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The Delta-Winged Deuce: Convair’s First Century Series Supersonic Fighter

The F-102A Delta Dagger Interceptor Was A ‘Round The World Cold-War Warrior

Official US Air Force photograph

Convair’s F-102A Delta Dagger served with distinction as an Air Defense Command (ADC) interceptor with the United States Air Force (USAF) and with the Air National Guard (ANG) for twenty years. Commonly referred to as The Deuce, the F-102A was the first operational delta-winged supersonic jet interceptor to see service with the USAF and ADC. But the design of the F-102, which was drawn to compete in a 1948 USAF competition to place in service a new “ultimate” interceptor and derived from Convair’s XF-92A delta-wing research aircraft, required major revisions before the jet was ready to enter service.

Official US Air Force photograph

Initially the YF-102 prototypes were both underpowered due to engine development snags and slow due to a phenomenon called transonic drag. The engine issues eventually led to the F-102 being powered by the Pratt & Whitney J57 axial-flow turbojet engine with afterburner- the power plant used in such designs as the North American F-100 Super Sabre, the Vought F-8 Crusader, and the Douglas A-3 Skywarrior. After the first YF-102 first flew on October 23rd 1953 the performance of the aircraft was deemed unsatisfactory (read it was a dog) and drove Convair back to the drawing board.

Official US Air Force photograph

Transonic drag occurs as an aircraft approaches supersonic speeds. Without slogging through the physics involved, the phenomenon was causing especially high drag in the forward fuselage around the canopy, at the engine intakes, and along the sides of the fuselage aft of the wing leading edge. The Convair engineers lengthened the fuselage of the aircraft some 11 feet. They also narrowed the canopy and redesigned the engine intakes. But the real difference maker in the revised design was the narrowing of the fuselage aft of the wing leading edge and widening of it forward of the vertical stabilizer- employing something called area rule.

YF-102 (left) and YF-102A (right). Official US Air Force photograph

Now I don’t know if there was a Coke bottle sitting on some engineer’s desk when that “Eureka” moment took place, but we do know that incorporating the Whitcomb Area Rule (AKA the transonic area rule) into the design solved the F-102’s transonic drag problem. The fuselage width was reduced from just aft of the wing leading edge and widened aft ahead of the wing trailing edge. Fairings were added aft of the wing trailing edge and extending well beyond the afterburner on both sides of the jet’s fuselage. Combined these changes resulted in the Deuce’s waspish figure- resembling as much as anything the shape of a Mark 1 Mod Zero Coca-Cola bottle. Aircraft designed to operate in the transonic speed ranges like the Convair B-58 Hustler, Northrop F-5 Freedom Fighter and T-38 Talon and many others have employed the area rule ever since. The redesigned F-102 prototype, dubbed the YF-102A, first flew on December 20th 1954.

Official US Air Force photograph

So now that Convair had a supersonic design and an engine to power it, the company received a contract to produce the Delta Dagger. Other features of the revised F-102A design included primarily aluminum alloy construction with some titanium in the structure. The low-mounted swept delta wing had a leading edge sweep of 60 degrees. Those wings had wing fences mounted inboard and outboard along with two-section hydraulically-actuated elevons at the trailing edge of each wing. The vertical stabilizer was triangular in shape with a hydraulically-actuated trailing edge rudder. The surface area of the vertical stabilizer was increased early in production of the F-102A.

Official US Air Force photograph

The F-102A also employed a pair of hydraulically-actuated airbrakes mounted at the base of the vertical stabilizer. A braking parachute was housed between the airbrake surfaces, meaning it could only be used when the airbrakes were deployed. The revised engine intakes employed splitter plates to reduce drag and turbulence along the fuselage. The Deuce was not armed with any internal guns- it had a ventral weapons bay just aft of the nose gear to carry Hughes GAR-series (AIM-4) Falcon air-to-air missiles. In addition folding-fin aerial rockets (FFARs) could be fired from mounts in the weapons bay doors. Though not designed to carry drop tanks at first, the ability to carry two 230 gallon drop tanks was later added.

Official US Air Force photograph

The F-102A first entered service during April of 1956 with the 327th Fighter Interceptor Squadron (FIS) at George Air Force Base (AFB) at Victorville in California. Of the 889 F-102As built before production ended in September of 1958, the majority were operated first by ADC squadrons, many of which were based in warm sunny locales like Elmendorf AFB in Alaska, Thule Air Base in Greenland, and Keflavik Air Base in Iceland. These cold-soaked but alert Deuces intercepted hundreds of Soviet Tupelov Tu-95 Bears, Tu-16 Badgers, Myasishchev M-4 Bison, and many more during their Cold War service.

Official US Air Force photograph

As the F-102A continued to serve with the ADC and ANG, several revised wing designs were evaluated to research the impact of increased conical camber to the wing shape. The wing design eventually selected had larger elevons and resulted in lower takeoff speeds higher service ceiling of 56,000 feet. The jets were also retrofitted with infrared search and tracking systems IRSTs), radar warning receivers (RWRs), backup artificial horizons, and additional transponders. Fire control systems were incrementally improved as well- a critical need for an aircraft relying solely on missile systems for its offensive firepower. The F-102A also received a runway arrestor hook, strengthened landing gear, and a removable inflight refueling probe used when transiting during overseas deployments.

Official US Air Force photograph

To train F-102A pilots, Convair took the basic airframe and widened the forward fuselage to accommodate two side-by-side seats. The resulting aircraft was the TF-102A. Though contracted to build 111 of them, Convair built a total of 63 of these trainers, somewhat unflatteringly dubbed The Tub. At the time the side-by-side seating arrangement was in vogue with other trainer derivatives like the British Hawker Hunter T.7 and English Electric Lightning T.4- both of which looked a thousand percent better than The Tub. Though the TF-102As were slower than the F-102A they, like the F-102A, saw combat. In Vietnam.

Official US Air Force photograph

Things started slowly. F-102As actually began showing up in Southeast Asia in 1962 to counter what were thought to be North Vietnamese Ilyushin Il-28 Beagle bombers. Deuces were deployed to Thailand and other Southeast Asian places in order to potentially intercept the Beagles should they attack their neighbors to the South. F-102As flew escort missions for Boeing B-52 Stratofortresses flying Arc Light strikes over North Vietnam. An unfortunate F-102A pilot was shot down by a North Vietnamese Mikoyan Mig-21 Fishbed during one of these escort missions. This was the only loss of an F-102A in air-to-air combat during the Vietnam War. Deuces were also used against ground targets. The 509th FIS of the 405th Fighter Interceptor Wing (FIW) moved from Clark AFB in the Philippines to Da Nang during August of 1964. The 64th FIS also deployed to Southeast Asia.

Official US Air Force photograph

Because the F-102A could fire FFARs from the weapons bay doors they were used as daylight ground attack aircraft, albeit with very limited success. They also flew night interdiction missions along the Ho Chi Minh Trail using the IRST sensor to detect targets and the Falcon missiles to attack them- albeit again with limited success. The Air Force even used TF-102As as forward air control (FAC) aircraft for a time, taking advantage of the ability of the Tub to fire FFARs at ground targets. 14 F-102As were lost in Vietnam before the aircraft rotated back to CONUS- the majority of which were the result of operational accidents or sapper attacks on the ground.

Official US Air Force photograph

F-102As served all over the world from bases on American, North Atlantic Treaty Organization (NATO), and South East Asia Treaty Organization (SEATO) allied nations. The McDonnell F-101 Voodoo, the McDonnell Douglas F-4 Phantom II, and Convair’s own derivative of the F-102A, the F-106 Delta Dart steadily replaced F-102As in ADC service. When the F-102A was finally retired from active-duty Air Force service by the 57th FIS after having equipped 25 ADC squadrons and a total of 43 USAF squadrons in 1973, the delta-winged Deuce kept flying with ANG units. But all good aerospace things eventually come to an end. For the F-102A the end occurred during October of 1976 when the 199th FIS Fighting Tikis, Hawaii ANG flew the last operational F-102A sorties.

Official US Air Force photograph

But that wasn’t quite the end for the Deuce. Hundreds of retired F-102As were converted to target drones- many of them under Project Pave Deuce as a part of the Full Scale Aerial Drone (FSAT) program. Designated as QF-102A, PQM-102A, and PQM-102B, these sacrificial jets were used to validate the weapons systems used on the next generations of fighter/interceptor aircraft and weapons systems such as the McDonnell Douglas F-15 Eagle and the Patriot surface-to-air missile system. The last of the F-102A drones was expended in 1986.

Official US Air Force photograph

NATO allies Turkey and Greece also operated the F-102A and TF-102A. Ironically the Turkish Air Force (Türk Hava Kuvvetleri) F-102As saw combat missions against the Hellenic Air Force (Polemikí Aeroporía) during the 1974 Turkish invasion of Cyprus although not against HAF F-102As. Rather, HAF Northrop F-5 Freedom Fighters mixed it up with the Turkish Deuces. Claims of aerial victories during these engagements are largely unsubstantiated, but neither country admits to losses of their aircraft. In any case the last operational F-102As in the world were retired in 1979 by the Turks.

Official US Air Force photograph

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Bill Walton

Written by Bill Walton

Bill Walton is a life-long aviation enthusiast and expert in aircraft recognition. As a teenager Bill helped his engineer father build an award-winning T-18 homebuilt airplane in their Wisconsin basement. Bill is a freelance writer, an avid sailor, engineer, announcer, husband, father, uncle, mentor, coach, and Navy veteran. Bill lives north of Houston TX with his wife and son under the approach path to KDWH runway 17R, which means they get to look up at a lot of airplanes. A very good thing.

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