PARIS -- The co-pilot of the doomed Germanwings flight repeatedly sped up the plane as he used the automatic pilot to descend the A320 into the Alps, the French air accident investigation agency said Friday.
The chilling new detail from the BEA agency is based on an initial reading of the plane's "black box" data recorder, found blackened and buried at the crash site Thursday.
It strengthens investigators' initial suspicions that co-pilot Andreas Lubitz intentionally destroyed the plane -- though prosecutors are still trying to figure out why. All 150 people aboard Flight 9525 from Barcelona to Duesseldorf were killed in the March 24 crash.
The BEA said the preliminary reading of the data recorder shows that the pilot used the automatic pilot to put the plane into a descent and then repeatedly during the descent adjusted the automatic pilot to speed up the plane. The agency says it will continue studying the black box for more complete details of what happened.
Based on recordings from the plane's other black box, the cockpit voice recorder, investigators say Lubitz locked the pilot out of the cockpit and deliberately crashed.
Lubitz spent time online researching suicide methods and cockpit door security in the week before crashing Flight 9525, prosecutors said Thursday -- the first evidence that the fatal descent may have been a premeditated act.
German prosecutors have said Lubitz's medical records from before he received his pilot's license referred to "suicidal tendencies," and Lufthansa, Germanwings' parent company, said it knew six years ago that Lubitz had had an episode of "severe depression" before he finished his flight training.
CBS News correspondent Allen Pizzey reported that Lufthansa now faces an enormous bill for the recovery operation in the Alps -- and a the possibility of even more enormous law suits. The airline has already asked its insurers to set aside $300 million to cover the costs associated with the incident.
In Marseille, prosecutor Brice Robin underlined French investigators' conviction that he was conscious until the moment of impact, and appears to have acted repeatedly to stop an excessive speed alarm from sounding.