A screw-like device found in the wreckage of the Boeing 737 Max 8 that crashed Sunday in Ethiopia has provided investigators with an early clue into what happened, as work begins in France to decode the black boxes recovered from the scene.
The so-called jackscrew, used to set the trim that raises and lowers the plane's nose, indicates the jet was configured to dive, based on a preliminary review, according to a person familiar with the investigation. The evidence helped persuade U.S. regulators to ground the model, said the person, who requested anonymity to discuss the inquiry.
France's aviation safety agency BEA received the cockpit voice and data recorders on Thursday for decoding, while investigators on the scene near Addis Ababa continue to sift through the plane's wreckage. The second crash in five months has thrown Boeing into a crisis, sending shares plunging and raising questions about the future of its bestselling jet.
Separately, the New York Times reported that doomed Ethiopian Airlines Flight 302 to Nairobi was in trouble almost immediately after takeoff as it lurched up and down by hundreds of feet at a time. The captain asked in a panicky voice to turn back only three minutes into the flight as the plane accelerated to abnormal speeds, the newspaper reported, citing a person who reviewed the jet's air traffic communications.
"Break break, request back to home," he told air traffic controllers as they scrambled to divert two other flights approaching the airport. The aircraft had accelerated far beyond what is considered standard practice. All contact between air controllers and the aircraft was lost five minutes after it took off, the report said.
Federal Aviation Administration chief Daniel Elwell on Wednesday cited unspecified evidence found at the crash scene as part of the justification for the agency to reverse course and temporarily halt flights of Boeing's largest selling aircraft. Up until then, American regulators had held off even as nation after nation had grounded the model.
The jackscrew, combined with a newly obtained satellite flight track of the plane, convinced the FAA that there were similarities to the Oct. 29 crash of the same Max model off the coast of Indonesia. In the earlier accident, a safety feature on the Boeing aircraft was repeatedly trying to put the plane into a dive as a result of a malfunction.
All 157 people aboard the Ethiopia flight died when the plane crashed. The jet's flight recorders are in France, where they are being analyzed at the BEA's laboratories. "The investigation process has started in Paris," Ethiopian Airlines said in a Twitter post on Friday.