Grumman F-9 Cougar

The Grumman F9F/F-9 Cougar is a carrier-based jet-powered fighter aircraft designed and produced by the American aircraft manufacturer Grumman.

It was developed during the early 1950s on behalf of the United States Navy (US Navy) and United States Marine Corps (USMC), which were keen to quickly introduce a naval fighter equipped with a swept wing. Grumman's design team decided to adapt its earlier F9F Panther, replacing the straight wing of the Panther with a new swept wing. Thrust was also increased with the installation of a newer and more powerful engine. Nevertheless, the aircraft remained limited to subsonic speeds. The first prototype (XF9F-6), which was produced by modifying an existing Panther, performed its maiden flight on 20 September 1951. The Navy considered the Cougar to be an updated version of the Panther, despite having a different official name, and thus Cougars started off from F9F-6.

During December 1952, the F9F-6 was introduced to service, VF-32 being the first squadron to receive the type; while developed at a relatively rapid pace, the Cougar's arrival was too late for it to engage in active combat during the Korean War. While initial production aircraft were powered by a single Pratt & Whitney J48 turbojet engine, the F9F-7 were furnished by an Allison J33 powerplant instead. In the mid 1950s, the improved F9F-8 was introduced, which had a lower stall speed, improved handling when flown at high angles of attack, and increased range. The twin-seat F9F-8T was procured by the US Navy to perform various forms of training. The F9F-8P photo-reconnaissance variant was created by converting existing F9F-8s; most of the modifications were made to the aircraft's nose.

On 1 April 1954, US Navy Cougars established a new transcontinental crossing record. The US Navy's flight demonstration team, the Blue Angels, adopted the type in place of its Panthers. The Cougar gained a favourable reputation as a highly maneuverable and easy to fly aircraft. The only foreign air service that operated the Cougar was the Argentine Naval Aviation. The F9F-8 was withdrawn from front-line duties during the late 1950s, having been replaced by more capable aircraft such as the F11F Tigers and F8U Crusaders. While the Naval Reserves flew Cougars into the mid-1960s, only the TF-9J trainer model saw actual combat, having been deployed as a Forward Air Control aircraft during the Vietnam War. Following its withdrawal from active service, many F9F-6s were used as unmanned drones for combat training, designated F9F-6D, or as drone controllers, designated F9F-6K.

Design and development

Early development

Rumors that the Soviet Union had produced a swept wing fighter had circulated a year before the Mikoyan-Gurevich MiG-15 first appeared at air shows in 1949. Despite the level of activity taking place with swept wing aircraft, the US Navy was not initially focused on the development of such aircraft. This was largely because the US Navy's focus at the time was defending the battle group against high speed, high altitude bombers with interceptors, as well as escorting medium-range carrier-based bombers in all weather conditions; air-to-air combat was of less interest at that time. Nonetheless, the US Navy appreciated the importance of getting a capable carrier-based swept wing jet fighter. Grumman was awarded a contract for the development of a swept-wing fighter jet in early 1951. The arrival of the MiG-15, which easily outclassed straight-wing fighters in the air war over North Korea, was a major factor.

Development proceeded at a relatively rapid pace, in part due to Grumman's pre-existing experience of studying prospective derivatives of the Panther guiding several of their design choices.

However, it was necessary to implement various design changes. To effectively accommodate the switch from a straight wing to a swept one, it was necessary to delete the two 120-gallon tip tanks, as in combination with the swept wing there would have been too great a negative impact upon the aircraft's center of gravity; for the same reason, only a single hardpoint was fitted under each wing. In a full-power vertical dive, it could break the sound barrier without experiencing buffeting or major undesirable flight characteristics. In level flight, the aircraft remained only capable of subsonic flight, however, the critical Mach number was increased from 0.79 to 0.86 at sea level, and to 0.895 at 35,000 ft (10,000 m), thus delivering performance markedly superior to that of its predecessor. As such, the Cougar was capable of flying safely and easily even without the upper portion of the tail being present.

F9F-6

thumb|An F9F-6 of [[VFA-211 (U.S. Navy)|VF-24 on in 1955]]

The initial production model was the F9F-6; a total of 646 airframes were delivered between mid-1952 and July 1954. The F9F-6 first flew on 20 September 1951, seven months after Grumman signed a contract with the Navy for swept-wing fighter. The engine was the Pratt & Whitney J42, a licensed version of the Rolls-Royce Nene. The first 30 production aircraft had the same J42 P-6 engine as the F9F-5; the rest had the more powerful J42 P-8 with of thrust.

Armament was four 20 mm (.79 in) AN/M3 cannons in the nose and provisions for two bombs or drop tanks under the wings. Most were fitted with a UHF homing antenna under the nose, and some were fitted with probes for inflight refuelling. The F9F-6 used an Aero 5D-1 weapons sight with an APG-30A gun-ranging radar. The F9F-6 was later designated F-9F in 1962. Sixty were built as F9F-6P reconnaissance aircraft with cameras instead of the nose cannon.

After withdrawal from active service, many F9F-6s were used as unmanned drones for combat training, designated F9F-6D, or as drone controllers, designated F9F-6K.

Flexible deck testing

The Navy used two modified F9F-7s to conduct experiments landing on British-inspired flexible decks which did not require the use of landing gear. The reasoning was that since an airplane's landing gear comprises some 33% of the total weight, a plane without landing gear would gain a greater range and would be able to carry more ordnance. The planes were launched using a ramp and a handling dolly which served as temporary landing gear. The two F9F-7 aircraft in the test were equipped with the powerful J48-P8 engine instead of the Allison J33 engine originally used with the F9F-7. While the landing tests yielded positive results and proved that landing was clearly possible, the project was terminated in 1955 as it would have been difficult to move the aircraft around the carrier deck once they landed. It also required a highly skilled pilot to perform the landings and would have made it impossible to divert to a land base if necessary.

F9F-8

Work on the F9F-8 began in April 1953 with three goals: lower the airplane's stall speed, improve aircraft control at high angles of attack, and increase range. It featured an 8 in (20 cm) stretch in the fuselage and modified wings with a greater chord, an increased area (from ), and a dogtooth. The airframe changes improved low-speed and high angle of attack flying, and gave more room for fuel tanks. The top speed was and minimum catapult speed was lowered to . It also was now capable of breaking the sound barrier in a steep dive. All four ammunition boxes were mounted above the guns, in contrast to the split location of most previous F9Fs including the Panther. Visibility, which was already very good was improved with the F9F-8. 601 aircraft were delivered between April 1954 and March 1957. Late production F9F-8 aircraft were given the ability to carry four AIM-9 Sidewinder air-to-air missiles under the wings (the first Navy aircraft to deploy with the missiles). Most earlier aircraft were later modified to carry Sidewinders. A number were given also nuclear bombing equipment. The F9F-8 was redesignated F-9J in 1962. The F9F-8B aircraft were F9F-8s converted into attack fighters, later redesignated AF-9J. The Navy acquired 377 two-seat F9F-8T trainers between 1956 and 1960. They were used for advanced training, weapons training, and carrier training, and served until 1974. They were armed with twin 20 mm (.79 in) cannon and could carry a full bombs or missiles load. In the 1962 redesignation, these were later called TF-9J.

thumb|The F9F-8 was fitted with an inflight refueling probe and [[AIM-9 Sidewinder|Sidewinder missiles.]]

Aerial reconnaissance

A total of 110 F9F-8Ps (photo-reconnaissance) were produced with an extensively modified nose carrying cameras. They were withdrawn after 1960 to reserve squadrons. In 1962, remaining F9F-6P and F9F-8P aircraft were re-designated RF-9F and RF-9J respectively.

Modifications of F9F-8 to convert to F9F-8P:

The modification to eliminate the guns and related equipment, while incorporating the photographic equipment, automatic pilot, and their controls and instruments, has resulted in the following changes:
Rearrangement of electronics equipment installed in the area enclosed by the fuselage nose section, lengthening of this section by , and shortening of the sliding nose section.
Rearrangement of the left and right consoles and the main instrument panel to provide space for the controls associated with the additional equipment.
Some minor changes of the fuselage structure and equipment installations to provide for the necessary ducting control for hot air from the engine compressor, which is used for defrosting the camera windows and heating the camera compartment.
Removal of all armament, the Armament Control System, and the AN/APG-30 radar system, and installation of an additional armor plate bulkhead.

Flight characteristics and deployment

The F9F was known to be highly maneuverable and easy to fly.

The F9F Cougar was also a capable multi-role aircraft, which may explain why it was deployed less often than dedicated fighters.

Operational history

thumb|A TF-9J (F9F-8T) of [[Marine Aircraft Group 13|H&MS-13 at Chu Lai, Vietnam 1967]]

thumb|Blue Angel F9F-8's performing a "[[fleur-de-lis" maneuver in 1955]]

United States

The first F9F-6s were assigned to fleet squadron VF-32 at the end of 1952. The first F9F Cougar squadron to actually deploy was VF-24, assigned to in August 1953. It arrived too late to the Korean theater to participate in the air war.

The TF-9J two-seat trainer had a long service with the U.S. Navy. It served as the Navy's advanced flight trainer for more than two decades.

Blue Angels

The U.S. Navy's flight demonstration team, the Blue Angels flew four different variants of F9Fs from the F9F-2 Panther to the F9F-8. The Blue Angels replaced their six F9F-5 Panthers with six F9F-6s in 1953. This was short lived however and the Navy subsequently took them for fleet use without using the planes in an air show. The F9F-6s were then replaced with overhauled F9F-5s until 1954 when the Blue Angels switched to the F9F-8. The Blue Angels used the F9F-8 until 1957 they were replaced by the Grumman F11F-1 Tiger, although one two-seat F9F-8T was retained for press and VIP flights.

Argentina

The only foreign air arm to use the F9F Cougar was the Argentine Naval Aviation, who also used the F9F Panther as well. Two F9F-8T trainers were acquired in 1962, and served until 1971. The Cougar was the first jet to break the sound barrier in Argentina. One aircraft (serial 3-A-151) is on display at the Naval Aviation Museum (MUAN) at Bahía Blanca, while the other was sold to a customer in the United States and subsequently lost in an accident on 31 October 1991.

United States

;F9F-6

126670 – in storage at the National Air and Space Museum, Paul E. Garber Preservation, Restoration, and Storage Facility, Suitland, Maryland.
128109 – National Naval Aviation Museum at NAS Pensacola, Florida.
127236 – New Iberia Veterans Memorial Building, New Iberia, Louisiana.

;F9F-6P

unknown – The Town of Tonawanda Veterans Memorial in the Town of Tonawanda, New York. The aircraft has been on display since 1959 and in 2009 was refurbished when the new Town of Tonawanda Veterans Memorial was created.

;F9F-7

130763 – Cradle of Aviation Museum in Garden City, New York.

;F9F-8

131063 – Texas Air Museum in Slaton, Texas.
131230 – National Naval Aviation Museum, NAS Pensacola, Florida.
138876 – Pueblo Weisbrod Aircraft Museum in Pueblo, Colorado.
141117 – Intrepid Sea-Air-Space Museum in New York, New York. It is on loan from the National Museum of Naval Aviation. It was built in Grumman's Bethpage factory in 1955 and retired from active service in 1965. It previously served as a gate guard for Naval Weapons Station Earle, and later was displayed at a playground in Wall Township, NJ. Restored to wear the colors of fighter squadron VF-61, which flew from in 1956.
141121 – Pima Air & Space Museum, adjacent to Davis-Monthan AFB, in Tucson, Arizona.
146417 – Evergreen Aviation & Space Museum in McMinnville, Oregon. It is on loan from the National Museum of Naval Aviation and is painted to represent the narrator's aircraft for the U.S. Navy Blue Angels precision flight demonstration team.

;F9F-8B

144275 – Patuxent River Naval Air Museum in Lexington Park, Maryland.
141702 – USS Midway Museum in San Diego, California.
141722 – Flying Leatherneck Aviation Museum, MCAS Miramar in San Diego, California.
144388 – Estrella Warbird Museum in Paso Robles, California.
144426 – Pima Air & Space Museum, adjacent to Davis-Monthan AFB in Tucson, Arizona.
144402 – Military Aviation Preservation Society, M.A.P.S. in Canton, Ohio.
144406 – Privately owned by Mike Kellner, in Marengo, Illinois.

;F9F-8T

142442 – The Town of Woodridge, New York.
147276 – USS Lexington Museum in Corpus Christi, Texas.
147283 – Air Zoo in Kalamazoo, Michigan.
147385 – at the Patriot's Point Naval and Maritime Museum in Mount Pleasant, South Carolina.
147397 – Pima Air & Space Museum, adjacent to Davis-Monthan AFB in Tucson, Arizona.
142985 – Hickory Aviation Museum, Hickory Regional Airport (KHKY) in Hickory, North Carolina.
147418 – James Clemens High School part of the Madison City Schools district in Madison, Alabama.

Specifications (F9F-6/F-9F)

frameless|right|3-view line drawing of the Grumman F9F-8 Cougar