Bensen X-25A "Gyrocopter"

The gyroplane (or "gyrocopter" or simply "gyro") is a helicopter-airplane hybrid, offering many of the benefits of both and several of its own. Unlike a helicopter, the gyro's rotor blades are unpowered, necessitating a short roll for take-off. A major safety feature of the gyro is that if the engine fails, the craft can glide to a safe landing. Also, the gyro is less affected by high wind than typical fixed-wing aircraft and is not subject to stall. History was made in 1924 when Lt. Juan Gomez-Spencer made a flight in the world's first practical rotary-wing aircraft - the Cierva C.4. Pre-war autogiros (autogiro was a Cierva trade name) were massive aircraft that were expensive to purchase and operate, but they had considerable success in specialized roles such as mail delivery to central cities, news reporting, and the air-show circuit.

In the 1950s the Bensen Aircraft Corporation developed the novel "Gyrocopters" and "Gyrogliders." The B-7 Gyroglider, introduced in 1955, captured the public's imagination with its unprecedented simplicity of design and ease of flight. Although the B-7 had no engine and was towed into the air very much like a kite, shortly thereafter the engine-powered B-7M Gyrocopter was introduced. Bensen founded the Popular Rotorcraft Association in the 60's and his aircraft dominated the home-built rotorcraft movement into the early 1980's. The Bensen X-25 Discretionary Descent Vehicle [DRV], a revised version of the Bensen Aircraft standard B-8M gyrocopter, was tested as means for downed flyers to escape from enemy territory. The concept called for replacing the standard ejection seat with the DRV, which would enable a pilot forced to eject to fly away from the action in a controlled descent. Designed to operate like a rotorchute, following ejection and a brief period of decent, the DDVs rotor blades automatically self deployed and aerodynamic forces then rotated the blades. It came about as a result of a growing number of pilots being downed beyond the range of conventional rescue methods during the Vietnam War.

The basic X-25 was un-powered and of very basic construction, consisting of little more than an aluminium square cross sectioned structure with a single seat and four post landing gear. The X-25A & B were variations of Bensons McCulloch powered B-8M and un-powered B-8 Gyroglider. Although far more complex than the planned 'one use' DDV, the X-25A and B provided both the data required to prove the feasibility of the DDV concept. The X-25A first flew in May 1968 and was proven to be feasible, but production was never funded.