History
Background
The initial F7U Cutlass was developed in response to a competition organized by the US Navy for a new carrier-capable day fighter, which was announced on June 1, 1945. The requirement for the new fighter included the ability to fly at speeds of up to 600 miles per hour and altitudes of up to 40,000 feet.
Chance Vought proposed a radical aircraft design with an unconventional tailless configuration. The aircraft featured broad-chord, low-aspect-ratio, swept wings, with a wing-mounted tail fin on both sides of a short fuselage, assembling a semi-tailless twin-engine jet. In addition, the cockpit was located as far forward as possible for pilot visibility. This design was designated company type number V-346A, which later became the official name of F7U, and it was the last design overseen by Vought’s Rex Beisel, who designed the legendary F4U Corsair and other aircraft since 1922. Sources indicated this design was inspired by and/or influenced by Messerschmitt and Arado aerodynamic engineers, although Vought officially denied this association.
Bids were to be submitted by April of 1946. By the deadline, twelve different designs were submitted by six companies: Vought, McDonnell, North American, Curtiss-Wright, Martin, and Douglas. The Vought V-346A design was chosen as the winner on June 25, 1946, and designated XF7U-1.
The Navy ordered three XF7U-1 prototypes in that month of 1946. They were powered by a pair of infamous Westinghouse J34 turbojet engines. In September 1948, the prototype rolled out and performed its maiden flight in Maryland. Several issues were immediately encountered during this initial flight, but it had attained a maximum speed of 625 mph. The Navy named the aircraft Cutlass after the initial flight and awarded a contract for the production of 14 F7U-1s with the same powerplant. Over the two years of XF7U-1 flight testing, all three prototypes were lost in accidents.
None of the 14 F7U-1s built between 1950 and 1952 were accepted for service, noting the dissatisfaction with the underpowered J34 engines and poor visibility. The Navy terminated the F7U-1 production and wanted to modify and improve the F7U aircraft, so it awarded Vought a contract to produce 88 F7U-2 Cutlasses on September 23, 1949. It was later canceled by the Navy because of engine development issues. After serious consideration of canceling the entire Cutlass production in 1951, the Navy decided to fund the F7U-3 program. The lack of alternatives for the replacement and introduction of more powerful steam catapults for the aircraft carriers prompted the Navy to continue the F7U-3 program considerably.
F7U-3 Development
The F7U-3 was a new Cutlass design to address the shortcomings of the F7U-1. As a result, the aircraft incorporated many changes that improved its performance, visibility, armament, range, airframe, and maintenance. It had a roll rate of 570 degrees a second, three times that of most production jets. Its fully steerable nose gear was extremely tall and placed the pilot 14 feet in the air. Although these changes were positive, the cockpit and radar nose design did not provide adequate carrier landing visibility.
The first 16 F7U-3s were powered by non-afterburning Allison J-35 engines rated at 5,600 pounds maximum thrust. As built, these 16 F7U-3s had a single-wheel nose gear similar to the F7U-1’s. These were later retrofitted to the dual nose wheels. They were armed with four 20-mm cannons, which were mounted in the fairing above the engine duct and fired through ports in the duct lip. The stainless steel vents were installed to prevent the engine flameout caused by the exhaust gases of gunfires.
The following Bureau Numbers of the 16 early F7U-3s are 128451 - 128466.
The remaining F7U-3s after the 16th aircraft were powered by Westinghouse J46-WE-8B afterburning turbojets, and they had dual nose wheels instead of single wheels. The cockpit was raised to provide slightly better visibility, and the radar nose was slanted downward for more visibility at the bottom. These aircraft became the definitive production standard. A total of 288 aircraft were equipped with 13 US Navy squadrons. The F7U-3 was the last major Cutlass variant, and the further development of the Cutlass ended shortly after flight testing of the more capable Vought F8U Crusader commenced.
One way to visually differentiate between early and standard F7U-3 is the shape of the radar nose. Early -3 had a bulb-shaped radar nose, while the standard -3 had the radar nose slanted downward.
F7U-3 in Operational Service
The first fleet squadron to receive the early F7U-3s was Fighter Squadron 81 (VF-81) in April 1954. The pilots across squadrons disliked the F7U-3’s performance due to a lack of sufficient engine thrust. The carrier’s landing and take-off performance was still severely poor because of it. In addition, the J35 engines were known to flame out in rain during flight, which was a serious blunder of the design.
When the Westinghouse J-46-WE-8 turbojet engines with afterburning capability became available, the early F7U-3s in service were replaced with new and standard F7U-3s. Their air intakes had to be enlarged to provide more air for the engines. Although the new engines promised to improve the flight performance, the Cutlass aircraft could not generate more than 6,100 pounds of thrust, falling short of the expected 10,000 pounds in the afterburner. Thus, it would be the most complicated in-service aircraft for the US Navy pilots to maintain and fly.
Ultimately, between June 1954 and December 1956, 13 fleet squadrons received Cutlasses. At 55,000 hours of cumulative flight time, there were 78 accidents related to the Cutlass aircraft and one-quarter of airframes lost. These accidents were attributed to hydraulic failures, landing gear failures, and underpowered engines, which had fatally claimed four test pilots and 21 other US Navy pilots. In addition, the pilots suffered spinal injuries after nose gear failure during a high-stress landing. Most squadrons that equipped the Cutlass aircraft took every Cutlass from the aircraft carrier and “beached,” or grounded them ashore because of these defects.
Plagued by accidents and deficiencies, the Cutlass aircraft was retired on March 2, 1959, after only serving for around ten years. The accidents and losses marked the highest accident rate of all Navy swept-wing fighters in the era, which had forever tarnished Cutlass’ reputation.
