Hafner Rotabuggy
Encyclopedia
The Hafner Rotabuggy (formally known as the Malcolm Rotaplane) and as the "M.L. 10/42 Flying Jeep" was a British
experimental aircraft
that was essentially a Willys MB
combined with a rotor kite
, developed with the intention of producing a way of air-dropping off-road vehicles.
of the Airborne Forces Experimental Establishment (AFEE) after their development of the Rotachute enjoyed some success.
The prototype was built by the R. Malcolm Ltdlater M L Aviation at White Waltham
in 1942. Air Ministry specification 10/42 for a "Special Rotating Wing Glider" was used to indentify the project.
Initial testing showed that a Willys MB could be dropped from heights up to 2.35 metres (7.7 ft) without damage to the vehicle. A 12.4 metre diameter rotor
was attached, along with a tail fairing and fin
s, but no rudder
s. Two men were required to pilot the aircraft: one to drive it as an automobile, and one to pilot it in the air using a control column. Initially it was named the "Blitz Buggy", but that was soon dropped for the "Rotabuggy".
The first trial was conducted on 16 November 1943, with the unit being towed behind a Diamond T
lorry
, but the lorry could not get enough speed to put the Rotabuggy in the air. A more powerful vehicle, a supercharged
4.5 litre Bentley
automobile, was used on 27 November to finally allow the machine to become airborne and in test could obtain glide speeds of 45 mph. Later tests were made towed behind an Armstrong-Whitworth Whitley bomber.
Although initial tests showed that the Rotabuggy was prone to severe vibration at speeds greater than 45 miles per hour (72 km/h), with improvements the Rotabuggy achieved a flight speed of 70 mph (113 km/h) on 1 February 1944. The last test flight occurred in September 1944, where the unit flew for 10 minutes at an altitude
of 400 feet (121.9 m) and a speed of 65 mph (105 km/h), after being released by a Whitley bomber, and was described as "highly satisfactory". However, the introduction of gliders
that could carry vehicles (such as the Waco Hadrian
and Airspeed Horsa
) made the Rotabuggy superfluous and further development was cancelled.
A replica of the Rotabuggy can be found at the Museum of Army Flying
. Hafner also came up with the idea of a similarly outfitted "Rotatank" using a Valentine tank
, but that was never built.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
experimental aircraft
Experimental aircraft
An experimental aircraft is an aircraft that has not yet been fully proven in flight. Often, this implies that new aerospace technologies are being tested on the aircraft, though the label is more broad....
that was essentially a Willys MB
Willys MB
The Willys MB US Army Jeep and the Ford GPW, were manufactured from 1941 to 1945. These small four-wheel drive utility vehicles are considered the iconic World War II Jeep, and inspired many similar light utility vehicles. Over the years, the World War II Jeep later evolved into the "CJ" civilian...
combined with a rotor kite
Rotor kite
A rotor kite or gyroglider is an unpowered, rotary-wing aircraft. Like an autogyro or helicopter, it relies on lift created by one or more sets of rotors in order to fly...
, developed with the intention of producing a way of air-dropping off-road vehicles.
Design and development
It was designed by Raoul HafnerRaoul Hafner
Raoul Hafner, , was an Austrian-born British helicopter pioneer and engineer.Raoul Hafner, FEng, FRAes, a pioneer of rotating wing aircraft design, died as a result of a yachting accident, was an Austrian who made a distinctive contribution to the British aerospace industry, particularly the...
of the Airborne Forces Experimental Establishment (AFEE) after their development of the Rotachute enjoyed some success.
The prototype was built by the R. Malcolm Ltdlater M L Aviation at White Waltham
White Waltham
White Waltham is a village and civil parish, west of Maidenhead, in the Royal Borough of Windsor and Maidenhead in the English county of Berkshire. It has a population of 2,875, and is the location of White Waltham Airfield.-Extent:...
in 1942. Air Ministry specification 10/42 for a "Special Rotating Wing Glider" was used to indentify the project.
Initial testing showed that a Willys MB could be dropped from heights up to 2.35 metres (7.7 ft) without damage to the vehicle. A 12.4 metre diameter rotor
Helicopter rotor
A helicopter main rotor or rotor system is a type of fan that is used to generate both the aerodynamic lift force that supports the weight of the helicopter, and thrust which counteracts aerodynamic drag in forward flight...
was attached, along with a tail fairing and fin
Fin
A fin is a surface used for stability and/or to produce lift and thrust or to steer while traveling in water, air, or other fluid media, . The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man-made devices...
s, but no rudder
Rudder
A rudder is a device used to steer a ship, boat, submarine, hovercraft, aircraft or other conveyance that moves through a medium . On an aircraft the rudder is used primarily to counter adverse yaw and p-factor and is not the primary control used to turn the airplane...
s. Two men were required to pilot the aircraft: one to drive it as an automobile, and one to pilot it in the air using a control column. Initially it was named the "Blitz Buggy", but that was soon dropped for the "Rotabuggy".
The first trial was conducted on 16 November 1943, with the unit being towed behind a Diamond T
Diamond T
The Diamond T was an American automobile manufactured in Chicago from 1905 until 1911 by the Diamond T Motor Car Company. It was a powerful touring car . The company later became known for its trucks...
lorry
Lorry
-Transport:* Lorry or truck, a large motor vehicle* Lorry, or a Mine car in USA: an open gondola with a tipping trough* Lorry , a horse-drawn low-loading trolley-In fiction:...
, but the lorry could not get enough speed to put the Rotabuggy in the air. A more powerful vehicle, a supercharged
Supercharger
A supercharger is an air compressor used for forced induction of an internal combustion engine.The greater mass flow-rate provides more oxygen to support combustion than would be available in a naturally aspirated engine, which allows more fuel to be burned and more work to be done per cycle,...
4.5 litre Bentley
Bentley
Bentley Motors Limited is a British manufacturer of automobiles founded on 18 January 1919 by Walter Owen Bentley known as W.O. Bentley or just "W O". Bentley had been previously known for his range of rotary aero-engines in World War I, the most famous being the Bentley BR1 as used in later...
automobile, was used on 27 November to finally allow the machine to become airborne and in test could obtain glide speeds of 45 mph. Later tests were made towed behind an Armstrong-Whitworth Whitley bomber.
Although initial tests showed that the Rotabuggy was prone to severe vibration at speeds greater than 45 miles per hour (72 km/h), with improvements the Rotabuggy achieved a flight speed of 70 mph (113 km/h) on 1 February 1944. The last test flight occurred in September 1944, where the unit flew for 10 minutes at an altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
of 400 feet (121.9 m) and a speed of 65 mph (105 km/h), after being released by a Whitley bomber, and was described as "highly satisfactory". However, the introduction of gliders
Military glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...
that could carry vehicles (such as the Waco Hadrian
Waco CG-4
The Waco CG-4 was the most widely used United States troop/cargo military glider of World War II. It was designated the CG-4 by the United States Army Air Forces, and named Hadrian in British military service....
and Airspeed Horsa
Airspeed Horsa
The Airspeed AS.51 Horsa was a British World War II troop-carrying glider built by Airspeed Limited and subcontractors and used for air assault by British and Allied armed forces...
) made the Rotabuggy superfluous and further development was cancelled.
A replica of the Rotabuggy can be found at the Museum of Army Flying
Museum of Army Flying
The Museum of Army Flying is an award-winning British military aviation museum about the history of flying in the British Army. It is located beside the Army Air Corps Centre in Middle Wallop, close to Andover in Hampshire, England....
. Hafner also came up with the idea of a similarly outfitted "Rotatank" using a Valentine tank
Valentine tank
The Tank, Infantry, Mk III, Valentine was an infantry tank produced in the United Kingdom during the Second World War. More than 8,000 of the type were produced in 11 different marks plus various purpose-built variants, accounting for approximately a quarter of wartime British tank production...
, but that was never built.
Specifications
- Gross weight: 1,411 kg (Willys MB: 964 kg; rotor unit and tail: 249 kg)
- Maximum speed: 241 km/h
- Estimated rates of descent: 4.9 m/s to 10 m/s
- Minimum take-off and landing speed: 58 km/h
- Sea level rotor speed: 230 rpm (basic), 260 rpm (max)