pilots on the doomed Ethiopian Airlines jet wrestled with controls as it plunged to the ground after faulty sensor data led to the plane nose-diving, a preliminary report has found.
Ethiopia's transport minister said the flight's crew performed correct procedures repeatedly but were unable to control the jet before it crashed last month, killing all 157 people on board.
The findings have drawn the strongest link yet between the Ethiopia disaster and a crash five months earlier off the coast of Indonesia, which both involved Boeing 737 MAX 8 jets.
Both planes had an automated system that pushed the aircraft's nose down when sensor readings detected the danger of an aerodynamic stall.
The Ethiopian government has now urged Boeing to review its flight control technology.
Ethiopian investigators did not blame anyone for the crash, stressing the importance of international rules requiring civil probes to focus on recommendations for safer flight.
But in a clear indication of where Ethiopian investigators are directing the attention of regulators, they cleared the pilots of using incorrect procedures and issued two safety recommendations focused on the aircraft.
"The crew performed all the procedures repeatedly provided by the manufacturer but was not able to control the aircraft," transport minister Dagmawit Moges told a news conference.
"Since repetitive uncommanded aircraft nose down conditions are noticed... it is recommended that the aircraft control system shall be reviewed by the manufacturer."
The Boeing jet crashed six minutes after take-off and most of the wreckage was found buried in the ground, according to the report by Ethiopia's aircraft accident investigation bureau.
The Boeing 737 MAX 8 was grounded globally following the crash, which was the second deadly accident in six months involving the new model.
A Lion Air 737 MAX 8 crashed in Indonesia in October, killing all 189 passengers and crew.
A more in-depth final report into the Ethiopia crash is expected to take several months and is due within a year.
Investigators for the crashes have been focusing on a 737 MAX system known as Manoeuvring Characteristics Augmentation System (MCAS).
If MCAS believes the plane is climbing too steeply, indicating a likely stall, it moves stabilisers at the rear of the plane to automatically adjust the angle of flight.
The preliminary reports on both planes suggest MCAS was being fed faulty data, leading it to repeatedly and automatically push the nose of the plane down, when it shouldn't have been.
Now a debate is raging within the aviation community over what the Ethiopian report means.
Captain Jason Goldberg, spokesman for the American Airlines pilots' union, told Sky News: "If the preliminary report is correct, it appears that the pilots accomplished the manufacturer's recommended procedures and it did not allow them to gain control of the aircraft."
When questioned about the preliminary report revealing that the pilots seemed to turn MCAS back on, just 20 second before the crash, Mr Goldberg said: "It appears that the pilots restored the electric pitch trim as a last ditch effort to regain control."
But other pilots for major US airlines, who wish to remain anonymous because they were not authorised to discuss the issue publicly, view the Ethiopian report very differently.
They point to the aircraft's high airspeed, questioning why that was, and said re-engaging MCAS is not part of Boeing's recommended procedure.
Others familiar with the aircraft have said that although the Ethiopian transport ministry have suggested there was no sign of any structural damage to the plane, the massive discrepancy between the two sensors feeding MCAs suggests that one of them could have been damaged by a glancing bird strike.
Ethiopian Airlines said the preliminary report clearly showed the crew followed correct procedures "to handle the most difficult emergency situation created" on the plane.
"Despite their hard work and full compliance with the emergency procedures it was very unfortunate that they could not recover the plane from the persistence of nosediving," the airline said.
"As the investigation continues with more detailed analysis as usual we will continue with our full co-operation with the investigation team."
The airline's group chief executive Tewolde GebreMariam said everyone at Ethiopian Airlines "are still going through deep mourning" and expressed "deep sympathy and condolences for the families' relatives and friends of the victims".