The Grumman F11F Tiger was the first fighter capable of level supersonic flight to enter service with the US Navy, but suffered from an underpowered engine and was soon replaced by the Vought F8U-1 Crusader.
The Tiger was developed to take advantage of a gap in the US Navy’s fighter programme. In the late 1940s four designs has been ordered – the Douglas F4D Skyray, Chance Vought F7U Cutless, Grumman F10F Jaguar and McDonnell F3H Demon. However all four used underperforming Westinghouse jet engines, and none of them were a success. In 1953 the Navy held a design contest for new day and all weather supersonic fighters, and selected the Grumman F8U/ F-8 Crusader and McDonnel F4H/ F-4 Phantom II. Both of these would go on to be successful designs – the F-8 Crusader remained in service as a naval fighter until 1976 and the F-4 Phantom II remained in combat service in the US until 1996 and in Germany until 2013! However in 1953 both were something of a gamble, with neither company having produced swept wing fighters and McDonnell planning to use another untested engine. In the end the Crusader entered service in 1957 and the Phantom in 1961
In contrast Grumman were in the middle of producing the F9F Cougar, a swept wing development of the earlier F9F Panther and had gained valuable experience from the F10F. They decided to take advantage of the situation to produce a relatively simple supersonic fighter that would be available before either of the more advanced designs
Grumman’s design team produced an aircraft with very thin swept wings produced by milling down aluminium planks. The fuselage was built using the ‘area rule’, giving it a narrow section alongside the wings so the cross section remained equal along the length of the fuselage (also known as the ‘coke bottle’ shape). The tailplane and elevators would be built into the rear fuselage. It would be powered by the Curtiss Wright J-65 engine, which had performed well in the North American FJ Fury and Republic F-84F, although without an afterburner. The new Grumman design would need an afterburner to be designed and tested. The aim was to have an engine that provided 7,800lb normally and 11,000lb with the afterburner. The Tiger was expected to reach Mach 1.21 in level flight.
The Navy was impressed enough with the Grumman design to place an order for three prototypes on 27 April 1953. Funding for the new design had come from the Cougar programme, so the new prototype was designated the YF9F-9. The first prototype made its maiden flight on 30 July 1954 with the Grumman test pilot ‘Corky’ Meyer at the controls, powered by a standard J65-W-7 engine without supercharger. It went supersonic in a shallow dive on its second flight. A few minor problems were detected, but these were soon solved. Two weeks later the aircraft was put on show, and the Navy increased its production order from 42 aircraft to 388 (although this was later reduced to 201).
The second prototype made its maiden flight in October 1954, again without the afterburner. However the first flight by a Navy test pilot, on 20 October 1954, ended with a crash after the engine flamed out and wouldn’t restart. Luckily the pilot survived, but the aircraft ended up in a forest.
The new afterburner finally arrived in January 1955 and was added to the second prototype. It was expected to increase thrust by 50% and greatly improve the aircraft’s rate of climb and high speed performance, which had proved disappointing without it. However the first flight with the afterburner, on 25 January was itself disappointing. The extra thrust was much less than expected, and at mach 1.03 there was an explosion in the afterburner. The aircraft was otherwise undamaged. After landing it was discovered that a hole had been burnt through the side of the afterburner and most of the fuselage. This was the only existing example of the new afterburner, so its loss set the programme back. The next afterburner didn’t arrive until April 1956, and it was still short on power. Top speed in level flight was only Mach 1.05, well down on the contract speed of Mach 1.2. Eventually Curtiss Wright were given a new contract with the lower 10,500lb of thrust written into it, thus reducing the top speed of the Tiger.
In April 1955 the Tiger was redesignated as the F11F, acknowledging that it was a very different aircraft to any version of the F9F. The production aircraft were delivered between 15 November 1954 and 23 January 1959.
The first service unit to receive the Tiger was VA-156 at NAS Moffitt Field, California, which gained its first aircraft in March 1957, two years after originally planned. In the same month VF-32 received the F8U-1 Crusader, which outperformed the Grumman aircraft. As a result the Tiger had a short front line career. They began to go to the Jet Transition Training Units in November 1958, and retired from fleet service in 1961. However they did remain in the training role until 1967.
The longest user of the Tiger was the Blue Angels Flight Demonstration Team, which operated the Tiger from 1957 to 1969, taking advance of its excellent flight control at high G and in rolls and low maintenance requirements.
Although the Tiger hadn’t produced the expected speed, and the development problems meant it had entered service at the same time as the F-8 Crusader, it did have some advantages. It had a very impressive safety record. It was the first Navy jet aircraft to suffer from no accidents during its first year of operation on aircraft carriers. Later, when used as a trainer, it was used to train 84 pilots in its first year, again without an accident. It also needed much less maintenance than other jet fighters of the period, requiring 4-6 man hours of maintenance per hour of flight. Its nearest competitor needed three times that much work.
The F11F-1 became the F-11A in the September 1962 joint designation system, by which time it was only in use with the Blue Angels and as a trainer.
Grumman was well aware of the limits imposed by the engine, and in 1955 suggested fitting a General Electric J79 engine (as used in the F-4 Phantom) to the airframe of the Tiger. The Navy agreed to fund the conversion of two production F11Fs into F11F-1F prototypes. These aircraft were given a YJ79-GE-3 engine, which produced 12,533lb thrust normally and 17,000lb thrust with the afterburner. They were give larger air intakes and a modified wing.
The first prototype made its maiden flight on 25 May 1956, when it reached Mach 1.44, a big increase on the Mach 1.1 of the F11F-1. It was then modified to give it a longer fuselage, a more powerful engine and wing root fillets. In 1957 it reached Mach 2.04, making it the first naval aircraft to go above Mach 2 (greatly exceeding expectations, and also making it twice as fast as the normal Tiger). One of the aircraft also set a world altitude record of 76,932ft with US Navy Lt Commander George Watkins at the controls.
Despite its impressive performance, the F11F-1F wasn’t ordered for the US Navy. Grumman attempted to sell it to Germany, Japan, Canada and Switzerland, but lost out to the Lockheed F-104 Starfighter in most cases and the Dassault Mirage in Switzerland.
Engine: Wright J65-W-18 turbojet
Span: 31ft 7.5in
Length: 46ft 11.25in
Height: 13ft 2.75in
Empty weight: 13,428lb
Gross weight: 22,160lb
Max speed: 750mph at sea level, Mach 1.1 at 35,000ft
Cruising speed: 577mph at 38,000ft
Climb Rate: 5,130ft/ min
Service ceiling: 41,900ft
Range: 1,270 miles
Armament: Four fixed forward firing 20mm guns
Bomb load: Four underwing Sidewinder 1A or 1C air-to-air missiles