Parasite aircraft



A parasite aircraft is a component of a composite aircraft which is carried aloft and air launched by a carrier aircraft or mother ship to help or protect the carrier. The carrier craft may or may not be able to later recover the parasite during flight.

The first parasite aircraft flew in 1916, when the British launched a Bristol Scout from a Felixstowe Porte Baby flying boat. The idea eventually developed into jet bombers carrying fully capable parasite fighters. With the advent of long-range fighters equipped with air-to-air missiles, this role was seen as less and less necessary.

Parasite fighters
Until the middle of the 20th century there was military interest in parasite fighters - fighter aircraft intended to be carried into a combat zone by a larger aircraft, such as a bomber. If the bomber were threatened, the parasite would be released to defend it. Parasite fighters have never been highly successful and have seldom been used in combat. A major disadvantage of a parasite aircraft was that it reduced the payload capacity of the carrier aircraft. Projects for this type were designed to overcome the great disparity in range between bombers and their escort fighters. Development of aerial refueling has made parasite fighters obsolete.

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. On Dec 12, 1917, in a test to determine the feasibility of carrying fighter aircraft on dirigibles, the airship C-1 lifted a US Army JN-4 aircraft in a wide spiral climb to 2,500 feet over Fort Tilden, N.Y., and at that height released it for a free flight back to base. The airship was piloted by Lieutenant George Crompton, (Naval Aviator #100) Dirigible Officer at NAS Rockaway, and the plane by Lieutenant A. W. Redfield, USA, commanding the 52d Aero Squadron based at Mineola (Long Island, NY). In the following decade, two U.S. Navy airships, the USS Akron and the 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 the Zveno experiments carried out in the Soviet Union by Vladimir Vakhmistrov from 1931. Up to five fighters of various types were carried by Polikarpov TB-2 and Tupolev TB-3 bombers. In August 1941, these combinations would fly the only combat missions ever undertaken by parasite fighters. TB-3s carrying Polikarpov I-16SPB dive bombers attacked the Cernavodă bridge and Constantsa docks, in Romania. After that, this squadron, based in the Crimea, carried out a tactical attack on a bridge over the river Dneiper at Zaporozhye, which had been captured by advancing German troops.

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 experimental stage. By contrast, the Empire of Japan were able to get the Yokosuka MXY7 Ohka kamikaze rocket plane type into active service, typically using the Mitsubishi G4M (Betty) bomber class to carry them within range. However, their effectiveness proved minimal in part because Allied air naval defense took advantage of the weight of the parasitical aircraft payload slowing the carrying bombers, making them vulnerable to interception before the rocket plane can separate and launch.

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 Republic 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 aerial refueling appeared as a much safer solution to extend the range of fighters.

Examples of parasite aircraft

 * Examples which have flown include:
 * A Bristol Scout was flown from a Porte Baby to become the first parasite aircraft (1916)
 * An Albatros D.III was flown from L 35 (LZ 80) to become the first parasite fighter flying from an airship (January 26, 1918)
 * A Sopwith Camel was flown from airship HMA 23 (1918)
 * A Sperry Messenger biplane was launched and recovered by non-rigid airships Tc-3 and Tc-7 (1923)
 * Several DH 53 Hummingbird light planes were launched and recovered by airship R33 (1924), followed by two Gloster Grebe fighters (1925).
 * A glider and a biplane were recovered by the USS Los Angeles. These were followed by the F9C Sparrowhawk escort fighter which flew operationally from USS Akron and Macon (1935).


 * Ohka Rocket plane on the Mitsubishi G4M.
 * The Polikarpov I-16 modified into a dive bomber carrying two 250 kg bombs (variant TsKB-29), flown from a Tupolev TB-3 as the Zveno-SPB ("composite dive bomber"), was the first parasite aircraft to see combat (1941)
 * The Messerschmitt Me 328 escort fighter was intended to fly from the Dornier Do 217/, but this was unsuccessful due to engine problems.
 * The XF-85 Goblin was an attempt to equip B-36 bombers with their own escort fighters (1948)
 * The F-84 was a more successful attempt to provide the B-36 with a parasite escort fighter in the FICON project(1952)