Family and relatives of the victims of the Germanwings plane crash in the Alps are taken on bus to the Prat airport from a hotel in Castelldefels in Barcelona, Spain, to take a Lufthansa flight to visit the crash site in Seyne les Alps in France, March 26, 2015. [Photo/IC]

"He was a lot of fun, even though he was perhaps sometimes a bit quiet. He was just another boy like so many others here."

A photo on Lubitz's Facebook page, which was later taken down, shows a smiling young man posing in front of San Francisco's Golden Gate bridge.

Investigators were still searching for the second of the two black boxes on Thursday in the ravine where the plane crashed, 100 km (65 miles) from Nice. This box would contain data from the plane's instruments.

Under German aviation law, pilots may temporarily leave the cockpit at certain times and in certain circumstances, such as while the aircraft is cruising.

Cockpit doors can be opened from the outside with a code, in line with regulations introduced after the Sept 11, 2001 attacks in the United States, but the code can be overridden from inside the cockpit, making the door impenetrable.

Germanwings said 72 Germans were killed in the first major air passenger disaster on French soil since the 2000 Concorde accident just outside Paris. Madrid revised down on Thursday the number of Spanish victims to 50 from 51.

As well as Germans and Spaniards, victims included three Americans, a Moroccan and citizens of Britain, Argentina, Australia, Belgium, Colombia, Denmark, Israel, Japan, Mexico, Iran and the Netherlands, officials said. However, DNA checks to identify them could take weeks, the French government said.

The families of victims were being flown to Marseille on Thursday before being taken up to the zone close to the crash site. Chapels had been prepared for them with a view of the mountain where their relatives died.