North American F-107

What was the North American F-107?

The F-107 was a single-seat, Mach 2 fighter-bomber that North American Aviation built in the mid-1950s. It was a heavily reworked descendant of the F-100 Super Sabre, which is why crews and writers called it the “Ultra Sabre” or the “Super Super Sabre.”

It flew in 1956 and was cancelled within about a year. Only three were built, and two survive in museums.

Origins: from F-100B to F-107A

In June 1953, North American began an in-house study of advanced F-100 derivatives. The work centered on a fighter-bomber known as the F-100B, aimed at a USAF tactical fighter-bomber requirement.

In August 1954 the Air Force signed a contract for three prototypes, with a pre-production order for six more. The aircraft was redesignated F-107A before the first one flew. “YF-107A” appears in many books, but F-107A was the only designation ever assigned.

The intake above the cockpit

The F-107’s most striking feature was its air intake. The F-100’s nose intake was deleted and replaced by a variable-area inlet duct directly above and behind the cockpit.

The reason was the mission. Moving the intake out of the nose cleared the belly for a semi-recessed nuclear weapon. The layout earned the jet a “man-eater” nickname among enthusiasts, and it is the first thing most people notice in photos.

The pilot entered through a vertically opening canopy, and the ejection seat was designed to blast through it. Roll control came from spoilers rather than ailerons, and the vertical tail was a one-piece movable surface.

Power came from a single Pratt & Whitney J75, about 50% more thrust than the F-100’s engine.

Flight testing: Mach 2 in the first two months

Chief test pilot Bob Baker flew the first F-107A, serial 55-5118, on September 10, 1956. It reached Mach 1.03 on that flight, though the brake chute did not deploy and a hot landing broke the nose gear strut.

The same aircraft first reached Mach 2 on November 3, 1956. The second aircraft, 55-5119, flew on November 28, 1956, and was used for conventional and atomic weapons testing. The third, 55-5120, followed on December 10, 1956.

Armament

The F-107 was designed to carry four 20 mm Pontiac M39 cannon, or a single 20 mm M61 Vulcan. Up to 10,000 lb (4,500 kg) of bombs could go on five hardpoints: two under each wing and one semi-recessed station under the fuselage. That included tactical nuclear weapons.

Why the F-107 lost to the F-105

After the test program, Tactical Air Command held a fly-off between the F-107A and the Republic F-105 Thunderchief. Both met the same requirement and used the same J75 engine family. The contest was close, but the F-105 was chosen as TAC’s standard tactical fighter.

The Air Force had ordered the F-105 into production in March 1956, about six months before the F-107 flew. The F-105 also had a fully internal bomb bay and carried more ordnance, and ceiling and climb mattered less for low-level strike missions.

Company circumstances played a part too. Republic was finishing F-84 production with little else in hand, while North American was already busy with the A-5, XB-70 and XF-108.

The pre-production order was cancelled and the three prototypes became test aircraft. For the aircraft that did get built, see the Republic F-105 Thunderchief page.

Later life: NACA research and the survivors

In late 1957, the first and third prototypes were leased to NACA for high-speed research. In September 1959, Scott Crossfield was flying the third aircraft when an aborted takeoff damaged it. He survived, the jet was not repaired, and it was later used for firefighting training and destroyed in the early 1960s.

Two F-107s survive. Serial 55-5118 is at the Pima Air & Space Museum near Tucson, Arizona. Serial 55-5119 flew to the National Museum of the U.S. Air Force at Wright-Patterson AFB on November 25, 1957, and is held there.

Understanding the numbers

The full specification table for the aircraft is on this page. A few figures need context.

The maximum speed is listed as Mach 2, and the first prototype first reached that on November 3, 1956. The ceiling and climb rate are design figures for the F-107A, and supporters of the jet cite them as advantages over the F-105.

The ordnance load of 10,000 lb is separate from the payload row, which is a different stored figure. Treat both as period estimates, since only three aircraft ever flew.

Frequently Asked Questions

How many F-107s were built?

Three F-107As were built. Nine prototypes were originally ordered, but only three were completed, with serials 55-5118, 55-5119 and 55-5120.

Why was the F-107 cancelled?

The Air Force chose the Republic F-105 Thunderchief as its standard tactical fighter after a fly-off. The F-105 was already ordered into production, had a fully internal bomb bay and carried more ordnance. The F-107 pre-production order was cancelled.

Why is the F-107’s intake above the cockpit?

Placing the inlet duct behind the canopy cleared the belly of the aircraft for a semi-recessed nuclear weapon. It replaced the F-100’s nose intake.

How fast was the F-107?

It is listed as a Mach 2 aircraft. The first prototype first reached Mach 2 on November 3, 1956, about two months after its first flight.

Where can you see an F-107 today?

Serial 55-5118 is at the Pima Air & Space Museum in Tucson, Arizona. Serial 55-5119 belongs to the National Museum of the U.S. Air Force at Wright-Patterson AFB near Dayton, Ohio.

Was the F-107 the same as the F-100?

No. It was derived from the F-100 Super Sabre, but it was a new design with a different intake, controls and a far more powerful J75 engine.