Parasite aircraft

A parasite aircraft is an aircraft which is carried, and air launched by, a mother ship aircraft.

The first use for parasite aircraft was in 1916, when the British used a Bristol Scout, flying from a Felixstowe Porte Baby, a giant flying boat of its time. This eventually developed into modern jet bombers carrying fully capable fighter aircraft. In some cases, these aircraft are able to return to their mothership. As fighter capabilities increased, this role was seen as less and less necessary.

Other uses include launching spacecraft, experimental aircraft, and manned and unmanned reconnaissance aircraft.

Parasite fighters

A parasite fighter is a fighter aircraft intended to be carried into a combat zone by a larger aircraft, such as a bomber. If the bomber were threatened, it would be able to release the parasite to defend itself. Parasite fighters have never been highly successful and have seldom been used in combat. Projects for this type were designed to overcome the great disparity in range between bombers and their escort fighters. Apart from the fact that none of these schemes worked particularly well, aerial refuelling has done away with the need for such schemes.

The first parasite fighters were carried aboard military airships. As early as 1918, the Royal Air Force launched Sopwith Camel fighters from HM Airship 23, and tried again with Gloster Grebes on the R.33 in 1925. The "Imperial Airship" Programme" of 1924 envisaged a commercial airship that could also carry five fighter aircraft as well as troops if put into military use but the military usage was dropped and only civilian use retained. [http://www.aht.ndirect.co.uk/airships/imperial/index.html] . In the following decade, two U.S. Navy airships, USS "Akron" and "Macon" were designed with parasite fighter capability. Although operations with F9C Sparrowhawks were quite successful, the loss of both airships in crashes put an end to this programme.

The first bombers to carry parasite fighters did so as part of Zveno experiments carried out in the Soviet Union by Vladimir Vakhmistrov from 1931. Up to five fighters of various types were carried by Tupolev TB-2 and TB-3 bombers. One of these combinations would fly the only combat mission ever undertaken by parasite fighters when a TB-2 carrying Polikarpov I-16SPB dive bombers attacked the Cernavodă bridge in Romania in 1941.

Later in World War II, the "Luftwaffe" experimented with the Messerschmitt Me 328 as a parasite fighter, but problems with its pulsejet engines could not be overcome. Other late-war rocket-powered projects such as the Arado E.381 and Sombold So 344 never left the drawing board.

During the early years of the Cold War, the United States Air Force experimented with a variety of parasite fighters to protect its Convair B-36 bombers, including the dedicated XF-85 Goblin, and methods of either carrying a F-84 Thunderjet in the bomber's bomb bay (the FICON project), or attached to the bomber's wingtips (Project Tom-Tom). These projects were all soon abandoned, partly because air refueling appeared as a much safer solution to extend the range of fighters.

Commercial uses

In the 1930s, the parasite approach was tried as a means to give extra range to an aircraft. The Short Mayo Composite comprised a large flying boat with a smaller seaplane on its back. The flying boat would take the seaplane to the edge of its own range then the seaplane would separate and continue to the destination. In practice this combination was able to take mail from the UK to South Africa.

Research aircraft

The use of the parasite principle allowed for aircraft to be used where they would otherwise be unable to take off under their own power either because of limitations on powerplant or design (North American X-15)

Example of parasitic aircraft combinations

Famous examples include (but are not restricted to):

*Porte Baby/Bristol Scout, the first parasite aircraft (1916)
* L 35 (LZ 80)/Albatros D.III, the first parasite fighter flying from an airship (January 26, 1918)
* HMA 23/Sopwith Camel, parasite fighter, flying from an airship (1918)
* Tc-3 and Tc-7 non-rigid airship launched and recovered a Sperry Messenger biplane (1923)
* Royal Air Force Trials of DH 53 Hummingbird light planes launched and recoverd by the airship R33 (1924), followed by equipping the airship with two Gloster Grebe fighters (1925).
* USS "Akron" and "Macon"/F9C Sparrowhawk, a very successful U.S. Navy escort fighter program, ended when the airships crashed (1935)
*Short S.21/Short S.20, "Short-Mayo Composite" a flying-boat/seaplane combination for transoceanic postal service (1938)
* Tupolev TB-3/Polikarpov SPB, the first parasite aircraft to see combat (1941)
* Dornier Do 217/Messerschmitt Me 328, escort fighter, unsuccessful due to engine problems
* B-36/XF-85 Goblin, an attempt to equip bombers with their own escort fighters (1948)
* B-36/F-84, another, more successful, escort fighter attempt (1952)
* DC-130/Q-2C Firebee, drone launched and controlled from C-130 "mother"
* Lockheed D-21/M-21, for high-speed reconnaissance, based upon the SR-71 Blackbird (1963)

Gallery

See also

* Airborne aircraft carrier
* Captive carry
* FICON project
* Mistel - German WWII project in which a piloted fighter aimed, then released, a pilotless ('bunker-buster') bomber with an explosive warhead in its nose
* Zveno project

External links

* [http://aeroweb.lucia.it/rap/RAFAQ/Zveno.html Pre World War II Russian parasite fighters]
* [http://www.geocities.com/usarmyaviationdigest/airborneaircraftcarriers.htm pictures of parasites]
* [http://www.airpower.maxwell.af.mil/airchronicles/apj/apj05/sum05/kramlinger.html Recent article advocating parasite aircraft]
* [http://www.youtube.com/watch?v=R7gdbCVu3_M Video including XF-85 Goblin in flight and FICON aircraft]