I fly gliders recreationally. Last fall one of the guys in the club called me up and asked if I'd lost my GoPro. I hadn't, but from his description, it was probably the camera of a guy I flew a two-seater with in a competition a year earlier.
Turns out that the camera had been returned by a hiker who found it while hiking on a mountain, approximately 10 kilometers from the airfield. Looking at the last footage in the camera, you could see three guys using a suction cup holder to attach the camera on the outside body of the glider. The video continued as the glider launched, and for approximately ten minutes of flight. Then, the camera detatched from the airplane. As it went tumbling down, there were a couple of frames where the glider was captured from below, rapidly disappearing into the sky.
The camera landed on the mountain, where it remained through the winter. A year later, a guy hiking there found it and returned it, in working order, to the glider club.