The Jaguar that Couldn’t

The Grumman F-14 Tomcat and several Soviet-era fighter aircraft had outstanding performance in large part because of their variable-sweep or “swing” wings. Their wings extended for landing, takeoff, and cruise flight and “tucked in” close to the fuselage for high-speed flight. The world’s first swing-wing combat aircraft was the U.S. Navy-Grumman XF10F-1 Jaguar.

In World War II, Germany had developed the swing-wing prototype Messerschmitt P.1101. The P.1101’s wings could be set at three preselected angles, but they could be adjusted only while the aircraft was on the ground. The incomplete prototype was seized by U.S. troops a few months prior to the end of the war and became the basis for the Bell X-5.¹

Messerschmitt’s chief aerodynamicist, Josef J. Hubert, came to the United States after the war and was a major influence in Grumman’s interest in swing-wing aircraft. The U.S. Air Force−funded Bell X-5 first flew in June 1951 and could adjust wing angles to three positions while in flight.

The Grumman Corporation had a long line of outstanding Navy fighter aircraft—the biwing “bullets,” F4F Wildcat, F6F Hellcat, and F9F Panther and Cougar. By 1947, however, it was apparent that future fighter aircraft would be jet propelled and have swept-back wings to delay the inherent drag and control problems as supersonic speed was approached. But that wing configuration would cause problems during low-speed landing on board aircraft carriers. In addition, catapults at that time could not handle heavy, jet-propelled aircraft with swept-back wings.

Interestingly, the original F10F project was to provide a fixed, swept-wing fighter, with two prototypes ordered from Grumman on 4 March 1948. But several design changes were proposed, and on 7 July 1949, Grumman advanced the idea of a swing-wing configuration. The Navy approved, and in December 1950, the contract with Grumman was revised to provide two variable-wing prototypes.

The wings could be swept hydraulically while in flight from 13.5 degrees to 42.5 degrees. The wings had high-lift features in the form of full-span leading edge slats and flaps along most of the trailing edge. The wings folded for carrier stowage. The aircraft would be powered by a Westinghouse turbojet with afterburner. Armament was to consist of the Navy’s standard four 20-mm Mk 12 cannon, with provisions for 48 2.75-inch or 12 5-inch rockets, or two 2,000-pounds bombs on wing racks.

The first XF10F-1 was completed in March 1952, and after taxiing runs at Bethpage, Long Island, was dismantled and flown to Edwards Air Force Base in California in a C-124 Globemaster. Its first flight was on 19 May with Grumman test pilot C. H. (Corky) Meyer at the controls—the only man to fly the aircraft.

According to Meyer:

In so far as the achievement of this primary aim was concerned, the F10F programme may be considered to have been a resounding success. We eventually brought the stalling speed down to 78 knots, this representing fantastic lift coefficient for an airplane weighing 31,500 lbs with a mere 6,800 [pounds] of installed thrust.²

The Navy ordered several additional prototypes and 100 production aircraft. There were problems with the XF10F-1 controls and systems, however, and, finally, problems with the J40 engine led to conclusion of the flight test program on 25 April 1953, after 32 flights.

The program was canceled. There was the single flying prototype and a second aircraft some 90 percent complete. They were expended in crash barrier tests, and a static test airframe became a gunnery target.

The Jaguar was an aircraft ahead of its time—an aerodynamic concept that available technology could not support. But the technology and Grumman know-how were available for the remarkable F-14 Tomcat, which first flew on 21 December 1970.³