Convair F-102 Delta Dagger
The Convair F-102 Delta Dagger was a US interceptor aircraft built as part of the backbone of the United States Air Force's (USAF) air defenses in the late 1950s. Entering service in 1956, its main purpose was to intercept invading Soviet bomber fleets. Designed and manufactured by Convair, 1,000 F-102s have been built.
A member of the Century Series, the F-102 was the first operational supersonic interceptor and delta-wing fighter of the USAF. 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 types such as the Northrop F-89 Scorpion, and by the 1960s, it saw limited service in Vietnam 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 to United States Air National Guard duty by the mid-to-late 1960s, and the type was 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.
Design and development
Initial designs and problems
On 8 October 1948, the board of seniors 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 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), which would first be designed, before moving on to the airframe to ensure compatibility with the FCS. The airframe and FCS together is called the weapon system.
The YF-102 with its straight sided fuselage.
In January 1950, the USAF Air Materiel Command issued request for proposals (RFP) to 50 companies for the FCS, of which 18 responded. By May, the list was revised downwards to 10. Meanwhile, the a board at the US 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 revised down 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 was issued on 18 June 1950, and in January 1951, six manufacturers responded. On 2 July 1954, three companies, Convair, Republic and Lockheed won the rights build a mock-up. Up until then, Convair had done research into delta-winged aircraft, experimenting with different designs, two of which fall under the name P-92. Out of the three, the best design would 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 only building a mock-up. 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, 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 24 October 1953, but was lost to 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.
To solve the problem and save the F-102, Convair embarked on a major redesign, incorporating the recently discovered area rule, while at the same time simplifying production and maintenance. The redesign entailed lengthening the fuselage by 11 ft (3.35 m) and "pinched" at the mid section (dubbed the "Coke Bottle configuration"), with two large fairings on either side of the engine nozzle, with revised intakes and a new, narrower canopy. A more powerful model of J57 was fitted, and the aircraft structure was lightened.
The first revised aircraft, designated YF-102A flew on 20 December 1954, 118 days after the redesign started, exceeding Mach 1 the next day. The revised design demonstrated a speed of Mach 1.22 and a ceiling of 53,000 ft (16,154 m), which was sufficient for the Air Force to allow production of the F-102.
The production F-102A had the Hughes MG-3 fire control system, later upgraded in service to the MG-10. It had a three-segment internal weapons bay under the fuselage for air-to-air missiles. Initial armament was three pairs of GAR-1/2/3/4 (Later re-designated as AIM-4) Falcon missiles, which included both infrared and semi-active radar homing variants. The doors of the two forward bays each had tubes for 12 FFAR rockets (for a total of 24) with initially 2 in (5.1 cm) being fitted and later 2.75 in (70 mm) replacing them. The F-102 was later upgraded to allow the carriage of up to two GAR-11/AIM-26 Nuclear Falcon missiles in the center bay. The larger size of this weapon required redesigned center bay doors with no rocket tubes. Plans were considered to fit the MB-1 Genie nuclear rocket to the design, but although a Genie was test fired from a YF-102A in May 1956, it was never adopted.
Because of the changes that had to be made in redesigning the aircraft with the area rule in mind, the ambitious plan to manufacture the production aircraft on the prototype tooling had to be abandoned; two-thirds of the 60,000+ pieces of tooling had to be scrapped or heavily modified.
The F-102 received several major modifications during its operational lifetime, with most airframes being retrofitted with infrared search/tracking systems, radar warning receivers, transponders, backup artificial horizons, and improvements to the fire-control system. A proposed close-support version (never built) would have incorporated, in addition, an internal Gatling gun, an extra two hardpoints for bombs (in addition to the two underwing pylons for drop tanks that were fitted to all production F-102s), bigger internal fuel tanks, and an in-flight-refueling probe.
To train F-102A pilots, the TF-102A trainer was developed, with 111 eventually manufactured. The aircraft was fitted with a side-by-side cockpit to facilitate ease of pilot training. This required a redesign of the cockpit and nose incorporating a set of vortex generators on the top of the cockpit to prevent flow separation under certain circumstances, and repositioning of the intake ducts. Despite the many changes, the aircraft was combat-capable, although this variant was predictably slower, only reaching subsonic speeds in level flight.[
The F-102's intended successor was the improved F-102B "Ultimate Interceptor". The design, which had the originally intended J67 engine replaced by a Pratt & Whitney J75 underwent so many aerodynamic changes including a variable-geometry inlet design that it essentially became an entirely new aircraft and hence was redesignated as the F-106. Convair would also use a delta wing in the Mach 2 class B-58 Hustler bomber.
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 ADC (Air Defense Command) 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 bomber.
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 wide fuselage.
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 USAF 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, TX 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 15 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, when radar contacts that were detected by ground radars were thought to possibly be North Vietnamese Il-28 "Beagle" bombers, which was considered a very credible threat during that time period. F-102s were sent to Thailand and other nearby countries to intercept these aircraft if they threatened South Vietnam at any time.
F-102As of the 509th FIS over Vietnam, November 1966. These aircraft wear standard Southeast Asia camouflage (T.O. 1-1-4).
Later on, B-52 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 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 his mechanical problem to his wingman, the wingman observed the damaged Delta Dagger explode in midair, killing the pilot. The other F-102 pilot was able to fire AIM-4 missiles at the fleeing MiG-21s, but no hits were recorded. This was the only air-to-air loss for the F-102 during the Vietnam War.
The F-102 was tried with limited success for several years in the air-to-ground role, although neither the aircraft nor training were designed for the role. The 509th Fighter-Interceptor Squadron's Duces 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 was 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.
Operations with both the F-102A and TF-102A two-seater (which was used in a Forward Air Control role because its two seats and 2.75 in/70 mm rockets offered good versatility for the mission) in Vietnam until 1968 when all F-102 aircraft were sent back to the United States.
 Later use
In 1973, six aircraft were converted to target drones as QF-102A and later PQM-102 series, simulating MiG-21s, under project Pave Deuce.  This began a program where hundreds of F-102s were converted for use as target drones for F-4 and F-106 aircraft as well as later F-15 aircraft and testing of the US Army's Patriot missile system. 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.
The F-102 and TF-102 were exported overseas to both Turkey and Greece. The Turkish F-102s saw combat missions during the 1974 Turkish invasion of Cyprus. There have been claims of air combat between Greek F-5s and Turkish F-102s above the Aegean Sea during the Turkish invasion. A Greek internet website editor, Demetrius Stergiou, claims that the Greek F-5s had shot down two Turkish F-102s, while the Turkish side has claimed that their F-102s had shot down two Greek F-5s; however, both Greece and Turkey have officially denied any losses. Three days after the Turkish invasion began, the Greek military junta in Athens collapsed on 23 July 1974. The F-102 was finally retired from both of those air forces in 1979.
The F-102 left US service in 1976, while the last PQM-102 drone was expended in 1986. No F-102s remain in flyable condition today although many can be seen at museums.
Carolinas Aviation Museum's South Carolina Air National Guard F-102 being washed by US Airways employees. This aircraft came from McEntire Air Guard Base in SC.
Prototypes. Non area-ruled fuselage. Powered by 14,500 lbf (64.5 kN) J57-P-11, two built.
Area-ruled prototypes. 16,000 lbf (71.2 kN) J57-P-23. Four converted from pre-production aircraft.
Production Model. Initial eight pre-production aircraft built with non-area ruled fuselage. Remainder (879) with area ruled fuselage.
Two-seat training version, 111 built.
The original designation of the F-106A.
Proposed tactical attack version with J57-P-47 engine. Two converted As as YF-102C engineering test beds.
Target drones converted from the F-102A. Six built.
Unpiloted target drones. 65 converted.
Revised target drone conversion, capable of being flown remotely or by pilot in cockpit. 146 converted.
Carolinas Aviation Museum's South Carolina Air National Guard F-102 being washed by US Airways employees.
Hellenic Air Force
Turkish Air Force
United States Air Force
Below is a partial list of museums or locations with an F-102 Delta Dagger on display:
F-102A, 61-266, On in static display at Stephenville, Newfoundland. This aircraft was formerly of the US 59th Fighter Interceptor Squadron, Goose Bay (Happy Valley), Labrador.
TF-102A, 55-4035, on display at Dekelia-Tatoi
F-102A, 56-1001, on display at Tanagra
F-102A, 56-1040, on display at Tanagra
F-102A, 56-1106, on display at Tanagra
F-102A, 56-1232, on display at Larisa
TF-102A, 56-2355, on display at Dekelia-Tatoi
F-102A, 61-032, static display at Royal Netherlands Military Aviation Museum, Soesterberg Air Base 
F-102A, 56-1052, on display at Royal Netherlands Military Aviation Museum.
Turkish Air Force
F-102A, 55-3386, on display at the Turkish Air Force Aviation Museum, Yesilkoy, Istanbul
TF-102A, 56-2368, on display at the Turkish Air Force Aviation Museum, Etimesgut, Ankara
United States
YF-102A, 53-1787, on the Air Park at Jackson Barracks Military Museum, New Orleans, Louisiana.
YF-102A, 53-1788, Carolinas Aviation Museum, Charlotte, NC formerly on display at Florence, South Carolina.
TF-102A, 54-1353, on the Century Circle at Edwards Air Force Base, near Rosamond, California, formerly on display at General William J. Fox Airfield in Lancaster, California.
TF-102A, 54-1366, on display at the Pima Air and Space Museum adjacent to Davis-Monthan AFB in Tucson, Arizona.
F-102A, 54-1405, Strategic Air and Space Museum, Ashland, Nebraska near Offutt AFB, Nebraska.
F-102A in the Cold War Gallery of the National Museum of the United States Air Force
F-102A, 56-00984, at Wings Over the Rockies Museum. (former Lowry AFB) Denver, Colorado.
F-102A, 56-00985, on display at McEntire Air National Guard Base, South Carolina
F-102A, 56-00986, at MAPS Air Museum, Akron-Canton Regional Airport, Ohio.
F-102A, 56-1053, (painted as 56-1274) at Elmendorf AFB, Alaska Heritage Park.
F-102A, 56-1109, at Peterson Air and Space Museum, Peterson AFB, Colorado Springs, Colorado.
F-102A, 56-1365, at Empire State Aerosciences Museum, Glenville, New York.
F-102A, 56-1368, tail number 0-61368 at Evergreen Aviation Museum, McMinnville, Oregon.
F-102A, 56-1413, at Castle Air Museum (former Castle AFB), Atwater, California,
F-102A, 56-1416, at National Museum of the United States Air Force, Wright-Patterson Air Force Base near Dayton, Ohio.
F-102A, 56-1476, at Minnesota Air National Guard Base, Minneapolis, Minnesota.
TF-102A, 56-2317, at Grissom Air Museum, Grissom Air Reserve Base, Peru, Indiana.
TF-102A, 56-2346, at Fort Indiantown Gap, Pennsylvania.
TF-102A, 56-2352, at Air Force Heritage Park, Lackland AFB, San Antonio, Texas'
F-102A, 56-1515, at McChord Air Museum, McChord Air Force Base, Washington.
F-102A, 57-0858, at Tyndall Air Park, Tyndall AFB, Florida.
F-102A, 56-1105, on static display at the Lions park in Great Falls, Montana.
F-102A, Unknown, on static display at the entrance to Jacksonville Air National Guard Base, Florida
F-102A, 53-1804, on static display at Fresno ANG base, Fresno, California.
TF-102A, 56-2346, on display at Pennsylvania National Guard Military Museum, Pennsylvania National Guard Headquarters, Fort Indiantown Gap, Pennsylvania. (Aircraft was assigned to the Pennsylvania Air National Guard, at the 112th Fighter Interceptor Group, Pittsburgh International Airport, Coraopolis, Pennsylvania from 1960–1974 and is on loan from the National Museum of the United States Air Force).
 Specifications (F-102A)
Orthographically projected diagram of the F-102A Delta Dagger.
Data from The Great Book of Fighters
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: 661.5ft²/61.52m² (Original Wing) or 695 ft²/64.57m² (Conically-Cambered Wing) ()
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 × 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: 2 × 215 US gal (815 l) drop tanks
Maximum speed: Mach 1.25 (825 mph, 1,304 km/h) at 40,000 ft (12,190 m)
Range: 1,350 mi (1,170 nmo, 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/ft² (172 kg/m²)
Rockets: 24 × 2.75 in (70 mm) FFAR (Folding Fin Aerial Rocket) unguided rockets in missile bay doors
6 × AIM-4 Falcon air-to-air missiles or
3 × AIM-4 Falcon
1 × AIM-26 Falcon with conventional or nuclear warhead
MG-10 fire control system