UPDATE: The latest details in the Germanwings crash

Germanwings crash scene (AFP/Denis Bois/Gripmedia/AFP TV)

Latest developments:

• One of the pilots on board Germanwings Flight 9525 was locked out of the cockpit when the plane crashed Tuesday, a senior military official told The New York Times, citing evidence from the cockpit voice recorder.
• Helicopters have airlifted some victims' remains from the site of the Germanwings plane crash in the French Alps, the Gendarmerie said Wednesday, according to CNN affiliate France 2.
• FBI agents based in France, Germany and Spain are looking through intelligence sources and cross-referencing the passenger manifest of Germanwings Flight 9525, two senior law enforcement officials said. So far, their search hasn't turned up anything that "stands out" or anything linking the passengers to criminal activity, according to one official.

The head of France's air crash investigation agency says "usable data" has been recovered from one of the black boxes of the Germanwings Airbus that crashed in the French Alps.

Black box from crashed Germanwings flight. (Reuters/BFA)

Investigators are scouring the pulverised debris of the German airliner for bodies and clues to its mysterious eight-minute descent and crash that killed all 150 aboard, including two Australians.

Hundreds of firefighters and police near the hamlet of Le Vernet launched a massive operation at the rugged crash site, accessible only by helicopter or by an arduous hike on foot.

Experts in Paris have begun analysing the first black box, which was recovered on Wednesday, for clues as to why the Germanwings Airbus A320 went down in good weather — an "inexplicable" disaster according to Lufthansa, the budget airline's parent company.

Remi Jouty, head of French air crash investigation agency BEA, said data had been recovered, but experts still had no explanation for the crash.

"We have just succeeded in extracting usable data from the cockpit voice recorder," he said.

"At this stage, clearly, we are not in a position to have the slightest explanation or interpretation on the reasons that could have led this plane to descend ... or the reasons why it did not respond to attempts to contact it by air traffic controllers."

Mr Jouty said he expected the first basic analysis in "a matter of days" but warned this reading could be subject to errors and that more work would be needed for a full interpretation.

Although he said "words" had been heard on the tape, Mr Jouty would not confirm whether that meant the Airbus A320's pilots were conscious and he gave no details of the recordings.

Every plane has two black boxes — one records data about the plane's operation and its position, while the other records the voices of the pilot and any other noises in the cockpit.

French president Francois Hollande said search and rescue teams had recovered the casing for the other black box, but not the box itself.

The plane

• French civil aviation authorities said they lost contact with the plane, an Airbus 320, at 10:30am
• Transponder data from the plane was last received by flightradar24 at 10:41am, when it was at an altitude of 6,800 feet
• Over the previous 10 minutes it descended from an altitude of 38,000 feet, according to flightdata24
• No mayday call was sent. Air traffic control declared the plane was in distress after they could not contact the crew

Airbus A320 (D-AIPX) of Germanwings taking off from Barcelona Airport. This aircraft crashed on 24 March 2015 in the French Alps as Germanwings Flight 9525. (By SEBASTIEN MORTIER, via Wikimedia Commons)

Tracking the Germanwings plane's altitude

The plane's altitude (in feet) from take-off to when its transponders stopped being picked by flight tracking website Flightradar24. (All times are local.)

31,500

0

10,000

20,000

30,000

38,000

10:00

10:02

10:05

10:08

10:11

10:14

10:17

10:20

10:23

10:26

10:30

10:33

10:36

10:41

Source: Flightradar24 (ABC News)

The crash site

• The debris has been found in a rugged area near the town of Le Vernet in the French Alps, about 100 kilometres from the coastal city of Nice
• Teams scouring the debris have had to be winched down by helicopters, which cannot land due to the terrain
• Local French MP Christophe Castaner, who flew over the site, said on Twitter: "Horrendous images in this mountain scenery. Nothing is left but debris and bodies. A horror - the plane is totally destroyed."
• The area saw another air disaster just over 50 years ago in 1953, when an Air France plane to Vietnam crashed near where flight 4U 9525 came down. The plane clipped a mountain and crashed into a rocky crevice just before midnight, killing 42 people on board.

Map: Germanwings flight 4U9525 crashed north-west of Nice in France, en route from Barcelona to Dusseldorf. (ABC News)

Clues in the debris
Investigators are still trying to piece together what caused the crash.

A screengrab taken from an AFP TV video on March 24, 2015 shows search and rescue personnel at the crash site of the Germanwings Airbus A320 in the French Alps. (AFP Photo: Denis Bois)

Jouty, the head of the investigation team, said the debris suggests the plane hit the ground and then broke apart, instead of exploding in flight.

Radar followed the plane "virtually to the point of impact" in the Alps in southern France, Jouty said. The flight's last altitude recorded by radar was just over 6,000 feet.

Officials have said that while they have not ruled out terrorism, it seems unlikely.

FBI agents based in France, Germany and Spain are looking through intelligence sources and cross referencing the passenger manifest of Germanwings Flight 9525, two senior law enforcement officials said. So far, their search hasn't turned up anything that "stands out" or anything linking the passengers to criminal activity, according to one official.


Using: ABC, CNN; with Wires, AFP and Reuters