The view from inside a Pilatus B-4 sailplane, just south of Osceola, Wisconsin, August, 2016. The Pilatus is a medium perform single seat Swiss glider; this one was made in 1972. Typically towed to 3000 feet (914 meters), it stayed up on rising air, such as found below the cumulus clouds shown. While general (non-commercial, non-military) aviation declined in America after gasoline prices rose, it remained a sport practiced by people.