F3H McDonnell Demon

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McDonnell Demon
As Navy fighters increased in weight and complexity, they became more dependent on their power plants for success. The failure of the Westinghouse J40 selected for the McDonnell XF3H-1 Demon almost doomed that single-seat fighter with swept wings and tail.

Two prototypes ordered September 30, 1949, and a program for 150 Demon interceptors was planned as early as March 1951. Production aircraft were to be all-weather fighters, known as the F3H-1N, with larger radar and more fuel. While gross weight would increase from 20,000 to 29,000 pounds, a more powerful J40-WE-24 turbojet was expected to compensate for the increase.

McDonnell F3H-lN

After the XF3H-1 prototype flew August 7, 1951, with a 6,400-pound thrust XJ40-WE-6, the same engine also powered the second prototype until a J40-WE-8 with after­burner became available in January 1953. A hopeful Navy had increased the production program to 528 aircraft with more to be built by Temco, but the J40 continued to suffer difficulties. In April 1952, McDonnell recommended using the Allison J71-A-2 instead, and in November the Navy decided that turbojet would be used, beginning with the 61st Demon.

McDonnell F3H-2N

By September 1953, it became apparent that the earlier F3H-lN would have to be content with the 10,900-pound thrust available from the J40-WE-22. The first F3H-lN was flown on January 24, 1953, with provisions for APG-30 radar and four 20-mm guns. The handicap of the additional weight soon became apparent, and November the contract was reduced, and in July 1955, after the fourth pilot was killed in a series of 11 accidents that had destroyed six F3H-lNs, the type was permanently grounded.

The engine’s power was judged insufficient for the airframe’s weight. All survivors of the first 60 Demons could be used only for mechanics’ ground training, except for two converted by installation of Allison J-71s to test the F3H-2 standard. Failure of the F3H-lN had cost the Navy some $200 million, mostly expended on the unsuccessful J-40 engine. McDonnell F3H-2M (with Sparrow I)

The first converted F3H-2N, flown on January 11, 1955, had a 14,400-pound thrust Allison J71-A-2 and the wing area increased by a wider chord at the roots. An APG-51 radar was fitted in front of the cockpit between the large air intakes on each side, and four 20-mm guns with 600 rounds were ­below the cockpit. The wings could hold two 282-gallon drop tanks, had leading edge slats, and folded upwards.

First flown April 29, 1955, 142 F3H-2Ns entered squadron service in March 1956 with VF-14, which sailed on the giant Forrestal’s first overseas deployment in 1957. The first of 80 F3H-2Ms was flown on August 23, 1955, and VX-4 at Point Mugu began testing the weapons system replacing guns with four Sperry Sparrow I (AAM-N-2) beam-riding missiles aimed by APG-51B radar. McDonnell F3H-2 (F-3B after 1962)

Demon development matured when delivery began in July 1957 of the 239 definitive F3H-2 configurations that introduced four Raytheon Sparrow III radar-homing missiles (AAM-N-6) for distant targets and used the four guns for close work. Two heat-seeking Sidewinders (AAM-N-7) could replace the Sparrows if the climb advantages of light-weight condition were desired. Six underwing stations could carry bomb or rocket stores, and inflight refueling equipment allowed extended range.

McDonnell delivered the last of 519 Demons on November 17, 1959, and they served 22 fleet fighter squad­rons with two training squadrons, as well as the evaluation squadrons on each coast. The F3H-2, F3H-2M, and F3H-2N were redesignated F-3B, MF-3B, and F-3C in 1962, and the last F-3B was retired from VF-161 in August 1964.