Bensen B-8M Gyro-Copter (AF designation X-25)


Description
Manufacturer: Bensen
Designation: X-25 (Air Force)
Version: B-8M
Nickname: Gyro-Copter, Gyro, Autogyro
Type: a push-propeller aircraft using a wind-powered propeller for lift
Specifications
Length: 11 ft.  4 in.
Height: 6 ft. 3 in.
Rotor Diameter 21 ft. 6 in.
Cost:  approx $2000
Gross Weight, max 550 lbs.
Gross Weight, empty: 247 lbs. empty
Propulsion
No. of Engines: 1
Powerplant: McCulloch 4318 piston engine
Horsepower (each): 72 hp (diff options ranged 65 to 90 hp)
Performance
Range: 84 miles in 1 hour and 25 minutes
Cruise Speed:  65 mph
Max Speed: 95 mph
Ceiling: 15,000 Ft


Powered autogyro versions of the auto-kites have been developed simultaneously, the first of these being the B-7M which flew for the first time on 6 December 1955. This was followed on 8 July 1957 by the first B-8M (M = motorised) and by the first production B-8M on 9 October 1957. The Gyro-Copter was a powered version of the Gyro-Glider. It was designed to be constructed from a set of plans costng about $30 or from a prefabricated kit, costing $995. Engines were available ranging in price from $495 to $1195. As few as forty manhours were required for kit assembly. It was designed by Igor Bensen, a Russian immigrant to the United States.  He had been a test pilot for both the Air Force and the Navy. His new company was formed to develop light, safe rotary-wing aircraft for use by private individuals.  Besides their use as a pleasure craft Gyro-Copters could be used for terrain and pipeline aerial surveillance and sport and forestry patrol. In England one was modified for crop spraying. All three branches of the military had several in their inventories.

The first aircraft produced by the Benson company were the Bensen B-7 and B-8 Gyro-Gliders, which were unpowered and could be flown without a pilot license in the United States. It could be built at home from a kit that an aspiring pilot would purchase from the company or could be purchased already assembled.  The "M" in the B-8M is for motorized.  The B-7 had no engine and was towed into the air very much like a kite. The B-8M is normally powered by a 72hp McCulloch piston engine. Optional features include a 90hp McCulloch engine and a mechanical rotor drive enabling the autogyro to make jump starts. A float version of the B-8M is known as the Hydro-Copter. The autogyro was a powered version of the Gyro-Glider and could fit in anyone's garage. The Model B-8M could also be converted from an aircraft to an automobile by simply locking its blades in place. On the road as an automobile it could achieve 35 mph. Production of the Gyrocopter continued until 1987.

The gyroplane (or "gyrocopter" or simply "gyro") is essentially a helicopter-airplane hybrid.  Unlike a helicopter, the gyro's rotor blades are unpowered, necessitating a short roll for take-off—unless the craft is fitted with a pre-rotator.

The museum's Benson B-8M was donated on January 19, 1991, by Adeline Weigandt of Huntington Beach, CA.. This aircraft is on loan from the USAF.

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