The F9F family was an extensive series of American Navy jet aircraft made up of many variants. These aircraft were well praised during their service, in total flying 78,000 sorties. They also were the first jet fighter aircraft to see air-to-air combat with the US Navy and played a big part in the war over Korea. After their service they would even be seen flying with the Blue Angels.
Development:
In the late 1940s, the United States Navy was on the hunt for a new fighter jet that could keep up with the rapidly advancing technology of the time. The answer came in the form of the F9F Panther, a sleek and powerful aircraft that would go on to become one of the most iconic jets of the Korean War era.
On 11 April 1946, the Navy’s Bureau of Aeronautics (BuAer) issued a development contract to Grumman to produce a pair of G-75 prototypes, which were given the designation XF9F-1, however these prototypes was deemed lacking in potential by Grumman and were swapped out by a different aircraft, the G-79 which is what is now known as the F9F Panther.
Due to the lack of reliable engines, these aircraft would be fitted with Rolls-Royce Nene turbojet. This engine was used for basic testing and was able to produce 5000lbs of thrust. Pratt & Whitney were eventually able to license produce these engine under the designated J42.
On 21 November 1947, the prototype Panther flew its maiden flight, piloted by test pilot Corky Meyer in abysmal weather. It was followed by the second prototype only five days later. During testing Corky Meyer put the aircraft into some stalls, saying it performed like the J3 Cub, a famous light-weight trainer aircraft. Initial issues with directional and longitudinal stability were encountered, but were quickly fixed. Unexpectedly, during some arresting gear tests the detachable rear section of the aircraft unintentionally came off, this was later strengthened by Grumman to prevent it repeating in the future.
Variants:
The F9F had many variants, some more popular than others. These are the more notable and interesting ones:
F9F-2/F9F-3:
The first variant which entered production with a total of 477 F9F-2 and 69 F9F-3s, this variant was well liked by its crew. The F9F-3 variant was fitted with the Allison J33 turbojet but this engine was deemed too unreliable and all F9F-3s were converted to F9F-2s. The F9F-2 also had another variant, the F9F-2B. This aircraft had underwing racks for rockets and bombs, but this variant name was dropped after all F9F-2s were brought up to this standard.
F9F-5:
The F9F-5 was the most produced variant and it was an upgrade over the previous models featuring an improved Pratt and Whitney J48 engine and a longer fuselage with greater fuel load. The F9F-5 used a system involving pressurized air from the engine to blow over its slot flaps. This increased the effective airflow, mimicking higher airspeed and reducing stalling speed. This innovation improved takeoff and landing performance by lowering stalling speed by 9 knots (17 km/h) during takeoff and 7 knots (13 km/h) during landing. The F9F-5P was a photo reconnaissance version, characterized by its longer nose (Image 1). 655 F9F-5 and 28 F9F-5Ps were built.
F9F-3 (BuNo 122562):
In the summer of 1950, a F9F-3 (BuNo 122562) was fitted with an experimental electro-hydraulically driven Emerson Aero X17A roll-traverse turret housing four 0.50 caliber heavy machine guns. The guns could be directed at any angle from directly forward to 240 degrees back, and the gun mount could be rolled a full 360 degrees in either direction. The turret could roll at a rate of 100 degrees per second, and the guns could be traversed at up to 200 degrees per second. This was done to better engage bombers
Although the tests with the turret went fairly well, the volume required for the fire control system avionics, not to mention its weight and that of the turret, made it impractical for a single-seat fighter and the program was cancelled after some aerodynamic flight testing had been accomplished. Missiles, and to a lesser extent rockets, proved to be the solution for bomber hunting.
F9F-8 Cougar:
The F9F-8, also known as the F-9 Cougar, was a successor to the straight-winged F9F panther. Due to the swept-winged Soviet jet known as the MiG-15, Grumman started the project in the early 1950s with an earlier variant known as the XF9F-6 performing its maiden flight on 20 September 1951.
The F9F-8 project kicked off in April 1953 with three main goals: reduce stall speed, enhance control at high angles of attack, and extend its range. To achieve this, the fuselage was stretched by 8 inches (20cm) and the wings were reworked with a larger area and a dogtooth design. These adjustments improved low-speed performance and handling during high angles of attack while also creating space for larger fuel tanks. This variant also included the possibility of mounting a refueling probe.
It had an increased top speed due to its more powerful Pratt and Whitney J48 engine and a reduced minimum catapult speed. The aircraft could also break the sound barrier in a steep dive. A redesign mounted all four ammunition boxes above the guns, unlike earlier F9Fs. Visibility which was already impressive, got even better in this version.
Between April 1954 and March 1957, 601 units were delivered. Later models were equipped to carry four AIM-9 Sidewinder missiles under the wings, 2 on each side. This was the first Navy aircraft to feature them. Earlier models were later modified for Sidewinders, and some were outfitted for nuclear bomb deployment.
Exports:
The only foreign buyer of the Panther was Argentina, which purchased 28 F9F-2 aircraft during 1957, the first 10 arrived in 1958. Only 24 aircraft were put in service, as the remainder were used as spares. The first flight of an Argentine Panther was in December 1958.
Argentina’s Navy was also the only buyer of the F9F-8, specifically the trainer variant (F9F-8T) with it being the first Argentinian aircraft to break the speed of sound.
Usage:
All variants of the Cougar saw very little use with either Argentina or the US as they came too late to participate in the Korean war. However the F9F-8 would be seen flying with the Blue Angels.
But on the other hand, the earlier F9F Panther saw much more use in the Korean War, flying more than 78,000 sorties mainly in a ground attack role due to how rugged it was, being able to soak up enemy fire and still land. For example on 3 July 1950, Leonard H. Plog, flying an F9F-3 achieved the first US Navy air victory of the war by shooting down a Yak-9.
On November 18, 1952, while operating in the Sea of Japan, the USS Oriskany and its carrier group were conducting airstrikes when they sent out F9F Panther jets on a patrol near the North Korean-Chinese border. Royce Williams and his wingman, encountered seven Soviet MiG-15 jets approaching from the Russian mainland.
As the situation escalated, four MiGs opened fire, despite the absence of an official conflict between the nations. Williams engaged in a fierce dogfight against six MiGs that lasted 35 minutes. Despite the MiG-15's superior capabilities, Williams managed to down three aircraft, attributing his success to disciplined training and Soviet errors. Low on ammunition and with significant damage to his plane, Williams was pursued by a remaining MiG. However, the sudden reappearance of his wingman made the remaining MiG-15 to break off.
Barely able to maneuver his damaged Panther, Williams returned to the carrier which was carefully aligned for his landing. His aircraft was covered with 263 hits, this was deemed irreparable and after being stripped it was then pushed overboard.
Bibliography:
- United States Navy Aircraft Since 1911, Gordon Swanborough and Peter M. Bowers, Naval Institute Press, 1990.
- The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.
- Grumman Aircraft Since 1929, Rene J. Francillon, Naval Institute Press, 1989.
- American Combat Planes, 3rd Enlarged Edition, Ray Wagner Doubleday, 1982.