North American F-107

https://en.wikipedia.org/wiki/North_American_F-107

The North American F-107 was North American Aviation's entry in a United States
Air Force tactical fighter-bomber design competition of the 1950s. The F-107 was
based on the F-100 Super Sabre, but included many innovations and radical design
features, notably the over-fuselage air intakes. The competition was eventually
won by the Republic F-105 Thunderchief, and most of the F-107 prototypes ended
their lives as test aircraft. One is on display at the National Museum of the
United States Air Force and a second at Pima Air and Space Museum.

The aircraft's most distinguishing feature is its dorsal-mounted variable-area
inlet duct (VAID). While the VAID was at the time a system unique to the F-107A,
it is now considered to be an early form of variable geometry intake ramp which
automatically controlled the amount of air fed to the jet engine. Although the
preliminary design of the air intake was originally located in a chin position
under the fuselage like the Vought F-8 Crusader, the air intake was eventually
mounted in an unconventional position directly above and just behind the
cockpit. The VAID system proved to be very efficient and NAA used the design
concept on their A-5 Vigilante, XB-70 Valkyrie and XF-108 Rapier designs.

The air intake was in the unusual dorsal location as the Air Force had required
the carriage of an underbelly semi-conformal nuclear weapon. Some sources claim
that the original chin intake caused a shock wave that interfered in launching
this weapon, but no such testing was actually carried out. The implications this
design choice had for the survivability of the pilot during ejection were
troubling. The intake also severely limited rear visibility. Nonetheless this
was not considered terribly important for a tactical fighter-bomber aircraft,
and furthermore it was assumed at the time that air combat would be via guided
missile exchanges outside visual range.

Extensive design changes resulted in its redesignation from F-100B to F-107A
before the first prototype flew. The F-107 was never given an official name, but
was sometimes informally called the "Super Super Sabre" referring to North
American's earlier fighter design, the F-100 Super Sabre. The flight crews
referred to it as the "man eater", in reference to the position of the air
intake directly above the cockpit.

The designation "F-107A" was the only one assigned to the aircraft, though
"YF-107A" is often used in publications.


Role
Fighter-bomber

National origin
United States

Manufacturer
North American Aviation

First flight
10 September 1956

Retired
25 November 1957

Status
Canceled

Primary users
United States Air Force
NACA

Number built
3

Program cost
US$105.8 million

Developed from
North American F-100 Super Sabre

The first F-107A (s/n 55-5118) with North American's chief test pilot Bob Baker
at the controls, made its initial flight on 10 September 1956, attaining Mach
1.03. Although successfully carrying out its flight, the brake chute did not
deploy, which resulted in a "hot" landing with the nose gear strut breaking. The
aircraft first achieved Mach 2 in tests on 3 November 1956.

It was joined by the second F-107A (AF Ser. No. 55-5119), which made its first
flight on 28 November 1956. It was used for weapons testing with both
conventional and atomic bombs. The last prototype, (AF Ser. No. 55-5120) had its
maiden flight on 10 December 1956. At the conclusion of the F-107A's successful
test program, the Tactical Air Command decided to hold a fly-off competition
between the F-107A and the Republic F-105 which was designed to same mission
requirements and used the same engine. Although the competition was close, the
F-105 was selected as the new standard TAC tactical fighter. The three F-107A
prototypes were relegated to test flying while the pre-production order was
cancelled.

In late 1957, prototypes #1 and #3 were leased to the National Advisory
Committee for Aeronautics (NACA) for high-speed flight research. Aircraft #1 is
now in the collection of the Pima Air & Space Museum. In September 1959, with
Scott Crossfield at the controls, aircraft #3 was damaged during an aborted
takeoff. The aircraft was not repaired and, ultimately, used for fire fighting
training and was destroyed in the early 1960s. (55-5120 was also noted to be
stored in poor condition in the Tallmantz collection at Orange County Airport
California in September 1970.)

Prototype #2 was never used for testing, and instead flown on 25 November 1957
to the National Museum of the United States Air Force at Wright-Patterson Air
Force Base near Dayton, Ohio. This aircraft had not been completed and none of
the radio navigation systems had been installed. To fly it to the museum, Major
Clyde Good intended to follow an F-100 being delivered the same day. After an en
route refuelling stop the two aircraft became separated, and Good was forced to
follow roads to the St. Louis area when it turned dark and overcast. The
aircraft was not equipped with cockpit or instrument lighting, so Good
periodically flicked his Zippo lighter to read the instruments. Guessing a
heading, he flew close enough to Dayton to be seen on radar at Wright-Patterson
Air Force Base and was talked down to the runway. It was then that Good
discovered that the landing lights had not been installed either, but he was
able to successfully land the plane while using the Zippo to light the airspeed
indicator through the approach.

Specifications (F-107A)

General characteristics
Crew: one
Length: 61 ft 10 in (18.85 m)
Wingspan: 36 ft 7 in (11.15 m)
Height: 19 ft 8 in (5.89 m)
Wing area: 376 ft² (35 m²)
Empty weight: 22,696 lb (10,295 kg)
Loaded weight: 39,755 lb (18,033 kg)
Max. takeoff weight: 41,537 lb (18,841 kg)
Powerplant: 1 × Pratt & Whitney YJ75-P-9 turbojet, 24,500 lbf (109 kN)

Performance
Maximum speed: Mach 2+ (1295 mph)
Range: 2,428 mi (2,109 nmi, 3,885 km)
Service ceiling: 53,200 ft (16,220 m)
Rate of climb: 39,900 ft/min (203 m/s)
Wing loading: 106 lb/ft² (516 kg/m²)
Thrust/weight: 0.62

Armament

Guns: 4x 20mm Pontiac M39 cannon OR 1x 20mm, 6 barrel M61 Vulcan autocannon
Bombs: 10,000 lb (4,500 kg) on 5 hardpoints; 2 under each wing, 1 semi-recessed
ordnance station under fuselage centerline. Wide variety of ordnance, including
tactical nuclear weapons





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