A high performance fighter which could take off and land vertically, like a helicopter! No more need to depend upon elaborate and vulnerable airfield facilities in time of war. Every paved highway, even every level patch of farmland suddenly capable of launching a cloud of fighters to deal with an invading army. And more! Fighter protection at sea which doesn't require huge aircraft carriers- -every destroyer, even every transport and oiler, capable of carrying one or two fighters of its own! Such an aircraft would present any attacker with enormous difficulties and therefore would help mightily to preserve the world's peace.
In the late 1940s and early 1950s the US Navy sought to develop an aircraft that could take off and land vertically, eliminating the need for large aircraft carriers, and providing instantly available of air support for landing troops. It was thought that the best way to provide this was with a tailsitting aircraft, and the newly developed turboprop was to be used since supersonic speed was not necessary.
The Allison YT-40, consisting of two smaller T-32 engines mounted in tandem and connected to a single, massive gearbox, delivered its combined 5,280 horsepower to a pair of 16 ft counter-rotating propellers. Although the powerful new engine was still under development, and in fact required further modifications to equip it for sustained vertical flight, it offered enough promise for the Navy to issue a pair of contracts to Convair and to Lockheed to develop competing fighter prototypes.
Two companies, Lockheed and Convair were chosen to provide prototypes. Both airframes used an experimental turboprop engine and both were designed to be tail sitters. On 31 March 1951 a Navy program for development of a propeller-driven vertical takeoff fighter was initiated with issuance of a contract to Convair for the XFY-1. A somewhat similar aircraft, the XFO-1 (later redesignated XFV-1), was ordered from Lockheed three weeks later as an alternate solution to the design problems. The Convair aircraft was unofficially--and probably inevitably--dubbed the Pogostick. Lockheed's own VTOL never received an official nickname but, oddly enough, both aircraft soon came to be known interchangeably as Pogo, by public and insiders alike.
The Convair XFY-1 used a delta planform and + shaped tail, and featured turboprop- powered contrarotating propellers to supply the vertical thrust. As development continued, it became obvious that both the aircraft and pilot would be operating at the very limits of their capabilities. Lockheed's problem was compounded by the fact that only one YT-40 engine suitably configured for vertical flight was immediately available. As the first contract signer, Convair received the engine and was able to proceed directly to vertical flight testing.
On 02 November 1954 the XFY-1 delta wing experimental fighter, piloted by J. F. Coleman, made a successful flight at NAS Moffett Field, consisting of vertical takeoff, transition to horizontal and return to vertical position for landing. The first free vertical takeoff had been made 1 August. For his contribution to the art of flying, in testing the XFY-1, Coleman was later awarded the Harmon International Trophy for 1955.
The XFY-1 was able to successfully take off and land vertically. The project was cancelled at the completion of this flight test program in 1955 from a combination of handling problems and the realisation that the design could not match the performance of contemporary fighter aircraft. The main problems with these VTOL airplanes were the tricky piloting maneuvering required in the take-off and landing and the need to tilt the entire aircraft over into conventional flight.
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