Convair F-102 Delta Dagger

The Convair F-102 Delta Dagger was an American interceptor aircraft that was built as part of the backbone of the United States Air Force's air defenses in the late 1950s. Entering service in 1956, its main purpose was to intercept invading Soviet strategic bomber fleets (Tupolev Tu-95) during the Cold War. Designed and manufactured by Convair, 1,000 F-102s were built.

A member of the Century Series, the F-102 was the USAF's first operational supersonic interceptor and delta-wing fighter. It used an internal weapons bay to carry both guided missiles and rockets. As originally designed, it could not achieve Mach 1 supersonic flight until redesigned with area ruling. The F-102 replaced subsonic fighter types such as the Northrop F-89 Scorpion, and by the 1960s, it saw limited service in the Vietnam War in bomber escort and ground-attack roles. It was supplemented by McDonnell F-101 Voodoos and, later, by McDonnell Douglas F-4 Phantom IIs.

Many of the F-102s were transferred from the active duty Air Force to the Air National Guard by the mid-to-late 1960s, and with the exception of those examples converted to unmanned QF-102 Full Scale Aerial Target (FSAT) drones, the type was totally retired from operational service in 1976. The follow-on replacement was the Mach-2 Convair F-106 Delta Dart, which was an extensive redesign of the F-102.

Convair F-102 Delta Dagger
Class Aircraft
Type Fighter
Manufacturer Convair
Origin United States of America
Country Name Origin Year
United States of America 1953
Country Name Operational Year Retirement Year
United States of America View
ManufacturerName Production From Production To Quantity
Convair 1000 View

On 8 October 1948, the board of senior officers of the U.S. Air Force (USAF) made recommendations that the service organize a competition for a new interceptor scheduled to enter service in 1954; as such, the all-new design would initially be dubbed the "1954 Ultimate Interceptor". Four months later, on 4 February 1949, the USAF approved the recommendation and prepared to hold the competition the following year. In November 1949, the Air Force decided that the new aircraft would be built around a fire-control system (FCS). The FCS was to be designed before the airframe to ensure compatibility. The airframe and FCS together were called the weapon system.

In January 1950, the USAF Air Materiel Command issued request for proposals (RFPs) to 50 companies for the FCS, of which 18 responded. By May, the list was revised downward to 10. Meanwhile, a board at the U.S. Department of Defense headed by Major General Gordon P. Saville reviewed the proposals, and distributed some to the George E. Valley-led Air Defense Engineering Committee. Following recommendations by the committee to the Saville Board, the proposals were further reduced to two competitors, Hughes Aircraft and North American Aviation. Although the Valley Committee thought it was best to award the contract to both companies, Hughes was chosen by Saville and his team on 2 October 1950.

Proposals for the airframe were issued on 18 June 1950, and in January 1951 six manufacturers responded. On 2 July 1954, three companies, Convair, Republic and Lockheed won the right to build a mockup. Until then, Convair had done research into delta-winged aircraft, experimenting with different designs, two of which fell under the name P-92. Of the three, the best design was to win the production contract under the name "Project MX-1554". In the end, Convair emerged as the victor with its design, designated "XF-102", after Lockheed dropped out and Republic built only a mockup. The development of three different designs was too expensive and in November, only Convair was allowed to continue with its Model 8-80. To speed development, it was proposed to equip the prototypes and pre-production aircraft with the less-powerful Westinghouse J40 turbojet. Continued delays to the J67 and MA-1 (formerly "MX-1179") FCS led to the decision to place an interim aircraft with the J40 and a simpler fire control system (dubbed "E-9") into production as the F-102A. The failure of the J40 led to the Pratt & Whitney J57-P-23 turbojet with afterburner, rated with 10,000 pounds-force (44 kN) of thrust being substituted for the prototypes and F-102As. This aircraft was intended to be temporary, pending the development of the F-102B, which would employ the more advanced Wright J67, a licensed derivative of the Bristol-Siddeley Olympus which was still in development. The F-102B would later evolve to become the F-106A, dubbed the "Ultimate Interceptor".

The prototype YF-102 made its first flight on 23 October 1953, at Edwards AFB, but was lost in an accident nine days later. The second aircraft flew on 11 January 1954, confirming a dismal performance. Transonic drag was much higher than expected, and the aircraft was limited to Mach 0.98 (i.e. subsonic), with a ceiling of 48,000 ft (14,630 m), far below the requirements.

Introduction to service

The first operational service of the F-102A was with the 327th Fighter-Interceptor Squadron at George Air Force Base, in April 1956, and eventually a total of 889 F-102As were built, production ending in September 1958. TF-102s and F-102s were used in the 1960s by the Air Defense Command (ADC) at Perrin AFB, Texas to train new F-102 pilots. They also provided platform training on flight characteristics of delta-winged aircraft for pilots who were destined to fly the B-58 Hustler bomber for the Strategic Air Command (SAC).

The F-102's official name, "Delta Dagger", was never used in common parlance, with the aircraft being universally known as the "Deuce." The TF-102 was known as the "Tub" because of its wider fuselage with side-by-side twin seating.

During the time the F-102A was in service, several new wing designs were used to experiment with the application of increased conical camber to the wings. Ultimately, a design was selected that actually increased elevon area, reduced takeoff speed, improved the supersonic L/D ratio and increased the aircraft's ceiling to 56,000 ft (17,069 m). A modification was required to the landing gear doors due to the wing redesign.

The Air Defense Command had F-102 Delta Daggers in service in 1960 and the type continued to serve in large numbers with both Air Force and Air National Guard units well into the 1970s. George W. Bush, later President of the United States, flew the F-102 in the 147th Fighter Interceptor Group based at Ellington AFB in Houston, Texas as part of his Texas Air National Guard service from 1968 to 1972.

Vietnam service

The F-102 served in Vietnam, flying fighter patrols and serving as bomber escorts. A total of 14 aircraft were lost in Vietnam: one to air-to-air combat, several to ground fire and the remainder to accidents.

Initially, F-102 detachments began to be sent to bases in Southeast Asia in 1962 after radar contacts detected by ground radars were thought to possibly be North Vietnamese Il-28 "Beagle" bombers – considered to be a credible threat in that time period. The F-102s were sent to Thailand and other nearby countries to intercept these aircraft if they threatened South Vietnam.

Later on, Boeing B-52 Stratofortress strikes, codenamed "Arc Light", were escorted by F-102s based in the theater. It was during one of these missions that an F-102 was shot down by a North Vietnamese Mikoyan-Gurevich MiG-21 using an AA-2 Atoll heat-seeking missile. The MiGs approached undetected, and one of the F-102s was hit by an air-to-air missile, which did not explode immediately, but remained lodged in the aft end of the aircraft, causing stability problems. As the pilot reported the problem to his wingman, the wingman observed the damaged Delta Dagger explode in midair, killing the pilot. This was the only air-to-air loss for the F-102 during the Vietnam War. The other F-102 pilot fired AIM-4 missiles at the departing MiG-21s, but no hit was recorded.

The F-102 was employed in the air-to-ground role with limited success, although neither the aircraft nor the training for its pilots were designed for that role. The 509th Fighter-Interceptor Squadron's Deuces arrived at Da Nang Air Base, 4 August 1964 from Clark Air Base, Philippines. The interceptor was equipped with 24 2.75 in (70 mm) FFARs in the fuselage bay doors. These could be used to good effect against various types of North Vietnamese targets in daylight. At night it proved less dangerous to use heat-seeking Falcon missiles in conjunction with the F-102's nose-mounted IRST (Infrared Search & Track) on nighttime harassment raids along the Ho Chi Minh trail. Some F-102As were configured to accommodate a single AIM-26 Super Falcon in each side bay in lieu of the two conventional AIM-4 Falcons. Operations with both the F-102A and TF-102A two-seaters (which were used in a Forward Air Control role because its two seats and 2.75 in/70 mm rockets offered good versatility for the mission) continued in Vietnam until 1968 when all F-102s were returned to the United States.

Role Interceptor aircraft
Manufacturer Convair
First flight 24 October 1953
Introduction April 1956
Retired 1979
Primary users United States Air Force
Greece
Turkey
Number built 1000
Unit cost US$1.2 million
Developed from Convair XF-92
Developed into F-106 Delta Dart


General characteristics

  • Crew: 1
  • Length: 68 ft 4 in (20.83 m)
  • Wingspan: 38 ft 1 in (11.61 m)
  • Height: 21 ft 2 in (6.45 m)
  • Wing area: 695 ft (64.57 m)
  • Airfoil: NACA 0004-65 mod root and tip
  • Empty weight: 19,350 lb (8,777 kg)
  • Loaded weight: 24,500 lb (11,100 kg)
  • Max takeoff weight: 31,500 lb (14,300 kg)
  • Powerplant: 1 x Pratt & Whitney J57-P-25 afterburning turbojet
    • Dry thrust: 11,700 lbf (52.0 kN)
    • Thrust with afterburner: 17,200 lbf (76.5 kN)
  • Internal fuel capacity: 1,085 US gal (4,107 l)
  • External fuel capacity: 2x 215 US gal (815 l) drop tanks

Performance

  • Maximum speed: Mach 1.25 (825 mph, 1,304 km/h) at 40,000 ft (12,190 m)
  • Range: 1,350 mi (1,170 nm, 2,175 km)
  • Service ceiling 53,400 ft (16,300 m)
  • Rate of climb: 13,000 ft/min (66 m/s)
  • Wing loading: 35 lb/ft (172 kg/m)
  • Thrust/weight: 0.70

Armament

  • Rockets: 24 x 2.75 in (70 mm) unguided rockets in missile bay doors
  • Missiles:
    • 6 x AIM-4 Falcon air-to-air missiles or
    • 3 x AIM-4 Falcon
    • 1 x AIM-26 Falcon with conventional or nuclear warhead

Avionics

  • MG-10 fire control system

End notes