Cold War

FJ-2 the US Navy’s F-86 Sabre’s Brother

The FJ-2 was developed as a naval adaptation of the Air Force’s effective F-86 Sabre. Encountering operational challenges on carriers, the FJ-2 was assigned solely to Marine Corps squadrons during its front-line service. Although its carrier functionality was restricted, the FJ-2 played a role in testing the inaugural steam catapult on a U.S. Navy carrier.

The development of American jet fighters underwent significant evolution after the conclusion of World War II in 1945. Initially, U.S. jets featured straight-wing designs with fuselage-integrated engines, contrasting with the German Messerschmitt Me 262’s sweptback wings and engine nacelles mounted below the wings.

As advancements in technology emerged, American design shifted towards swept wings and the distinctive front air intake. This progress led to the iconic North American F-86 “Sabre,” a mainstay of the Korean War from 1950 to 1953 for the United States Air Force (USAF).

FJ-1 and FJ-2 together
FJ-1 and FJ-2 together

Meanwhile, the United States Navy (USN) had also invested in another North American model, the FJ-1 Fury. This carrier-based jet fighter maintained a straight-wing configuration, seated one pilot, and included a typical nose-mounted air intake with integrated fuselage ductwork.

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Primarily used in a developmental capacity, the FJ-1 Fury revealed various design flaws unsuitable for carrier operations, leading to a significant reduction in production.

From an initial order of 100, only 30 units were built. The aircraft did not engage in combat and was swiftly phased out by 1953 after its introduction in late 1947.

Background

The Korean War highlighted the limitations of straight-wing jet fighters used by Navy and Marine Corps squadrons, particularly in comparison to the Soviet-built MiG-15s.

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Observing the effectiveness of the U.S. Air Force‘s F-86 Sabre in air-to-air combat over Korea, Naval Aviation leadership approached North American Aviation, Inc., the manufacturer of the F-86, for a swept-wing design suitable for naval operations.

An F-86 Sabre
An F-86 Sabre

Interestingly, the straight-wing FJ-1 Fury, developed by North American for the Navy in the late 1940s, had previously influenced the design of the F-86. North American, seeing no need to significantly alter a successful design, introduced the FJ-2, based on the F-86 Sabre.

Capable of reaching speeds up to 676 mph—nearly 100 mph faster than the jets then flown by Naval Aviators in Korea—the FJ-2 faced operational challenges aboard ships, leading to its exclusive assignment to Marine Corps squadrons in 1954, which was too late for it to see action in the Korean War.

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By 1951, the Navy’s straight-wing fighters were outclassed by the swept-wing Soviet Mikoyan-Gurevich MiG-15, which was active in the Korean War. The Navy’s own advanced swept-wing fighters, such as the Vought F7U Cutlass and Grumman F9F Cougar, were not yet ready for deployment.

In response, the Navy’s Bureau of Aeronautics took an interim step by ordering a direct adaptation of the North American F-86E Sabres into the FJ-2. Although the F-86 was not originally designed for carrier operations, which presented some risks, it was observed that the F-86A had a lower landing speed than the Grumman F9F Panther.

The North American FJ-1 Fury is an early turbojet-powered fighter aircraft designed for aircraft carrier operations and used by the United States Navy.
The North American FJ-1 Fury is an early turbojet-powered fighter aircraft designed for aircraft carrier operations and used by the United States Navy.

During carrier qualification trials, the Navy warned Grumman to reduce the stall speed of the F9F-5 by 12 mph (19 km/h), otherwise it would be phased out of carrier operations as the FJ-2 began integrating into Navy squadrons.

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North American’s chief engineer at the time noted that the swept-wing Sabre displayed handling and stall characteristics at low speeds comparable to the best straight-winged airplanes.

Driven by urgency, the Navy initially ordered 300 FJ-2 fighters, although this number was later reduced to 200 before the prototypes had even flown.

FJ-2 First Prototype 

The first prototype of the FJ-2 to take flight was unexpectedly the third one ordered, labeled XFJ-2B. It flew for the first time on December 27, 1951, and its primary distinction from the standard F-86E-10 Sabre was its armament; it was equipped with four 20 mm Colt Mk 12 cannons instead of the six Colt-Browning M3 .50 inch machine guns typical of the Sabre.

The initial prototype of the North American Aviation XFJ-2B Fury, bearing the Bureau Number 133756, took flight from the runway at Los Angeles International Airport on December 27, 1951.

The subsequent prototypes, designated XFJ-2, were devoid of armament and had modifications for carrier use, including arrester hooks and extended nosewheel legs to improve the angle of attack during take-off and landing, along with fittings for catapult launches.

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These aircraft underwent carrier trials on the USS Midway in August 1952 and qualification trials on the USS Coral Sea from October to December 1952, but the results highlighted deficiencies: The low-speed handling was problematic, and both the arrester hook and nose gear leg proved to be insufficiently robust.

The initial production model of the FJ-2 took to the skies on November 22, 1952, featuring further adjustments for carrier duty. These included widening the main landing gear’s track by eight inches, upward-folding outer wing panels, and a modified windscreen to enhance pilot visibility during approaches.

FJ-2 Closely Resembled the F-86

The FJ-2 also introduced an all-moving tail, known as a “flying tail,” and lacked dihedral. Following issues with steam catapult launches, later models were fitted with a strengthened nosewheel strut.

Visually, the FJ-2 closely resembled the F-86, distinguishable mainly by its navy paint scheme and the visible gun muzzles of its 20 mm cannons.

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It was powered by the General Electric J47-GE-2 engine, a navalized variant of the J47-GE-27 used in the F-86F. Despite these naval modifications, which added approximately 1,100 lb (500 kg) to its weight, the FJ-2 did not fully meet the requirements for carrier operations. Consequently, it was assigned to land-based Marine Corps squadrons.

A U.S. Navy North American FJ-3 Fury from fighter squadron VF-33 Tarsiers taking off from the aircraft carrier USS Intrepid (CVA-11) in the North Atlantic during the NATO exercise "Operation Strikeback", September 1957.
A U.S. Navy North American FJ-3 Fury from fighter squadron VF-33 Tarsiers taking off from the aircraft carrier USS Intrepid (CVA-11) in the North Atlantic during the NATO exercise “Operation Strikeback”, September 1957.

Production of the FJ-2 was initially slow due to the high demand for the F-86 in the Korean conflict, with only seven units delivered by the end of 1953. The first FJ-2 reached a Marine Corps squadron, VMF-122, in January 1954.

The Navy, preferring the Grumman F9F Cougar for its superior slow-speed handling suitable for carriers, handed over all 200 units of the FJ-2 to the Marines.

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Although the Marines conducted several carrier cruises and attempted to rectify the FJ-2’s handling issues, the aircraft never fully met carrier operation standards. By 1956, the FJ-2 was withdrawn from frontline service, and by 1957, it was retired from reserve units as well.

FJ-3 Prototype

While the development of the FJ-2 was still underway, plans were already being made for a new version powered by the Wright J65, a licensed-built variant of the British Armstrong Siddeley Sapphire turbojet.

The Sapphire was expected to provide 28% more thrust than the J47 engine without a significant increase in weight. This upgraded version was designated the FJ-3, and in March 1952, an order for 389 aircraft was placed.

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To facilitate testing of the new engine, an FJ-2, with the Bureau Number 131931, was modified. The first true production model of the FJ-3 took flight on July 3, 1953. The only noticeable external change to accommodate the new engine was a deeper intake to handle the larger airflow.

An FJ-3M of VF-121 Pacemakers in 1957
An FJ-3M of VF-121 Pacemakers in 1957

Initially, the FJ-3 retained the same wing configuration as the FJ-2, but starting in 1955, it featured the “6-3” wing—a design with extended leading edges by 6 inches at the root and 3 inches at the tip, first seen on the F-86F.

This wing design improved maneuverability but resulted in a slightly higher landing speed due to the removal of leading edge slats. The FJ-3 version differed from the F-86F by incorporating camber on the underside of the leading edge to enhance low-speed handling, and it also increased fuel capacity within the new wing edges.

Despite These Problems

From the 345th aircraft onward, the wings were equipped with four stations capable of carrying external loads—up to 1,000 pounds on the inboard stations and 500 pounds on the outboard stations.

Deliveries of the FJ-3 commenced in September 1954, and the aircraft joined the fleet in May 1955. An FJ-3 notably became the first fighter to land on the newly commissioned supercarrier USS Forrestal in 1956.

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However, the J65 engine did face issues, including lubrication system failures during the stresses of launch or high-speed maneuvers and turbine blade failures.

Despite these problems, the Navy found the FJ-3 more satisfactory than the FJ-2, leading to an additional order of 149 aircraft in March 1954. With its more powerful engine, the FJ-3 outperformed most F-86 models, except the F-86H.

Ultimately, 538 FJ-3s were built, with 194 of these modified into FJ-3Ms capable of carrying AIM-9 Sidewinder missiles. Some FJ-3s were also adapted to control Regulus missiles (KDU-1) and Grumman F9F-6K Cougar target drones. In 1956, the Navy retrofitted all its FJ-3s with probe-and-drogue air refueling systems, adding a long probe under the left wing.

The Wright J65 Powerplant

Curtiss-Wright acquired the license for the Sapphire engine in 1950, intending to commence production in 1951. However, delays emerged due to Curtiss-Wright’s design modifications, notably their decision to replace the Sapphire’s machined midsection solid forged diffuser frame with a fabricated version made of welded nodular iron.

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This design change, which reduced production costs to about a fifth of the original, was later incorporated into the Sapphire design itself.

A sectioned Wright J65
A sectioned Wright J65

The Sapphire was notably efficient across all RPM ranges, operating without compressor stall, thus eliminating the need for inlet guide vanes or similar mechanisms common in other engines of the era.

However, operational issues arose when it was discovered that despite maintaining pressure at low speeds and RPM, the first stages of the compressor were stalling, leading to significant vibration and fatigue.

Wright addressed this by implementing inlet ramps that closed off the outer portions of the intake at low RPM. While Armstrong Siddeley assessed this modification for the UK versions of the Sapphire, they ultimately chose a different approach.

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By the time the Sapphire was ready for service, the Pratt & Whitney J57 had entered the market, capturing many of the J65’s potential clients.

Despite this, the J65 powered several key aircraft including the Martin B-57 Canberra, its initial intended platform, as well as versions of the North American FJ Fury, Douglas A-4 Skyhawk, Republic F-84F Thunderstreak, and the two Lockheed XF-104 Starfighter prototypes.

Notably, Grumman, experiencing underperforming afterburning thrust with the engine in the F11F Tiger, opted for the General Electric J79 in the Grumman F11F-1F Super Tiger.

Armstrong Siddeley Sapphire Powerplant

The Armstrong Siddeley Sapphire, a British turbojet engine developed by Armstrong Siddeley in the 1950s, represented the culmination of advancements that began with the Metrovick F.2 in 1940. This engine featured a sophisticated axial flow design with an annular combustion chamber and achieved a thrust of over 11,000 lbf (49 kN).

Armstrong Siddeley Sapphire (J65) turbojet engine
Armstrong Siddeley Sapphire (J65) turbojet engine

It was utilized in early models of the Hawker Hunter and Handley Page Victor, as well as every Gloster Javelin. Additionally, production of the Sapphire commenced under license in the United States by Wright Aeronautical as the J65, which powered several U.S. aircraft designs. Its main competitor during this era was the Rolls-Royce Avon.

The evolution of the Sapphire’s design began in 1943 at Metropolitan-Vickers (Metrovick) as a derivative of the F.2 project.

Upon achieving flight quality with the F.2, which produced approximately 1,600 lbf (7,100 N) of thrust, Metrovick expanded its focus to include larger engines, notably the Beryl and the significantly larger F.9 Sapphire. The naming convention shifted to gemstones for future engines.

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The Beryl, achieving 4,000 lbf (18 kN) of thrust, was intended for the ultimately cancelled Saunders-Roe SR.A/1. The F.9 was designated by the Ministry of Supply as the MVSa.1.

In 1948, Metrovick exited the jet engine market, and Armstrong Siddeley, which had its own turbine project, the ASX, acquired the MVSa.1, subsequently renamed ASSa.1. After further development, it was introduced as the ASSa.2.

By December 1949, the ASSa.2 passed its acceptance test with a thrust of 7,380 lbf (32,800 N), surpassing the thrust of its rival, the Avon RA.3, which at the time was 6,500 lbf (29,000 N). The Sapphire gained interest from multiple companies and was considered for use in most British aircraft designs from the late 1940s to the early 1950s.

The ASSa.5 version, generating 7,500 lbf (33,000 N) of thrust, was exclusively used on the English Electric P.1A, the prototype of the Lightning.

A simple fixed-nozzle reheat system was integrated to enhance the aircraft’s performance, extending its stability and control from about Mach 1.1 to beyond Mach 1.5. Subsequent versions of the Lightning were equipped with the Avon engine.