| Hafner Rotachute | |
|---|---|
 | |
| Ground test of a Rotachute III at Ringway, 1942 | |
| Role | manned rotor kite |
| National origin | UK |
| Designer | Raoul Hafner |
| First flight | 1942 |
| Produced | 1942 |
| Number built | c. 8 |
The Hafner H.8 Rotachute was a British 1940s experimental one-man rotor kite designed by Raoul Hafner.
The Rotachute was the eventual development of a concept devised by Raoul Hafner, an Austrian engineer who specialised in rotary wing design, and who had moved to the UK in 1933 to continue his research and development work. In 1940, he proposed the use of a single-place strap-on rotor kite in place of a conventional parachute, to deliver a soldier accurately to a battlefield. The proposal was made to the Air Ministry in the light of a shortage of silk for parachute manufacture. Hafner was briefly interned as an alien, but was released to pursue the feasibility of the idea at the Central Landing Establishment (CLE) located at RAF Ringway. In October 1940, work began on design and construction of rotor systems and scale models of rotor kites. The first models were made of wood and fabric, ballasted to represent a pilot, and had a rotor span of about 3 ft (0.91 m). They were tested successfully by hand launching, but suffered buffeting and lack of autorotation when launched from aircraft at height. The third evolution, designated "M.3", had metal rotor blades, and after further modifications made the first successful launch and descent from a De Havilland Tiger Moth. Further developments and tests continued into February 1941. The tenth evolution scale model (M.10) had mass-balanced wooden rotors, ballast of 100 lb (45.3 kg), and a rotor span of 10 ft (3.05 m). On 14 March 1941, the M.10 model was successfully air-launched from a Boulton & Paul Overstrand. [1] [2]
The design of the man-carrying machine known as a Rotachute, also known as a Hafner H.8, evolved from November 1940 and throughout 1941. In September 1941, the Central Landing Establishment was renamed the Airborne Forces Establishment. The Rotachute Mark I design initially comprised a tubular steel framework with a single seat, rubber-mounted rotor hub, hanging control column, skid undercarriage, and a self-inflating rear fairing made of rubberised fabric with integral tailplane. The two rotor blades, of wooden construction, could achieve flapping and coning characteristics via hinges on the rotor hub. Fixed footrests were provided, plus fittings below the seat to accommodate a soldier's weapon, such as a Bren gun. The control column offered two-axis control, rolling and pitching, with turns made via controlled rolling movement. Air Ministry Specification No. 11/42 was issued retrospectively to describe the outline requirements. The Ministry of Aircraft Production sub-contracted construction of parts to specialist firms including F. Hills and Sons, Airwork General Trading, Dynaflex, Dunlop, and H. Morris & Co. Some full size rotor trials were carried out using a pivoting rig mounted on a Ford flatbed truck, and full-size unmanned airframes were used in ground-based and inflight trials. [1] [2]
In January 1942, trials of the Rotachute Mark I were conducted to assess the aerodynamic characteristics while on the truck-mounted rig, with pilot control of the aircraft in forward motion. On 11 February 1942, the prototype Rotachute was first manually flown from a wheeled trolley while under tow behind a Humber car at Ringway, after starting the rotor by hand. The pilot was Flt Lt I.M. Little, who had experience flying Avro/Cierva C.30 Rota autogiros on radar calibration duties; he was later awarded the Air Force Cross (UK). On that and on a subsequent trial, the machine rolled over after landing, sustaining damage to the blades but not to the pilot. A tethered test beneath a barrage balloon and a longer test flight at RAF Snaith were both more successful. The flexible tail section evidently offered inadequate directional stability, and the consequence was the Rotachute Mark II, that had a longer tail section braced with wooden formers, plus two landing wheels mounted below the centre of gravity. [1] [2]
On 15 February 1942, the unit was again reorganised, to form the Airborne Forces Experimental Establishment (AFEE), still based at Ringway. The rotary wing section of AFEE continued to conduct tests on longer runways during detachments at RAF Snaith and RAF Chelveston. On 29 May 1942, the first flight of the Rotachute Mark II was achieved while under tow behind a Jeep, and several more towed flights were also successful. Meanwhile, the Mark III had been produced, with a tail section comprising a wooden framework covered in doped linen fabric plus a rigid tailplane. Starting on 2 June 1942, the Rotachute Mark III was flown at heights up to 100 ft (30.5 m) while under tow behind a Jeep, with tow rope lengths up to 300 ft (91.4 m). From 9 June, successful inflight releases and landings were achieved while under tow. [1] [2]
From 17 June 1942, a Rotachute Mark III was air-towed behind a Tiger Moth on a 300 ft (91.4 m) tow line. After two towed flights, the Rotachute was released at an altitude of 200 ft (61 m) and made the first manned free flight and controlled landing. Further free flights were made from altitudes up to 3,900 ft (1,189 m). On 1 July 1942, AFEE moved its main base from Ringway to RAF Sherburn-in-Elmet. Additional directional stability was achieved in the Rotachute Mark IV, that introduced endplates onto the rigid tailplanes. [1] [2]
Although the Rotachute concept had proved to be practical, the operational requirement for such a machine never materialised. About eight Rotachutes were constructed, most being progressively converted to Mark III and then to Mark IV specifications. They continued to be flown in ground-based and inflight trials until late 1943, to help research flight characteristics for a follow-on project, the Hafner Rotabuggy, an air-towed land vehicle with autogiro capabilities. [1] [2]
The fifth aircraft (P-5) was a Rotachute Mark III, converted in 1943 to the Mark IV configuration, and is displayed at the Museum of Army Flying, Middle Wallop, in England. [3] [4]
Data from Jarrett 1991 [2]
General characteristics
Performance
An autogyro, or gyroplane, is a class of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. While similar to a helicopter rotor in appearance, the autogyro's unpowered rotor disc must have air flowing upward across it to make it rotate.
The Bristol Type 171 Sycamore is an early helicopter developed and built by the helicopter division of the Bristol Aeroplane Company. The name refers to the seeds of the sycamore tree, Acer pseudoplatanus, which fall with a rotating motion. It has the distinction of being the first British helicopter to receive a certificate of airworthiness, as well as being the first British-designed helicopter to be introduced by and to serve with the Royal Air Force (RAF).
Early flying machines include all forms of aircraft studied or constructed before the development of the modern aeroplane by 1910. The story of modern flight begins more than a century before the first successful manned aeroplane, and the earliest aircraft thousands of years before.
The General Aircraft GAL.48 Hotspur was a military glider designed and built by the British company General Aircraft Ltd during World War II. When the British airborne establishment was formed in 1940 by order of Prime Minister Winston Churchill, it was decided that gliders would be used to transport airborne troops into battle. General Aircraft Ltd were given a contract by the Ministry of Aircraft Production in June 1940 to design and produce an initial glider for use by the airborne establishment, which resulted in the Hotspur.
The Cierva C.30 is an autogyro designed by Juan de la Cierva and built under licence from the Cierva Autogiro Company by A V Roe & Co Ltd (Avro), Lioré-et-Olivier and Focke-Wulf.
The Saunders-Roe Skeeter is a two-seat training and scout helicopter that was developed and produced by British manufacturer Saunders-Roe ("Saro") of Cowes and Southampton, in the United Kingdom.
The Fairey Jet Gyrodyne is a British experimental compound gyroplane built by the Fairey Aviation Company that incorporated helicopter, gyrodyne and autogyro characteristics. The Jet Gyrodyne was the subject of a Ministry of Supply (MoS) research contract to gather data for the follow-up design, the Rotodyne.
The Bristol Type 173 was a British twin-engine, tandem rotor transport helicopter built by the Bristol Aeroplane Company. It was designed by Raoul Hafner as a civil transport helicopter but evoked interest from the military. It did not enter production but was developed into the Bristol Belvedere which was operated by the Royal Air Force from 1961 to 1969.
The General Aircraft GAL.56 was a family of 1940s British experimental tailless swept wing glider designs.
Royal Air Force Beaulieu or more simply RAF Beaulieu is a former Royal Air Force station in the New Forest, Hampshire, England. It was also known as Beaulieu airfield, Beaulieu aerodrome and USAAF Station AAF 408. It is located on Hatchet Moor 1 mile (2 km) west of the village of East Boldre, about 2 miles (3 km) west-southwest of the village of Beaulieu and 4 miles (6 km) north-east of Lymington.
The Kellett KD-1 is a 1930s American autogyro built by the Kellett Autogiro Company. It had the distinction of being the first practical rotary-wing aircraft used by the United States Army and inaugurated the first scheduled air-mail service using a rotary-wing aircraft.
Raoul Hafner, (1905–1980) FEng, FRAes, was an Austrian-born British helicopter pioneer and engineer. He made a distinctive contribution to the British aerospace industry, particularly in the development of helicopters.
The Hafner Rotabuggy 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.
A rotor kite or gyrokite 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. Unlike a helicopter, gyrokites and rotor kites do not have an engine powering their rotors, but while an autogyro has an engine providing forward thrust that keeps the rotor turning, a rotor kite has no engine at all, and relies on either being carried aloft and dropped from another aircraft, or by being towed into the air behind a car or boat or by use of ambient winds for the kiting. As of 2009, no country in the world requires a license to pilot such a craft.
The Bensen B-5 was a small rotor kite developed by Igor Bensen in the United States and offered and marketed for home building in 1954. Dubbed the "Gyro-Glider", it was the first of several such designs that would be sold by Bensen Aircraft Corporation over the following decades.
The Pitcairn PCA-2 was an autogyro developed in the United States in the early 1930s. It was Harold F. Pitcairn's first autogyro design to be sold in quantity. It had a conventional design for its day – an airplane-like fuselage with two open cockpits in tandem, and an engine mounted tractor-fashion in the nose. The lift by the four-blade main rotor was augmented by stubby, low-set monoplane wings that also carried the control surfaces. The wingtips featured considerable dihedral that acted as winglets for added stability.
The Autogiro Company of America AC-35 was an early attempt to make a roadable aircraft in the United States during the 1930s. Although it was successfully tested, it did not enter production; a 1960s attempt to revive the aircraft in a non-roadable version also failed to achieve success.
The Airborne Forces Experimental Establishment (AFEE) was a branch of the British Air Ministry, that researched and developed non-traditional airborne applications, such as gliders, rotary wing aircraft, and dropping of personnel and equipment by parachute, in the period 1942–1950.
The Westland CL.20 was a two-seat autogyro designed and built by Westland Aircraft between 1934 and 1938. One flying prototype and six airframes were built, which had control problems and insufficient lift. Before these problems could be solved the programme was abandoned and the prototype was scrapped in 1938.
Reginald Alfred Charles Brie MBE AFRAeS AFIAeS was a British rotorcraft test and demonstration pilot.