The Convair XFY-1 Pogo was an experimental vertical takeoff aircraft of the 1950s. It was a result of a proposal issued by the Navy in 1948 for an aircraft capable of vertical takeoff and landing (VTOL) aboard platforms mounted on the afterdecks of conventional ships. In 1950, this requirement was revised to call for a research aircraft capable of evolving into a VTOL ship-based convoy escort fighter. In March of 1951, three prototypes were ordered from Convair under the designation XFY-1. A similar aircraft was also ordered from Lockheed under the designation XFV-1.

The XFY-1 sat on its tail for landings and takeoffs. It had a large delta wing with two pods at the extreme and two large vertical fins above and below the fuselage. The aircraft rested on a set of small castoring wheels at the tips of the wing and fin. At takeoff, the engines ran up to full power and the aircraft ascended vertically, then when it reached a safe altitude it gradually nosed over into conventional horizontal flight. At landing, the aircraft approached the landing pad while pitched up into a nose-high position and then descended to the ground under gradually reduced power. If an emergency were to occur, the ventral fin could be jettisoned so that the aircraft could make a crash-landing in conventional, wing-supported mode.

The XFY-1 was powered by an Allison YT40-A-6 turboprop (which consisted of two T38 turboprops coupled together) driving a pair of Curtiss-Wright 16-foot three-bladed counter-rotating propellers in the nose. The engine offered a power of 5500 shp. The air intakes for the engines were located in the extended roots of the delta wing, and the exhaust was in the extreme tail.

The single pilot sat underneath a cockpit canopy which slid toward the rear. The ejector seat was mounted on gimbals and tilted 45 degrees when the aircraft was in the vertical position. Entry to or exit from the cockpit required a special ladder, and was by all accounts rather awkward. During takeoffs and landings, the canopy was slid to the rear to give the pilot a better view.

The proposed armament (never actually fitted) was four 20-mm cannon fitted in the two wingtip pods. Alternatively, 48 2 3/4-inch folding-fin rockets could be fitted.

This is a diagram of a jet turbine and not the actual Allison that was used in the Pogo

Allison T-40A Engine.. The T40 was an attempt to produce a high power turboprop engine by combining two T38 engines side-by-side with a joint gearbox to combine power and reduce shaft speed to that necessary for a propeller. This combination was used with a contra-rotating propellers system. I took this earlier this year at the Rolls-Royce Allison Division Museum in Indianapolis, IN. Feel free to use it for your documentation and keep up the good work. Tom Fey In the late 1940s and early 1950s this engine was favored by the US Navy and was used in several aircraft, the XA2D, XA2J, P5Y, R3Y, and the several VTOL developments including the Hiller X-18, the XFV-1, and XFY-1. The USAF's XF-84H Thunderscreech also tried this engine with a single 3-bladed propeller. As the individual power plants were clutched into the gearbox, it was intended in most instances that the aircraft could cruise on one half the engine and only engage the second power-section when there was need. In practice the system did not work so well. Failure to recognize that one of the T38s had failed, and its compressor was devouring power produced by the other section, led to the loss of the first prototype XA2D-1 and its pilot Lt. Cmdr. Hugh Wood on 14 December 1950. The major problems of the T40 were its fragile gearbox, and the prop-control system which used 25 vacuum tubes, and was far from reliable. T40-engines on the XP5Y-1 prototype in 1950 The T40 never produced the 5,500 horsepower it was supposed to deliver, and was plagued by gearbox failures, runaway props and prop control failures.

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Before attempting the first flights, the prototype ..XFY-1 was attached to a complex tether system inside a huge hangar at NAS Moffett Field, California that allowed the aircraft to move up or down freely, but severely limited the lateral displacement. During the summer of 1954, test pilot James F. "Skeet's" Coleman made several tethered flights in this system. The first un-tethered vertical flight was made on August 1, 1954. During the next two days, several vertical hovering flights were made during which the aircraft reached altitudes as high as 150 feet. The aircraft was then returned to San Diego for further tests at NAAS Brown Field. The first successful transition to horizontal flight took place on November 2, 1954, during which the XFY-1 flew horizontally for 20 minutes before coming back and landing inside a 50-foot square. This was the first successful VTOL flight in history in an aircraft that was not a helicopter or an autogiro.  For this feat, Coleman was awarded the Harmon Trophy.

Unfortunately, the XFY-1 was difficult to land because of a poor view from the cockpit of the landing area and the unusual pilot posture. The landing operation would probably have been difficult if not impossible for a pilot of ordinary ability to perform on a small deck aboard ship, especially in rough seas where the deck was pitching back and forth. In addition, the T40 turboprop was mechanically complex and was thoroughly unreliable and subject to frequent breakdowns.  The T40 was, in fact, the cause of the failure of several combat aircraft projects of the era.   In addition, by this time the performance of the XFY-1 was quite a bit less than that of conventional jet aircraft, and would probably not have been able to hold its own in air-to-air combat. For this reason, the XFY-1 program was cancelled after only 40 hours of flight testing.