The Bensen B-8 is a small, single-seat

autogyro An autogyro (from Greek and , "self-turning"), gyroscope, gyrocopter or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. A gyroplane "means a rotorcraft whose rotors are not engine-d ...

developed in the United States in the 1950s. Although the original manufacturer stopped production in 1987, plans for homebuilders are still available as of 2019. Its design was a refinement of the

Bensen B-7 The Bensen B-7 was a small rotor kite developed by Igor Bensen in the United States in the 1950s and marketed for home building. It was a refined to be a slightly larger version of the B-6, replacing the skids with a tricycle undercarriage, and ...

, and like that aircraft, the B-8 was initially built as an unpowered

rotor-kite A rotor kite or gyrokite is an unpowered, rotorcraft, rotary-wing aircraft. Like an autogyro or helicopter, it relies on lift (force), lift created by one or more sets of helicopter rotor, rotors in order to fly. Unlike a helicopter, gyrokites ...

. It first flew in this form in 1955, and on 6 December a powered version, designated B-8M (M for motorised) first flew. The design proved to be extremely popular and long-lasting, with thousands of sets of plans sold over the next thirty years.

Design and development

The B-8's design is extremely minimalist, with not much more to the aircraft than a pilot's seat, a single tailfin, a rotor, and (in powered versions) the powerplant. In May 1968 a B-8 and B-8M were studied by the

USAF The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

under the Discretionary Descent Vehicle (DDV) program as the X-25B and X-25A respectively. In this scheme, it was proposed to integrate combat aircraft

ejection seat In aircraft, an ejection seat or ejector seat is a system designed to rescue the aircraft pilot, pilot or other aircrew, crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an exp ...

s with a small autogyro or rotor kite to allow downed pilots more control over their post-ejection landing spot. The X-25A and X-25B were used to evaluate the piloting and training requirements of the autogyros. No full-scale operational tests were ever performed. The U.S. Air Force stopped funding the DDV program with the end of the

Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...

.Jenkins et al
AMERICAN X-VEHICLES, X-25
''

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

'', June 2003. Accessed: 18 February 2012. One B-8M, named ''Spirit of Kitty Hawk'' (registration ''N2588B'') was used to make a special commemorative flight exactly duplicating the first flight of the

Wright brothers The Wright brothers, Orville Wright (August 19, 1871 – January 30, 1948) and Wilbur Wright (April 16, 1867 – May 30, 1912), were American aviation List of aviation pioneers, pioneers generally credited with inventing, building, and flyin ...

' original Flyer on the sixtieth anniversary of the occasion. This same aircraft was flown by

Igor Bensen Igor Vasilevich Bensen (; April 1, 1917 – February 10, 2000) was a Russian-American engineer. He founded Bensen Aircraft, a US company which produced a successful line of gyrogliders (rotor kites) and autogyros. Early life and educatio ...

himself between May 1967 and June 1968 to set twelve world and US speed, distance, and altitude records for autogyros, the largest number of such records to be held by any non-military rotorcraft.

Variants

* B-8 Gyro-Glider - unpowered rotor-kite intended to be towed behind a car * B-8B Hydro-Boat - B-8 with a full boat hull intended to be towed behind another boat * B-8M Gyro-Copter - standard motorised version, main production type. Usually powered by a McCulloch 4318 engine ** B-8MH Hover-Gyro - twin, coaxial rotor design with powered lower rotor and autorotating upper rotor, giving it the capability of hovering. Upper rotor and drive propeller powered by separate engines ** B-8MJ Gyro-Copter - B-8M modified for "jump" take off by a small second engine providing power to rotor head with anti-torque provided by rudder correction under power. X-25

** B-8MW Hydro Copter - float-equipped B-8M ** X-25A - B-8M evaluated by USAF. Single example (serial ''68-10770'') first flown 5 June 1968 and preserved at the

National Museum of the United States Air Force The National Museum of the United States Air Force (formerly the United States Air Force Museum) is the official museum of the United States Air Force located at Wright-Patterson Air Force Base, northeast of Dayton, Ohio. The NMUSAF is ...

Wright-Patterson Air Force Base Wright-Patterson Air Force Base (WPAFB) is a United States Air Force base and census-designated place just east of Dayton, Ohio, in Greene County, Ohio, Greene and Montgomery County, Ohio, Montgomery counties. It includes both Wright and Patte ...

* B-8 Super Bug - similar to B-8M but with extra engine to spin up rotor before take-off ** B-8HD Super Gyro-Copter - development of Super Bug first flown in 1979 with hydraulic drive to pre-rotate rotor rather than separate engine * B-8V - B-8 powered by a Volkswagen air-cooled engine * B-8W Hydro-Glider - float-equipped B-8 intended to be towed behind a boat * X-25B - B-8 evaluated by USAF. Single example (serial ''68-10771'') first flown 23 January 1968 and preserved at the AFFTC Museum at

Edwards Air Force Base Edwards Air Force Base (AFB) is a United States Air Force installation in California. Most of the base sits in Kern County, California, Kern County, but its eastern end is in San Bernardino County, California, San Bernardino County and a souther ...

. * Rotorcraft Minicopter Mk 1 - South African variant with pre-rotator and cockpit fairing. * Aeroflyte DGH-1 - license-built model from Aeroflyte.

Aircraft on display

* US Southwest Soaring Museum * New England Air Museum * North Carolina Museum of HistoryLewis, Rebecca, (2003
Flight of the Imagination
North Carolina Museum of History, Office of Archives and History, N.C. Department of Cultural Resources, retrieved 4 September 2013

Specifications (Typical B-8M, standard rotor)

References

Notes

External links

FAI records set by Igor Bensen in B-8M

Plans for B8
{{X-planes 1950s United States sport aircraft Rotor kites Single-engined pusher autogyros Homebuilt aircraft B-08 Aircraft first flown in 1955