Composite aircraft

"Composite aircraft" can also refer to aircraft made using composite materials.

A composite aircraft is made up of multiple component craft. It takes off and flies initially as a single aircraft, with the components able to separate in flight and continue as independent aircraft.

Design principles

The composite configuration is usually adopted to provide increased performance for one of the components, compared to a single craft flying alone. The craft carrying out the operational mission need not be compromised by the requirements for takeoff, climb and initial cruise, but may be optimised for the later stages of the mission. In some variants, small parasite aircraft are provided in support of the main component.

One composite form comprises a large carrier^[1] aircraft or mothership^[2] and one or more small parasite^[2] or jockey^[3] craft carried either above or beneath the larger craft.

Another form comprises a small piloted component coupled with a larger unpiloted component, typically used as an attack aircraft.

The slip-wing composite is a theoretical variant comprising a lightweight upper lifting component, the slip wing, which assists the lower operational component during initial takeoff and climb: in the true slip-wing, the two wings act together as a biplane. The slip wing component may or may not be powered and/or manned.

History

Airship-planes

During and after World War I, a number of efforts were made to develop airship-plane composites, in which one or more aeroplanes were carried by an airship.

The first British effort, undertaken in 1916 with a non-rigid SS type airship, was aimed at the anti-Zeppelin role. The airship was to provide fast climb to altitude, while a B.E.2c aeroplane would provide the speed and manoeurvability to attack the Zeppelin. It ended in disaster when the forward attachment point released prematurely and the aeroplane tipped nose-down. Both crew were killed in the ensuing disaster. By 1918 larger rigid airships were available and a Sopwith Camel was successfully released, but the armistice halted work. The idea was briefly revived in 1925 when the airship R33 was used to launch and then recapture a D.H.53 and, in 1926, two Gloster Grebes.

In America the airships Akron and Macon routinely launched and recovered up to four purpose-built F9C Sparrowhawk reconnaissance fighters at a time between 1931 and 1935.

The first composite aeroplanes

In parallel with airship activity, further efforts went into carrying a fighter plane aloft on top of a second aeroplane.

In the UK, the Felixstowe Porte Baby/Bristol Scout composite flew in May 1916. The idea was to intercept German Zeppelin airships far out to sea, beyond the normal range of a land or shore based craft. The successful first flight was not followed up, due to the ungainliness of the composite in takeoff and its vulnerability in flight. From 1921, a series of types were adapted as carriers for gliders used in the aerial target role. The Short Mayo Composite mailplane made successful experimental (including cross-Atlantic) flights in the 1930s before operations were cut short by the outbreak of war.

World War II

The Tupolev Vakhmistrov Zveno project developed a series of composite types ^[2]. The SPB variant, having dive-bombers as the secondary components, saw successful operation.

In the UK, Pemberton-Billing proposed "slip-wing" composite bomber and fighter types, early in the war ^[4]. Hawker's also worked on a Liberator/Hurricane composite ^[5].

In 1943 O.A. Buettner patented a composite design in which the secondary fighter components' wings fitted into depressions in the carrier's upper wing^[6].

A number of composites proposals were considered by German designers during World War II ^[7]. Of these, only the Mistel composite reached operational status, and flew a number of combat missions.

Postwar

Experiments with parasite aircraft continued into the jet age, especially in America, and immmediately post-war, in France as well for their own advanced jet and rocket-powered experimental designs.

In modern times the term "composite aircraft" tends to refer to types constructed from composite materials. The White Knight/Space Ship One spaceplane is a composite aircraft in both senses.

References

Notes

1. ^ Flight 1946
2. ^ ^{a b c} Winchester, J. (Ed.); Concept aircraft, Grange, 2005
3. ^ Flight 1960
4. ^ Pemberton-Billing, The slip-wing fighter, Flight Dec 26, 1940, pp.524-525, 550-553
5. ^ Norris, G.; The Short Empire boats, No.84, Profile publications, 1966
6. ^ adventurelounge.com
7. ^ Flight, July 18th 1946, p.65

Bibliography

• Harper, H.C.J.; Composite history, Flight, November 11 1937. [1][2][3]
• Winchester, J. (Ed.); Concept aircraft, Grange, 2005

See also

• Parasite aircraft