PARIS -- Information retrieved from the "black box" data recorder of a doomed German jet shows its co-pilot repeatedly accelerated the plane before it slammed into the French Alps, investigators said Friday.
France's air accident investigation agency, BEA, provided the disturbing new details a day after a gendarme found the blackened data recorder buried in debris scattered along a mountainside ravine.
Based on an initial reading of the recorder, the revelation strengthened investigators' early suspicions that co-pilot Andreas Lubitz meant to destroy the Germanwings A320.
French and German investigators are still trying to figure out why. All 150 people aboard Flight 9525 from Barcelona to Duesseldorf were killed in the March 24 crash, which has been a reminder of the trust that passengers place in pilots.
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. The Flight Data Recorder records aircraft parameters such as the speed, altitude, and actions of the pilot on the commands.
Recording from the plane's other black box - the cockpit voice recorder - previously indicated that Lubitz locked the pilot out of the cockpit and deliberately crashed the plane, investigators have said.
Mountain officers and trained dogs are continuing to search the crash site. When the terrain is fully cleared of body parts and belongings, a private company will take out the large airplane debris.
Hundreds of victims' relatives have traveled to the region, officials say.
French Interior Minister Bernard Cazeneuve, visiting the area Friday in a visibly somber mood, praised residents who opened up their homes to grieving relatives as well as police and others behind the often-jarring recovery efforts.
"No one is ever prepared to face such an event," he said. "And yet immediately, a show of solidarity got organized - one of an entire region, the beautiful solidarity of people from the mountains; the one also through the state services."
Separately Friday, the Paris prosecutor's office announced it is looking into claims that information from the earliest phase of investigation into the crash was wrongly leaked to the media.
The prosecutor's probe follows a lawsuit filed last week by SNPL, France's leading pilots union over the leaks. The suit doesn't name an alleged perpetrator, a method in French law that leaves investigators to determine who is at fault.
The union is claiming a violation of French law about keeping information secret about ongoing investigations. Many pilots fear that details about the crash could damage public trust in an industry whose image has already been jolted by a string of recent incidents, like the mysterious disappearance of Malaysia Airlines Flight 370 a year ago.
Lubitz, 27, 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 say Lubitz's medical records, from before he received his pilot's license, had referred to "suicidal tendencies." Lufthansa, Germanwings' parent company, said it knew six years ago that he had had an episode of "severe depression" before he finished his flight training.
Marseille prosecutor Brice Robin says his investigation is focusing on France for now, but he has filed a formal request for judicial cooperation from Germany that could expand the scope of his probe.
He said French investigators believe that Lubitz was conscious until the moment of impact, and appears to have acted repeatedly to stop an excessive speed alarm from sounding.
"It's a voluntary action that guided this plane toward the mountain, not only losing altitude but correcting the aircraft's speed," he said Thursday.
Alice Coldefy, the mountain rescue officer who found the data recorder, described her unexpected discovery in a spot that had already been repeatedly searched.
"I found a pile of clothes, we were searching it, we were moving them downhill and while doing this I discovered a box. The color of the box was the same as the gravel, of the black gravel, that is everywhere at the crash site," she told reporters in Seyne-les-Alpes.
So-called black boxes are actually orange, but this one had burned up in the crash and blended with the dark earth covering the area, known to local guides as "the black lands."
"I didn't realize I had found it and I wasn't thinking it was possible to find it among all this debris," she said.