About this Product
World War II saw the development of the heavy bomber as a decisive weapon which, in sufficient numbers, could overcome defensive fighters and guns and lay waste to strategic targets. The addition of nuclear weapons to the bomber's armament made it even more formidable, and by the late 1940s, US planners saw the growth of a Soviet nuclear-armed bomber fleet as a terrifying threat to North American security. Conventional subsonic fighters with guns and free-flight air-to-air rockets would be incapable of reaching these incoming bombers in time to prevent even one from delivering a devastating nuclear attack. As a result, supersonic speed, long-range guided missiles and precise radar-based control of an interception became prerequisites for a new breed of fighters, beginning with the F-102.
A massive research and development effort produced the F-102A ‘1954 Fighter', the J57 afterburning turbojet, its Hughes MX-1554 fire control system and, in due course, the Semi-Active Ground Environment (SAGE) radar and communications network that covered North America to guide its airborne defences. In service, F-102As also provided air defence in Europe with USAFE, in the Far East and in Southeast Asia, where they protected US airbases in South Vietnam and Thailand from air attack by North Vietnamese fighters and bombers and escorted B-52s and fighter-bombers on their attack sorties.
This illustrated study from leading expert Peter E. Davis details the design, development, and deployment of the futuristic F-102, including its complex research program and role in Vietnam.
A New Shape
Nazi Germany's frantic attempts to defeat the armada of Allied bombers that was systematically destroying its war effort in 1944 led to a wealth of highly innovative aircraft and missile concepts which continues to influence the world's design teams 75 years later. Among the research materials recovered by Allied forces was a range of designs using the delta wing originated by Alexander Lippisch. Although other German designers such as the Horten brothers, and Boris Cheranovsky in Russia, had previously built tail-less aircraft, Lippisch was the pioneer of the delta wing with the original idea of using its potentially large internal space to build massive cargo-carrying aircraft. His work led to the tail-less, swept-wing Me 163 Komet rocket-powered interceptor but his first true delta design was the P13a interceptor, for which he had built a glider test model, the DM-1, by the war's end. Transferred together with Lippisch to the USA in 1946, the DM-1 was wind-tunnel tested, and the Consolidated Vultee Aircraft Corporation (Convair) of San Diego took a particular interest in the highly innovative design. Its XF-92A jet-powered research aircraft, originated by Chief of Design Adolph Burstein in response to a June 1946 USAAF request for an experimental point-defence interceptor, bore many resemblances to the Lippisch glider and had his tacit approval. Although it did not progress to a production standard the XF-92A generated valuable research data and proved to be popular with test pilots like Chuck Yeager. Crucially, it showed that the delta-wing concept could work well in reducing drag and simplifying flying control processes.
Impressed by the XF-92A, the USAF included the design for a developed version of the little delta in the competition for its 1949 Weapon System 201A interceptor project, leading to the world's first supersonic interceptor. The project's title implied a new philosophy in procurement of sophisticated new weapons that covered every aspect of the purchase, from the airframe, engine and armament to the training manuals, servicing equipment and training - a policy which became known as the Cook-Craigie Plan. It pre-supposed that, instead of the usual prototypes and testing, an aircraft could be ordered straight into production, and any modifications could be incorporated in the light of flight-testing of the first batch. Although this plan became an industry standard, the MX-1154, or F-102 (the developed XF-92A), would require major alterations even after it had entered service. Initially, the basic XF-92 was enlarged by 25 per cent and doubled in weight to contain the larger J57 engine, the Hughes Falcon guided missiles and their associated MX-1179 (MG-10) fire-control system (guns were never considered necessary), together with enough fuel for supersonic interceptions over a 375-mile combat radius. While the complex network of suppliers, managed overall by Convair, was being established, the first YF-102 was constructed and test-flown on 24 October 1953. It encountered severe difficulties in flight and crash-landed a few days later. With 42 production aircraft nearing completion, it became clear from tests with the second YF-102 that the fighter was incapable of supersonic flight.
Sharpening the Dagger
Urgent re-work of the airframe was clearly required to cure violent instability in the transonic speed range. A modified ‘Case X' wing increased its stable speed to Mach 0.997, but the intended maximum speed of Mach 1.5 was still quite impossible by March 1954 as the first ‘production' aircraft emerged from the factory and cancellation loomed. In that year, radar-equipped F-86D Sabres were achieving higher speeds in squadron service. By happy coincidence NACA's Langley Laboratory had developed a transonic wind-tunnel (absent during the F-102's gestation) and aerodynamicist Richard Whitcomb used it to evolve a ‘coke bottle' fuselage and wing combination that spread an aircraft's drag pattern smoothly across its surface. His ‘Area Rule' principle was applied to several designs, including the F-102, resulting in a longer fuselage, increased in area at each end. Equipped with an uprated J57, the ‘wasp-waisted' Model 8-90 (YF-102A) emerged in record time and reached Mach 1.2 on its first test flight on 21 December 1954. Later changes included an enlarged tail-fin and revised intakes, enabling a top speed of Mach 1.5 by January 1956. The modifications were applied to the production line and retroactively to most of the previous examples, including those that had been delivered to the USAF from June 1955. However, almost $20m was wasted in discarded production tools alone. F-102As entered frontline squadron service with the 327th Fighter Interceptor Squadron (FIS) in June 1956 at George AFB, California, and 25 Air Defense Command (ADC) units were Delta Dagger-equipped by the end of 1958. By then around 500 aircraft were being recycled at Convair's Palmdale plant to receive the full MG-10 fire control system.
Caging the Bear
Working with North America's SAGE organisation (or the similar ‘Nadge' system in Europe) required F-102A pilots to adapt to a very different method of interception that meant they had to live for set periods of time in accommodation attached to Zulu alert hangars at bases in the USA, West Germany, Holland or the Far East. When an alarm sounded they slid down fireman's poles into one of four alert cells, where an F-102A was primed ready for take-off. Three minutes later, a pair of jets would be climbing to interception altitude, either with their autopilots linked directly to commands from ground control or with manual control in response to voice commands. With his eyes focused within a sunlight-excluding hood over his radar screen, a pilot would scan for his target as the controller guided him into position. Radar-controlled or infra-red seeking Falcon missiles would then be fired from trapeze launch-rails extending below the fuselage, homing onto targets at a range of around 30,000 ft and a ceiling of 60,000 ft if Soviet bombers or other intruders entered protected air space. To assist with training, 111 TF-102As with side-by-side seating were ordered in 1955. The two-seat ‘Tub' model was fully combat capable and would fly missions during the Vietnam war. More than 1000 F-102s were built, and one unit, the 317th FIS in Alaska, had 46 aircraft on strength and frequently intercepted Soviet Tu-95 ‘Bears' and other bombers. By 1962 the Delta Dagger had become the USAF's principal interceptor, with the 57th FIS at Keflavik AFB, Iceland, being the final squadron equipped with the type.
As later fighters like the F-106A (the ‘Ultimate Interceptor' to replace the F-102 ‘1954 Interceptor') and F-101B Voodoo entered ADC service in 1960, some F-102As were reassigned to Air National Guard (ANG) units. By 1969, 374 of the ANG's 414 interceptors were F-102s, equipping 23 squadrons with colourfully-marked fighters. Like their ADC counterparts, these units competed in annual William Tell weapons meets and, in the case of the Hawaii ANG, flew the F-102 for 17 years. The type's lack of aerial refuelling capability limited its foreign deployments to slow transits by sea, although 87 examples were temporarily equipped with jury-rigged refuelling probes for a Far-East deployment. Pacific Air Forces units flew F-102s, beginning with the 16th FIS at Naha, Okinawa, and the 509th FIS at Clark AFB, inthe Philippines, began to detach aircraft to Don Muang, Thailand, for air defence duties in 1961. Others went to Tan Son Nhut AB, South Vietnam, in response to the threat posed by North Vietnamese Il-28 bombers. Six more were detached to Da Nang AB after the Gulf of Tonkin Incident on 90-day ‘Candy Machine' deployments that included flying top cover sorties for 6252nd TFW attack missions. F-102 pilots in-theatre performed Project Stove Pipe missions in which they used their infra-red detectors to fire missiles at ground targets and provide close-support for friendly troops by firing free-flight rocket pods. Based at Da Nang and Bien Hoa AB in 1966, camouflaged F-102As briefly flew escort for B-52 Arc Light missions over North Vietnam until one F-102A was shot down by a MiG-21. Fourteen others were lost to ground fire or operational accidents, but their presence as air defence cover may well have deterred North Vietnamese air attacks on US bases in 1965-66.
Greece and Turkey obtained ex-ANG F-102s as NATO members under the Military Assistance Programme from 1968 following their re-work by Fairchild Industries and Ling Temco Vought. By 1969 Turkey had two squadrons and Greece operated 20 F-102As and four TF-102As within its 114 Wing at Tanagra. Both countries used them until 1978-79, and two Turkish examples scored the type's only operational air-to-air kills when they shot down two Greek Northrop F-5As in 1974 during a dispute over Cyprus, causing a US arms embargo on their country. A far greater number of Delta Daggers from the 400 stored in 1972 spent their final years as full-scale targets for air-to-air missile testing and armament practice in the USA. Converted to piloted QF-102A or unmanned drone PQM-102A configuration by Sperry Rand Corporation in the Pave Deuce programme, 215 aircraft were flown from White Sands Missile Range or Tyndall AFB as targets for the pilots of a later generation of fighters. They could accurately simulate MiG-23s, Su-19s or MiG-25s flying at sub-Mach 3 speeds. Some lasted for one sortie, others for up to twenty. One example survived 48 hits by missiles before succumbing, QF-102s revealing weaknesses in the capability of US missiles.
1. F-102 Units (USAF, ANG and foreign)
2. F-102 statistics
3. Colour Plates commentaries