The Glaser-Dirks DG-500, and later the DG-505, is a two-seat glider of glass-reinforced plastic and carbon fiber reinforced plastic construction, manufactured in the DG Flugzeugbau GmbH in Bruchsal, G

The Windward Performance Perlan 2 is an American mid-wing, two-seats-in-tandem, pressurized, experimental research glider that was designed by Greg Cole and built by Windward Performance for the Perla