Andreas Lubitz, the Germanwings co-pilot who prosecutors say may have deliberately crashed a plane into the Alps on Tuesday killing 150 people, was described by acquaintances in his hometown of Montabaur as a "normal guy" and "nice young man".
"He was a completely normal guy," Klaus Radke, the head of the local flight club where Lubitz received his first flying licence years ago. He returned in the fall for a refresher course with Radke.
"I got to know him, or I should say reacquainted with him, as a very nice, fun and polite young man," Radke added.
The small town of 12,000 in western Germany was in shock on Thursday at the news that French prosecutors suspect Lubitz, 28, of deliberately crashing the Airbus plane.
German authorities were at loss to explain why the first officer for Lufthansa's budget carrier appeared to have taken sole control of the A320 airliner when the captain was out of the cockpit and slammed it into a fatal descent.
Lubitz had no known association with terrorist groups, said German Interior Minister Thomas de Maiziere.
He appeared to have led an active lifestyle, running a half-marathon in a good time and showing an interest in pop music and night-clubs, according to his Facebook page, which also featured a photo of Lubitz by the Golden Gate Bridge in San Francisco.
"I'm just speechless. I don't have any explanation for this. Knowing Andreas, this is just inconceivable for me," said Peter Ruecker, a long-time member of the flight club who knew Lubitz well.
"Andreas was a very nice young man who got his training here and was a member of the club," Ruecker said. "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."
Near the small, white house in the town where Lubitz lived and where police quickly set up guard, neighbor Hans-Juergen Krause said he was "really shocked" by the news.
Armin Pleiss, head teacher of the Mons-Tabor-Gymnasium high school where Lubitz graduated in 2007, told Reuters: "I am just as shocked and surprised as you are." Lubitz attended the school of 1,300 students before Pleiss became the principal.
Germanwings has so far given only sketchy biographical details of the co-pilot, who had only 630 hours of flying time to his name, unlike the captain who had flown for more than 6,000 hours and had worked for Lufthansa for 10 years.
Lubitz was trained at the Lufthansa pilot training academy in Bremen, which declined to talk about him. His local flight club carried a black ribbon on its website with the flight number and the name "Andreas".
"He had a lot of friends, he wasn't a loner," said Ruecker.
"He was integrated in the group. Our club is mostly made up of young people who learn how to fly gliders and then get their licence and then perhaps, like was the case with him, to make the jump into commercial aviation."