Tag Archives: General Dynamics FB-111A

21 December 1964

Dick Johnson and Val Prahl made the first flight of the General Dynamics F-111A, 63-9766, from Carswell Air Force Base, Fort Worth, Texas, 21 December 1964. (U.S. Air Force)
Dick Johnson and Val Prahl made the first flight of the General Dynamics F-111A, 63-9766, from Carswell Air Force Base, Fort Worth, Texas, 21 December 1964. (U.S. Air Force)

21 December 1964: At 3:25 p.m., Central Standard Time (21:25 UTC), the prototype General Dynamics F-111A, 63-9766 (s/n A1-01), took off from Carswell Air Force Base, Fort Worth, Texas, on its first flight. In the cockpit were test pilots Richard Lowe Johnson and Val Edward Prahl. The airplane rotated (lifted the nose wheel from the runaway) after 2,500 feet (762 meters) and lifted off after approximately 3,000 feet (914 meters). It had been preceded into the air by five chase planes. The takeoff was observed by hundreds of General Dynamics employees, members of the public who lined airport perimeter, and Eugene Martin Zuckert, Secretary of the Air Force.

The F-111A climbed to 10,000 feet (3,048 meters) and the pilots cycled landing gear. Johnson later said, “I have flown several other planes [Convair YF-102 and F-106A] on their first flight and none of the others were able to retract the landing gear the first time out.”

The wings remained at the 26° sweep setting throughout the flight, representing an “average” wing setting.

Because of several compressor stalls and a flap malfunction, the flight was limited to 21 minutes instead of the scheduled 40. Landing speed was only 130 miles per hour (209 kilometers per hour), approximately 50 miles per hour (80 kilometers per hour) slower than current fighters. The faulty flap was caused by a “kinked” spring an an electrical brake switch. Project Chief J. T. Cosby explained that, “The brake keeps the flap from moving after they are positioned. The brake locked when the flaps were lowered to the 35° position for takeoff and stayed locked.” Because of this, the F-111A’s speed limited to 215 miles per hour (346 kilometers per hour) on this flight. After landing, the problem was diagnosed and repaired within two hours.

Following the flight, Dick Johnson was quoted as saying that he was “a little bit more than pleasantly surprised at the takeoff and landing performance. The plane handled extremely well on both takeoff and landing. I felt I had power to spare.”

Richard Lowe Johnson (left) and Val Edward Prahl. (Fort Worth Star-Telegram, Vol. 84, Number 326, Tuesday, 22 December 1964, Page 9, Columns 3–4)
Richard Lowe Johnson (left) and Val Edward Prahl. (Fort Worth Star-Telegram, Vol. 84, Number 326, Tuesday, 22 December 1964, Page 9, Columns 3–4)

On the F-111A’s second test flight, 6 January 1965, wings swept from 16° to 72.5°.

A General Dynamics F-111A demonstrates its variable sweep wing. (U.S. Air Force)

63-9766 had been rolled out of the General Dynamics assembly plant on 15 October 1964.

General Dynamics F-111A 63-9766, rollout 15 October 1964. (U.S. Air Force 061003-F-1234S-002)
General Dynamics F-111A 63-9766, rollout 15 October 1964. (U.S. Air Force 061003-F-1234S-002)

The General Dynamics F-111A is a large twin-engine strike fighter with variable-sweep wings produced for the U.S. Air Force. A second variant, the F-111B, made its first flight 18 May 1965. It was intended for the U.S. Navy as an interceptor, but proved to be too heavy to operate from aircraft carriers and was not put into production.

The F-111 was a result of Secretary of Defense Robert S. McNamara’s controversial “TFX” program which would use a single aircraft for both the Air Force and Navy as a fighter, interceptor, tactical fighter bomber, and strategic nuclear-armed bomber. Trying to make a single aircraft perform these different missions resulted in very high cost overruns, and the aircraft gained a negative perception in the news media. The F-111A and its follow-on, the FB-111 “Aardvark,” however, proved to be very effective in precision strike missions.

General Dynamics F-111A 63-9766 with wings partially swept. (U.S. Air Force)
General Dynamics F-111A 63-9766 with wings partially swept. (U.S. Air Force)

The F-111A was flown by two pilots seated side-by-side in the cockpit. Pre-production aircraft were equipped with ejection seats, but production aircraft had a crew escape module which protected the pilots from the effects of supersonic speed.

The airplane incorporated a state-of-the art terrain-following radar and and inertial guidance computer system that allowed it to fly at a constant height above the ground. The radar searched ahead and to the sides of the aircraft’s flight path and the computer calculated pitch angles to clear obstacles ahead. The system could be programmed to fly the aircraft as low as 200 feet (61 meters) above the ground. These “nap of the earth” profiles allowed the F-111A to avoid detection by radar.

Cockpit of an early General Dynamics F-111A. Note the ejector seats. (U.S. Air Force 061003-F-1234S-015)

The F-111A is 73 feet, 10.6 inches (22.520 meters) long. With the wings fully extended, their span is 63 feet, 0.0 inches (19.202 meters), and fully swept, 31 feet, 11.4 inches (9.738 meters). The airplane has an overall height of 17 feet 1.4 inches (5.217meters). The wings are capable of being swept from 16° to 72.5°. Roll control is transferred to the stabilators when the wings sweep to 42°. It has an empty weight of 46,172 pounds (20,943 kilograms) and maximum takeoff weight of 92,657 pounds (42,029 kilograms).

A Pratt & Whitney TF30 turbofan engine at NASA’s Propulsion Systems Laboratory, 1967. L-R are engineers Fred Looft and Robert Godman. (NASA Glenn Research Center)

Early production F-111As were powered by two Pratt & Whitney TF30-P-1 afterburning turbofan engines, with following aircraft powered by the TF30-P-3. Both are two-spool axial-flow engines with a 3-stage fan section, 13-stage compressor (6 low- and 7 high-pressure stages) and 4-stage turbine (1 high- and 3 low-pressure stages). Both engines are rated at 10,750 pounds of thrust (47.82 kilonewtons), and 18,500 pounds of thrust (82.29 kilonewtons) with afterburner. Both the -1 and -3 engines are 19 feet, 7.5 inches (5.982 meters) long, 4 feet, 0.0 inches (1.219 meters) in diameter, and weigh 3,869 pounds (1,755 kilograms).

The F-111A had a maximum speed of Mach 1.2 at Sea Level, (913 miles per hour/1,225 kilometers per hour), and Mach 2.2 (1,452 miles per hour/2,336 kilometers per hour) at 60,000 feet (18,288 meters). With 5,015.5 gallons (18,985.7 liters) of internal fuel, its range was 3,165 miles (5,094 kilometers). The aircraft could carry external fuel tanks and was capable of inflight refueling.

The F-111A was designed to carry either conventional or nuclear weapons. It has an internal bomb bay, one hardpoint under the fuselage, and four hardpoints under each wing. With the wings swept to 72.5°, it could carry 18 M117 bombs, but when extended to 26°, it could carry as many as 50. On a nuclear strike mission it could carry the B61 thermonuclear bomb. A General Electric M61A1 Vulcan 20 mm rotary cannon could be installed in the bomb bay, with 2,000 rounds of ammunition..

159 F-111As were built, including 18 pre-production aircraft.

General Dynamics F-111B Bu. No. 151970 (s/n A2-01), the U.S. Navy variant, over Long Island, New York, circa 1965. (National Museum of Naval Aviation 2011.003.299.002)

The prototype General Dynamics F-111A is displayed at the Air Force Flight Test Center Museum at Edwards Air Force Base, California.

General Dynamics F-111A 63-9766 at the Air Force Flight Test Museum,  Edwards Air Force Base, California. (Kerry Taylor/Flickr)

A further development of the F-111A, the FB-111A, made its first flight at Carswell on 13 July 1968. It used the larger wing of the F-111B, with stronger landing gear, an enlarged bomb bay and more powerful engines. The FB-111 is known as the “Aardvark.”

© 2023 Bryan R. Swopes

13 July 1968

General Dynamics FB-111A 67-0159, the first production aircraft. (U.S. Air Force)

13 July 1968: The first production General Dynamics FB-111A supersonic strategic bomber successfully completed a 30-minute maiden flight at Carswell Air Force Base, Fort Worth, Texas. The FB-111A differed from the F-111A fighter bomber with the substitution of a larger wing, originally designed for the F-111B, giving the bomber a 7 foot (2.134 meter) increase in wingspan. The landing gear was strengthened, the bomb bay enlarged, and it had more powerful engines.

Aardvark (Orycteropus afer)

The airplane’s very long nose earned the nickname “Aardvark,” but this did not become official until 1996.

67-0159 was delivered to the U.S. Air Force 4 September 1968 and assigned to the Air Force Flight Test Center, Edwards Air Force Base, California. (The first six production airplanes were used for flight testing.)

67-0159 was later converted to the F-111G configuration. In 1980 it was sent to the Sacramento Air Logistics Center to test weapons modifications and received a spectacular white and orange paint scheme. It was retired in 1990. 67-0159 is in the collection of the National Museum of the United States Air Force. It is on loan and now on display at the Aerospace Museum of California, Sacramento, California.

General Dynamics FB-111A-CF (F-111G) 67-159

The General Dynamics FB-111A is a two-place, twin-engine, strategic bomber with variable-sweep wings, assigned to the Strategic Air Command. It is 73.54 feet (22.415 meters) long. The wingspan varies from a maximum 70.0 feet (21.336 meters) when fully extended, and a minimum 33.96 feet (10.351 meters) when swept fully aft. Overall height is 17.04 feet (5.194 meters).

The wings of the FB-111A have a total area of 550 square feet (51.10 square meters). When fully extended, the wings’ leading edges are swept aft to 16.0°. The angle of incidence at the root is +1° and -3° at the tip. There is 1.0° dihedral.

The Aardvark’s empty weight is 47,481 pounds (21,537 kilograms). Normal maximum takeoff weight is 116,115 pounds (52,669 kilograms), and the maximum overload takeoff weight is or 119,243 pounds (54,088 kilograms).

The aircraft is powered by two Pratt & Whitney TF30-P-107 engines. This is a two-spool axial-flow turbofan engine with afterburner. It has a 3-stage fan section, 13-stage compressor section (6 low- and 7 high-pressure stages) and 4-stage turbine (1 high- and 3 low-pressure stages). The -107 has a maximum continuous power rating of 10,800 pounds of thrust (48.041 kilonewtons) at 14,150 r.p.m., N2 (static thrust, at Sea Level), and a maximum power rating of 20,350 pounds (90.521 kilonewtons) at 14,550 r.p.m., N2 (45 minute limit) The T30-P-107 is 3 feet, 2.12 inches (0.968 meters) in diameter, 20 feet, 1.4 inches (6.132 meters) long,  and weighs 4,121 pounds (1,869 kilograms).

The FB-111A has an average cruise speed of 415–442 knots (478–509 miles per hour/769-819 kilometers per hour), depending on the mission profile. It’s maximum speed at 50,000 feet (15,240 meters) is 1,262 knots (1,452 miles per hour/2,337 kilometers per hour)—Mach 2.20. The bomber’s service ceiling varies from 50,390 feet to 56,380 feet (15,359–17,185 meters), again, depending on the mission profile. The maximum combat range is 4,920 nautical miles (5,662 statute miles/9,112 kilometers). The airplane can carry as many as six 600 gallon (2,271 liter) external tanks on underwing pylons. This gives the Aardvark a maximum ferry range of 4,313 nautical miles (4,963 statute miles/7,988 kilometers).

General Dynamics FB-111A 67-0159. (fb111.net)
General Dynamics F-111A 66-0011, a test airplane in the FB-111A program, loaded with four AGM-69 SRAM missiles. The dots on the missiles and airplane are for precise tracking from ground stations. (U.S. Air Force)

The FB-111A could carry weapons in an internal bomb bay or on underwing hardpoints. It could be armed with up to 37,500 pounds (17,010 kilograms) of conventional bombs; or six AGM-69A Short Range Attack Missiles (SRAM). The Aardvark could carry maximum of six nuclear weapons (B-43, B-57 or B-61).

General Dynamics YFB-111A 63-9783, the prototype strategic bomber variant. (U.S. Air Force)

In addition to a prototype (63-9783, which was converted from the last production F-111A) General Dynamics built 76 FB-111A strategic bombers. With the introduction of the Rockwell B-1B Lancer, the FB-111As remaining in service were converted to F-111G tactical fighter bombers. They were retired by 2003.

The Royal Australian Air Force bought 15 of the F-111Gs. By 2007, these had also been taken out of service.

Two General Dynamics FB-111As in formation, 1 December 1983. (MSGT Buster Kellum, U.S. Air Force)

© 2018, Bryan R. Swopes