The F4D-1 was the initial production version of the Skyray. It had been ordered by the Navy in March of 1953, and was to have been powered by the Pratt & Whitney J57-P-2 axial-flow turbojet offering 9700 lb.s.t. dry and 14,800 lb.s.t. with afterburning. The modifications needed to adapt the Skyray to the Pratt & Whitney J57 turbojet were considerable, and approximately 80 percent of the airframe had to be redesigned.
The first production F4D-1 (BuNo 130740) took off on its maiden flight on June 5, 1954. According to some reports, it exceeded the speed of sound in level flight during its first flight. But this is doubtless incorrect. It's likely that the first production F4D did break the sound barrier on its first flight, but it had to be in a dive. It's possible that the pilot then leveled out and was briefly supersonic in level flight but rapidly decelerating back to a subsonic speed
During flight test, frequent engine stalls were encountered at high speeds above 40,000 feet, and it was found necessary to modify the geometry of the air intakes and to add an airflow baffle plate ahead of each air intake in order to alleviate this problem. Changes also had to be made to the fairing around the afterburner exhaust in order to make the airflow smoother, eliminating a high-speed turbulence problem that had been encountered during early flight testing of the F4D-1 with the J57 engine. But the plane was still unable to break the sound barrier in level flight, only in a dive.
It was not until early 1956 that the first production F4D-1s could be delivered to Navy service units. The first Navy unit to receive Skyrays was Composite Squadron 3 (VC-3) based at NAS Moffett in California, which got its first planes on April 16, 1956. This outfit performed the initial service evaluation of the type. The first truly operational unit was VF-74 at NAS Oceana in Virginia, which came on line in mid 1956. In early 1957, Skyrays were issued to the Marine Corps, the first unit to receive the type being VMF-115 based at MCAS Cherry Point in North Carolina.
A total of 419 production F4D-1s were built, the last example being delivered on December 22, 1958. At least 230 others were cancelled.
On May 22 and 23, 1958, Major Edward N. LeFaivre of the Marine Corps set five time-to-height records in F4D-1 BuNo 130745. These were 3000 meters (9842.5 feet) in 44.39 seconds, 6000 meters (19,685 feet) in 1 min 6.13 seconds, 9000 meters (29,527.5 feet) in 1 minute 29.81 seconds, 12,000 meters (39,370 feet) in 1 minute 51.23 seconds, and 15,000 meters (49,212.5 feet) in 2 minutes 36.05 seconds.
Late production F4D-1s were powered by the J57-P-8,P-8A, or P-8B turbojet which offered 10,200 lb.s.t. dry and 16,000 lb.s.t. with afterburning. The F4D-1 was equipped with an APQ-50A radar mounted in the nose. This radar was interfaced with an Aero 13F fire control system. Later production versions were equipped with seven hardpoints for external loads, three under each wing and one on the ventral fuselage centerline. Underwing loads could consist of six pods, each containing seven 2.75-inch unguided rockets, four pods containing 19 2.75-inch rockets each, two 2000-pound bombs, or two Sidewinder air-to-air missiles.
VC-3 was later redesignated VFAW-3, and was attached for a time to the Air Defense Command. While with the ADC, VFAW-3 was based at NAS North Island, San Diego, California. These aircraft participated in the aerial defense of the United States, and carried an electronics package on the fuselage centerline pylon, a pair of 300-gallon underwing drop tanks, a pack of 12 2.75-inch unguided rockets on each of the outer underwing pylons, and a Sidewinder air-to-missile on each of the wing root pylons.
The F4D-1 was used by a total of eleven Navy squadrons and by six Marine Corps fighter squadrons, as well as by three reserve squadrons and by several specialized units. The Navy squadrons using the Skyray were VFAW-3, VF-13, VF-23, VF-51, VF-74, VF-101, VF-102, VF-141, VF-162, VF-213, VF-881, VF-882. The Marine Corps units using the Skyray were VMF-113, VMF-114, VMF-115, VMF-215, VMF-314, VMF-513, VMF-531, VMF-542. Both carrier- and land-based units were equipped with the Skyray.
In September of 1962, the F4D-1 was redesignated F-6A under the new tri-service designation system. By this time, the Skyray was in service with only four front-line squadrons (VFAW-3, VMF-114, VMF(AW)-542, and VMF-531) and with three reserve units (VF-881, VF-882, and VMF-215). VMF(AW)-542 was the last active duty Skyray squadron, rotating back to the USA in November 1963 from Atsugi, Japan.
The service life of the Skyray with the Navy and USMC was relatively brief, since the aircraft was specialized to the high-altitude interception role and lacked the multi-mission capability that was becoming increasingly important. The Skyray had a good climb rate, a high ceiling, a relatively high speed, and a good radar, all features which made it a good interceptor. But a 1957 Navy evaluation report concluded that the F4D-1 was only marginally effective as an all-weather fighter. Major deficiences were a modwest maximum speed capability, poor transonic flying qualities, and armament control system limitations. It did not have a level flight supersonic capabilityh and supersonic speeds could only be maintained in a dive. In addition, it had a reputation of being a difficult plane to fly. The last Skyray left service on February 29, 1964. The Skyray never saw any combat, although it was deployed to Taiwan in 1958 and to Guantanamo in 1962 in response to crises.
In 1956, F4D-1 BuNo 134759 was transferred to NACA at Ames for various research and development tasks. It was retired in 1959.
BuAer serials of Douglas F4D-1 Skyray:
130740/130750 Douglas F4D-1 Skyray 134744/134973 Douglas F4D-1 Skyray 136163/136392 Douglas F4D-1 Skyray - contract cancelled 139030/139207 Douglas F4D-1 Skyray
Specification of Douglas F4D-1 Skyray:
Engine: One Pratt & Whitney J57-P-8, 8A, or 8B turbojet, 10,200 lb.s.t. dry and 16,000 lb.s.t. with afterburning. Performance: Maximum speed 722 mph at sea level, 695 mph at 36,000 feet. Cruising speed 520 mph. Initial climb rate 18,300 feet per minute. Service ceiling 55,000 feet. Combat ceiling 51,000 feet. Landing speed 134 mph. Normal range 700 miles, maximum range 1200 miles. Weights: 16,024 pounds empty, 22,648 pounds combat, 25,000 pounds gross, 27,116 pounds maximum. Dimensions: wingspan 33 feet 6 inches, length 45 feet 3 inches, height 13 feet 0 inches, wing area 557 square feet. Internal fuel capacity was 640 US gallons. Two 150-US gallon or 300-US gallon drop tanks could be carried underwing, bringing total maximum fuel capacity to 1240 US gallons. Armament: Armed with four 20-mm cannon in the wings. External stores of up to 4000 pounds in weight could be carried on seven wing and fuselage hardpoints (Four underneath the wings, two underneath the wing roots, and one on the fuselage centerline). Underwing loads could consist of six pods each containing seven 2.75-inch unguided rockets, four pods containing 19 2.75-inch rockets each, two 2000-pound bombs, or two Sidewinder air-to-air missiles.
Sources:
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The Aircraft of the World, William Green and Gerald Pollinger,
Doubleday, 1965.
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The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.
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United States Navy Aircraft Since 1911, Gordon Swanborough and
Peter M. Bowers, Smithsonian, 1989.
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Flying the Frontiers--NACA and NASA Experimental Aircraft, Arthur
Pearcy, Naval Institute Press, 1993.
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McDonnell Douglas Aircraft Since 1920: Volume 1, Rene J. Francillon,
Naval Institute Press, 1988.
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Ray Wagner, American Combat Planes, Third Enlarged Edition,
Doubleday, 1982.
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Killer Rays: The Fast-Climbing, Bat-Winged Douglas F4D
Skyray and F5D Skylancer, Peter Hackett, Wings, Dec 1997,
Vol 27 No. 6.
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E-mail from Jim Keith on service of Skyray with VMF(AW)-542, the last active duty unit.
- E-mail from Tommy Thomason on inability of F4D-1 to achieve level-flight supersonic performance.
