North American F-107

North American F-107
North American F-107A "Ultra Saber"
Type:	Fighter bomber
Design country:	United States
Manufacturer:	North American Aviation
First flight:	September 10, 1956
Commissioning:	Flight tests ended in 1957
Production time:	Was never mass-produced
Number of pieces:	3

The North American F-107 was a fighter-bomber developed for the US Air Force (USAF) in the mid-1950s , but it did not go into production. The F-107, unofficially also called Ultra Saber , belonged to the so-called Century series ( F-100 to F-110 ).

Development history

F-100B

Middle of 1953 began North American Aviation , the development of an improved version of its new fighter F-100A Super Saber , the F-100B. The model, internally designated as the NA-212, was to be used both as an all-weather and night fighter and as a fighter-bomber with double the speed of sound. The US Air Force was more interested in an advanced fighter-bomber and so on June 11, 1954 placed an order for 33 F-100Bs. North American then no longer pursued the planned interceptor variant (F-100BI). At the same time, the manufacturer also continued to develop its F-100; The next version, the F-100C, also incorporated findings from the fighter-bomber design.

F-107A

Since the original model had to be modified considerably for the new design, the USAF assigned the new designation F-107 in July 1954. The most striking feature of the F-107 design was the engine air intake above the fuselage behind the cockpit. The fin and the spoiler for steering around the longitudinal axis were also unusual. The F-107 had a fold-out ram air turbine on the right front fuselage side, and a fold-out air refueling probe was located on the left fuselage front side. The F-107 had a forward fuselage tank with 560 gallons, an aft fuselage tank with 378 gallons and an integral wing tank each with 262 gallons. A hydraulically extendable rear shock absorber was located under the stern. The F-107 was equipped with a braking parachute and a large air brake flap on both sides of the rear fuselage. In August 1954, the Luftwaffe reduced their order to three prototypes and nine additional test aircraft. The official USAF designation for them was F-107A, which is also how the prototypes were labeled. Nevertheless, only the designation YF-107A can be found in many publications.

The first flight of the first prototype with registration 55-5118 took place on September 10, 1956 at Edwards Air Force Base . The second machine (55-5119) first flew on November 28, 1956. It was intended for testing the weapon system and was therefore the only one equipped with four 20 mm cannons (M39). Finally, on December 20, the third prototype took off for the first time, with the aim of testing the adjustable side walls of the air inlet in particular, in order to achieve an optimal air flow for every speed.

Program stop

Since mid-1956, the F-107, also known unofficially as Ultra Saber , was in discussion as a competitor to the Republic F-105 Thunderchief , which suffered from sometimes considerable development and production problems. Even so, the US Air Force stuck to the F-105 because it would be available sooner. So the F-107 program was stopped in March 1957.

Prototype numbers 1 and 3 went to the Dryden Flight Research Center of the National Advisory Committee for Aeronautics (NACA) (later NASA ) and were used for aerodynamics tests from November 1957 to September 1959. A second focus was experiments with sidestick controls in order to be able to use them in the North American X-15 . On September 1, 1959, an aborted take-off followed by a fire damaged the third aircraft so badly that it was not worth repairing and it was scrapped. Prototype number 1 moved from NASA to the Pima Air Museum in Tucson , Arizona . The second aircraft built remained with the US Air Force and can be viewed today in the USAF Museum at Wright-Patterson Air Force Base . A training version of the F-107 was also planned, called the TF-107. The fuselage in front of the cockpit would have been lengthened (comparable to the Northrop F-5 ), both cockpits would have been covered by a single large canopy.

Armament

The F-107 was equipped with four M-39 on-board cannons. Alternatively, the equipment with two Vulcan on-board cannons M-61 A-1 was proposed. Two weapon pylons were mounted under each wing. Additional tanks (inner stations 275 gallons, outer stations 200 gallons), containers with unguided rockets or free-fall bombs could be attached to these. The hull weapon holder is a special feature. It is located in a semicircular bulge under the central hull. A conventional, round 500-galon additional tank is then half-sunk in the fuselage. There was also a semicircular additional tank for the F-107; when this was mounted on the fuselage station, there was practically no air resistance due to its flattened underside. It was also possible to hang a conventional free-fall bomb directly at this mid-fuselage weapon station. Another option was to mount a "recessed" 250 gallon saddle tank that carried an MK-28 mount for a free-fall bomb. With this combination, however, the saddle tank could not be thrown off.

Technical specifications

The third and final prototype of the F-107A

The F-107A during a test flight

Parameter	Data
Type:	Fighter bomber
Length:	18.85 m
Wingspan:	11.15 m
Wing area:	35 m²
Wing extension :	3.55
Wing loading :	minimum (empty weight): 294 kg / m² nominal (normal takeoff weight): 515 kg / m² maximum (maximum take-off weight): 538 kg / m²
Height:	5.89 m
Empty weight:	10,295 kg
Normal takeoff weight:	18,033 kg
Maximum take-off weight:	18,841 kg
Top speed:	Mach 2+ (with afterburner at optimal height)
Service ceiling:	16,220 m
Rate of climb:	203 m / s
Transfer range:	3,885 km
Engine:	a Pratt & Whitney J75-P-9 jet engine with up to 109.02 kN thrust
Crew:	1 pilot
Armament:	up to 4,500 kg external weapon load

literature

• Anthony L. Buttler: American Secret Projects: Fighters & Interceptors 1945–1978. Midland Publishing, 2007, ISBN 1-85780-264-0 .

Web links

Commons : North American F-107  - collection of pictures, videos and audio files

Individual evidence

1. ^ William J. Simone: North American F-107A (= Air Force Legends . Volume 203). Steve Ginter, 2002, ISBN 0-942612-98-1 .