The flight's co-pilot, Andreas Lubitz, is believed to have deliberately crashed the aircraft after having locked the captain out of the cockpit, French prosecutor Brice Robin said in a press conference on Thursday. All 150 people on board the flight from Barcelona to Düsseldorf were instantly killed.
The prosecutor did not identify the captain by name. A spokeswoman for Lufthansa, the parent company of Germanwings, told BuzzFeed News that the airline would not confirm the identity of the captain "out of respect for his privacy."
Europe1, a French radio station, interviewed a former colleague of the captain, who said that the pilot had a lot of experience and was well-regarded among his co-workers. The radio station did not name Sonderheimer, but refer to him as "the commander" of Airbus.
"He was one of our best pilots," said the former colleague, identified only as dieter. "I'm 100% sure that he did everything he could. I knew him very well. He had a lot of experience, more than 6,000 of flight. He was a very good man, he had a great sense of humor."
Dieter, the captain's colleague, said that the pilot was married and had two small children.