Convair XFY Pogo

https://en.wikipedia.org/wiki/Convair_XFY_Pogo

The Convair XFY Pogo tail-sitter was an experiment in vertical takeoff and
landing. The Pogo had delta wings and three-bladed contra-rotating propellers
powered by a 5,500 hp (4,100 kW) Allison YT40-A-6 turboprop engine. It was
intended to be a high-performance fighter aircraft capable of operating from
small warships. Landing the XFY-1 was difficult, as the pilot had to look over
his shoulder while carefully working the throttle to land.

After World War II, the Cold War prompted the United States Army and Navy to
study VTOL operations. It was envisaged to protect task forces, convoys or any
fleet, even without aircraft carriers, by placing VTOLs on any ship. These
fighters would be housed within a conical protective housing, saving limited
deck space available aboard ships. They would provide first line of airborne
defense and reconnaissance capability, before more aircraft could be scrambled
to help.

In May 1951, Lockheed and Convair were awarded contracts in the attempt to
design, construct, and test two experimental VTOL fighters that would be
suitable for use by the Armed forces. Although contract stipulations stated that
each manufacturer have two fighters, each was only able to construct one, with
Lockheed producing the XFV, and Convair producing the XFY, nicknamed the "Pogo".
The first XFY-1 prototype was used for engine testing and the third for static
testing and only the second prototype serial number 138649 was flown.

The XFY-1 was designed for the Allison YT40-A-14 turboprop expected to deliver
7,100 shp (5,295 kW), the production aircraft were intended to use the even more
powerful Allison T54 which was never built. It had delta wings, swept at 52
degrees, and a fin with a span of 21 ft 8 in (6.5 m). The pilot's seat was
mounted on gimbals allowing for movement from 45 degrees in vertical flight to
90 degrees in horizontal flight. The Curtiss-Wright Turbo-electric co-axial
contra-rotating three-bladed propellers were 16 feet (4.88 m) in diameter.


Role
Experimental VTOL fighter aircraft

Manufacturer
Convair

First flight
19 April 1954 (tethered)
1 August 1954 (free flight)

Primary user
United States Navy

Produced
1954

Number built
3 (only 1 flown)

On 19 April 1954, a Convair engineering test pilot and Marine reservist,
Lieutenant Colonel James F. "Skeets" Coleman, made the first tethered flight in
the Pogo. The XFY-1 was like no other propeller driven aircraft before it. No
previous aircraft with a similar weight, engine power, or size had ever
attempted to take off and land vertically. For the safety of both the craft and
its pilot, the propeller hub cover was removed and replaced by safety tether
lines for the first flight, in case Coleman would lose control of the craft and
would need to be tethered to prevent the craft falling to the ground. On the
other end of the tether was another engineer, Bob McGreary. If Coleman ever lost
control, McGreary controlled the winch which could be turned to raise the
tethers to prevent the craft from plummeting to the ground. For further safety
precautions, four security cables were fastened to each wing in case control was
lost in any axis. The tests were conducted inside of a naval airship hangar at
Moffett Field in Mountain View, California

Throughout the next few weeks, Coleman logged almost 60 hours in test flights in
the Pogo, and by August, the test was moved to outdoor conditions. On 1 August
1954, Coleman logged two outdoor test flights, the second flying 150 ft (50 m)
into the air, and shortly after he flew 70 takeoff–landing drills at the Naval
Auxiliary Air Station in Brown Field, California. The first conversion to
horizontal flight took place on 5 November 1954.

Upon later flights with longer durations, flaws in the design were found. Due to
the Pogo's lightweight design, and the lack of spoilers and air brakes, the
aircraft lacked the ability to slow down and stop efficiently after moving at
high speeds. Landing was also a problem, as the pilot had to look back behind
himself during a landing to properly stabilize the craft.

It became evident that even if technical problems could be overcome, such VTOL
aircraft would be flown only by the most experienced pilots. Thus, it was not
feasible to place VTOL fighters—as previously hoped for—on every ship. Also,
whereas jet-engined fighters had top speeds that approached Mach 2, the
turboprop VTOL fighter was at a disadvantage with a top speed around Mach 1. Due
to these problems, the XFY Project was put on hiatus.

Although a test flight was made on 19 May 1955, it again ended with failure, and
on 1 August 1955 the project was formally concluded. The last flight of the
XFY-1 Pogo took place in November 1956.

Specifications (XFY-1)

General characteristics
Crew: 1
Length: 32 ft 3 in (9.8 m)
Wingspan: 27 ft 8 in (8.4 m)
Height: ft in (m)
Wing area: 355 ft² (33 m²)
Empty weight: 11,139 lb (5,060 kg)
Useful load: 13,250 lb (6,016 kg)
Loaded weight: 14,250 lb (6,470 kg)
Max. takeoff weight: 16,250 lb (7,370 kg)
Powerplant: 1 × Allison YT40-A-6 turboprop engine, 5,100 shp (3,803 kW)
Propellers: 3-bladed contra-rotating propellers

Performance
Maximum speed: 474 mph (412 kn, 763 km/h) at 15,000 ft (4,600 m)
Range: ˜500 mi (308 nmi, 805 km)
Service ceiling: 37,500 feet (11,440 m)
Rate of climb: 9,980 ft/min to 20,000 ft (3,045 m/min)
Max. wing loading: 38.1 lb/ft² (186 kg/m²)
Minimum power/mass: 0.34 hp/lb (560 W/kg)

Armament

Guns: 4 × 20mm (0.79 in) cannon, or
Rockets: 48 × 2.75 in (70 mm) Mk 4 Folding-Fin Aerial Rockets




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