The Cornelius XFG-1 was an American military fuel transporting towed glider, without a tailplane and with a forward-swept wing.

[2] His first two machines were otherwise conventional but the third, the Cornelius Mallard from 1943 was not, being without a horizontal tailplane and having low aspect ratio and strongly forward swept wings.

[4][5] Unlike other troop carrying gliders, e.g. Waco CG-4, the XFG-1 could be towed by modern bombers or transports at a cruise speed of 250 mph (220 kn; 400 km/h).

Proposals seem to have included a piloted tow version behind a large transport, the glider landing loaded on skids having jettisoned its wheels after takeoff; or a pilot-less version towed behind a B-29 bomber, disconnected and abandoned after fuel transfer was completed;[2][3] the intent of the scheme being for the glider to act, essentially, as a giant, winged drop tank for extending the range of the towing aircraft.

It had a simple fixed tricycle undercarriage and a conventional single seat cockpit; two examples of the type were built.