U.S. aviation officials believe a bird strike may have led to the deadly crash of an Ethiopian Airlines Boeing 737 Max in March, according to a person familiar with the matter.
Boeing shares were up 1.7% in premarket trading.
The fast-selling Boeing 737 Max airplanes have been grounded since shortly after that accident, which came less than five months after a similar crash in Indonesia. Together, the two crashes killed 346 people.
Crash investigators have indicated that bad sensor data triggered an anti-stall system aboard the Ethiopian Airlines Boeing 737 Max that went down shortly after takeoff in March, a similar scenario to a crash of the same type of plane in Indonesia in October. The system automatically pushes the nose of the plane down if it perceives the aircraft is in a stall, the normal way to recover from such a position. That can be catastrophic if the plane is not in a stall, however, and the two planes were sent into fatal dives.
U.S. aviation officials think a bird strike is the likely culprit in erroneous sensor data that fed the anti-stall system in the Ethiopian Airlines crash. Ethiopian Airlines officials have said that a preliminary crash investigation report showed "no evidence of any foreign object damage" such as a a bird strike, on the sensor.
While the investigation is ongoing and a final cause of the Ethiopian Airlines crash has not yet been determined, Boeing's anti-stall system is under fire.
Pilots have complained that the manufacturer did not inform them the system was on the plane until after the crash in Indonesia in October. Boeing last Thursday said it has completed a software fix for system, known as MCAS, to be less powerful and give pilots greater control. It has also developed new training material for pilots and the changes are under review by the FAA.
The Wall Street Journal reported the news earlier.