A leading German pilots’ association expressed concern Friday with French authorities’ assertion that Germanwings Flight 9525 co-pilot Andreas Lubitz deliberately crashed the plane into the French Alps. Members of the group urged the public to take caution in drawing conclusions until all of the facts become clear.

“We should not rush to conclusions based upon limited data,” said Ilja Shulz, president of the German Airline Pilots Association, via the Independent. “The reasons that led to this tragic accident will only be determined after all data sources have been thoroughly examined.”

Lubitz, a 28-year-old from Montabaur, Germany, locked Flight 9525’s flight commander out of the cockpit during a bathroom break and altered the aircraft’s course with the intent to “destroy the plane,” French prosecutor Brice Robin said Thursday at a press conference. He added there was “absolute silence in the cockpit” and that attempts by air traffic controllers to contact the plane went unanswered. Prosecutors have not found any evidence to link Lubitz’s actions to terrorism, though Robin acknowledged questions about a possible pilot suicide were “legitimate.”

“It is a very, very incomplete picture,” James Phillips, the German pilots group’s international affairs director, told Time. “I have the feeling that there was a search for a quick answer, rather than a good answer.”

Lufthansa concluded, based on evidence prosecutors provided, that Lubitz deliberately crashed the plane, the German airline’s chief executive Carsten Spohr said at a press conference Thursday. Spohr said Lubitz took a six-month hiatus from pilot training in 2009, but later completed the required battery of physical and psychological tests and was deemed fit to serve.

“Six years ago there had been an interruption to his training. We checked his skills, his competence and he went back to training school. After that he was successful. He went through all of that with flying colors,” Spohr said. “He was fit in all areas, 100 percent.”

Lubitz’s former classmates and friends told German reporters he left training for six months due to struggles with depression. He received psychiatric care for a year, German newspaper Bild reports.

A search of Lubitz’s apartment in Düsseldorf uncovered evidence he suffered from a medical condition that he hid from Lufthansa. Authorities discovered torn-up sick notes in the apartment that would have excused him from work on the day of the crash, according to the Associated Press.