Century Series Wannabe
North American F-107A
- By Stephan Wilkinson
- Air & Space magazine, July 2010
Depending on who’s talking, the North American F-107A was either the best fighter the Air Force didn’t have the sense to buy, or a politically flawed loser from the outset.
The F-107A will be remembered forever, if it is remembered at all, for being configured as no jet had been before or since: the sharp-edged maw of its air intake, feeding a prototype Pratt & Whitney YJ-75 engine, was just above and behind the cockpit, giving the otherwise sleek fighter the look of a fourth grader with an oversize backpack. In an era of dart-like Mirages and Delta Daggers, the F-107A was a single-engine-jet Winnebago.
The F-107As were built during the mid-1950s paroxysm of fighter/interceptor/fighter-bomber development that resulted in what came to be called the Century Series—all with -100 designations—which, except for the initial un-Area Ruled Convair F-102s, were the first reliably supersonic Air Force jets.
In the 1950s, every service but the Boy Scouts seemed to want nuclear-strike capability. And not only were the Air Force, Navy, and Army all competing to deliver The Bomb, within the Air Force, both Strategic and Tactical Air Commands wanted nuclear bombers, whether they were strategic goliaths or small tactical fighter-bombers. So rather than a bomb bay, the -107 had a kind of belly pouch that could half-cradle a hydrogen bomb to drop at Mach 2 from altitude or deliver from an under-the-radar approach.
That’s why the intake was piggyback. A conventional nose inlet would have required an internal air duct that would interfere with the centerline weapons station. Wing-root intakes that bracketed the bomb might have worked, but North American thought the dorsal tunnel straight back to the engine was a neater solution. (Some have claimed that wind tunnel tests showed airflow around a nose intake would interfere with bomb release, but no such testing was ever done on an F-107A.)
The -107A’s inlet ducting had panels that automatically choked off or opened the inlet to allow the proper amount of air to the engine at everything from double-supersonic to runway-approach speeds. The fighter-bomber lacked conventional flight control surfaces: Roll was controlled by spoilers rather than ailerons, an all-moving vertical fin instead of a
separate stabilizer and rudder worked yaw, and the horizontal stabilizer for pitch control was also an all-moving unit.
In his 2002 book, North American F-107A, William J. Simone recounts one of the hairiest F-107A flights, which was made outside the testing program. Air Force Major Clyde Good delivered the number-two airplane to the Air Force museum in Dayton, Ohio, in November 1957. Good’s -107A, by then almost ready for the scrap yard, had no navigation radios, so he planned a day trip to follow an F-100 Super Sabre from Edwards Air Force Base in California to Wright-Patterson Air Force Base, where the museum is located.