<p>The F-102 was the first of Convair's great delta twins. Its radical shape was unique in USAF service, while its speed and powerful weapons capability made it the backbone of Air Defense Command. Its high-profile front-line days were relatively short-lived, but the 'Deuce' had a long career which took it to Vietnam and beyond.
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<p>Like that of many radical designs, development of the F-102 Delta Dagger was somewhat protracted, the type being plagued by aerodynamic and other problems which, for a time, looked as if they might be beyond resolution. Ultimately, though, the 'Deuce', as the F-102 became known, matured into a fine interceptor and one which enjoyed a lengthy operational career.
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<p>The origins of the F-102 project can be traced back to January 1949 when an ADO (Advanced Development Objective) calling for a new fighter capable of exceeding the performance of Soviet jet bombers was issued. Most commonly known as the '1954 interceptor' (a reference to the anticipated in-service date), the ADO very quickly crystallized into a firm project, a formal RFP (Request For Proposals) being issued to industry in June 1950. Essentially, the airframe of the new weapons system was known as Project MX-1554, the more or less concurrent development of the Project MX-1179 ECS (Electronic Control System) around which it would be built culminating in the award of a contract to the Hughes Aircraft Company in October 1950.
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<p>Industry response to the MX-1554 portion of the package was good, no fewer than nine proposals having been submitted by six manufacturers when bidding closed at the beginning of 1951. Top of the list with three submissions was Republic, while North American came up with two different proposals, single offerings being contributed by Chance Vought, Convair, Douglas and Lockheed. During the first six months of 1951 the USAF studied the various submissions closely before, on 2 July, announcing that Convair, Lockheed and Republic had all been invited to proceed with development up to and including the mock-up inspection stage, at which time the most promising proposal would be rewarded with a firm production contract.
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<p>Subsequently, however, this line of attack was very quickly abandoned, Lockheed's submission being dropped shortly afterwards. Republic's XF-103 was allowed to proceed, although this eventually fell victim to budgetary reductions when further work on the sole surviving prototype was cancelled in September 1957. Thus, the letter contract of 11 September 1951 effectively meant that Convair's submission, based on the earlier XF-92A delta research aircraft, had won MX-1554 and would initially proceed with the WestinghouseJ40 engine pending the availability of the more powerful Wright J67 which had been earmarked for the new interceptor.
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<p>Fairly soon afterwards, in November 1951, the USAF elected to implement the 'Cook-Craigie Plan' in an attempt to accelerate the project, this calling for early tooling and limited initial production, and for the eradication of faults by intensive test flying and much accelerated production thereafter. Unfortunately, in practice, it proved to be not quite so simple.
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<p>The early development period was in fact one of almost continuous change, early evidence of this coming in December 1951 when the USAF awarded Convair a new letter contract calling for production of an interim version of the MX-1554 interceptor. This acknowledged that the planned J67 engine would not be ready in time. Subsequently, redesigned taller vertical tail surfaces were introduced with effect from the 66th production F-102A, these overcoming the instability which was still giving cause for concern when flying at high speed. The revised tail surfaces were retrospectively fitted to most of the surviving early aircraft.
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<p>Although this period undoubtedly represented the nadir of Convair's hopes for its new fighter, there were one or two bright spots to relieve the gloom which must have prevailed at San Diego, where the Delta Dagger was manufactured. With the redesign work well in hand, the USAF showed faith in Convair's ability to resolve the difficulties by placing a contract for 37 more F-102As during March 1954. This was followed in June of the same year by a further order for 108 aircraft, although the latter batch was later placed 'on hold' pending the outcome of trials with the redesigned 'Deuce'.
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<hi style=hdr1>Performance as Advertised</hi>
<p>Trials got under way on 19 December 1954 when a modified aircraft, the first of four pre-production YF-102As, took to the air. This aircraft very quickly provided proof that the various 'fixes' had indeed achieved the desired objective, the machine exceeding Mach 1 on its second flight and eventually attaining Mach 1.22 and 53,000 ft (16,155 m), both being very close to the required performance levels. From this point onwards, the Delta Dagger project began to make very real progress, flight testing of this and other modified aircraft occupying much of 1955; one notable highlight occurred in July when a YF-102A launched six Falcon air-to-air missiles and 24 unguided rockets in less than 10 seconds. Just two weeks earlier, on 24 June, the first full production example of the F-102A made a successful maiden flight and little time was wasted in handing this over to the USAF five days later, on 29 June.
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<p>Following all the trials and tribulations of the past few years, Convair executives must have breathed a collective sigh of relief in April 1956 when the Delta Dagger finally entered service with Air Defense Command's 327th Fighter-Interceptor Squadron at George AFB, California, in the process becoming the first of three delta-winged aircraft to operate with the USAF. Nevertheless, it was almost three years later than first envisaged and, although now in service, the F-102 was still by no means out of the wood as far as the parent company was concerned, being troubled by a number of 'bugs' during its early operational career. Many of these related to the fire-control system, and the initial service period was one of progressive updating. One example of this process was the substitution of the MG-10 FCS in place of the original MG-3, while datalink facilities were also provided. With regard to the basic airframe, a new wing was evaluated in prototype form from May 1957 onwards, this being installed on new production aircraft with effect from October of that year and progressively retrofitted to earlier examples as these came up for overhaul. With this wing the F-102A was capable of reaching 55,000 ft (16,765 m) and also had much improved stability, especially at low speeds.
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<hi style=hdr1>Rapid Service Entry</hi>
<p>Once the type finally entered service, little time was wasted in building up the force, five squadrons either being fully equipped or in the process of transition at the end of 1956. The succeeding year was, however, little short of remarkable, with 14 additional squadrons taking delivery of the 'Deuce' during 1957. The peak Air Defense Command strength of 26 squadrons was reached during 1958, although this total was in fact maintained only briefly. No less startling was the subsequent decline in strength, which provided clear evidence that the F-102 was viewed largely as an interim type by ADC; however, the type did continue in front-line service with elements of USAFE (United States Air Forces in Europe), AAC (Alaskan Air Command) and PACAF (Pacific Air Forces) for some considerable time, as well as providing the backbone of Air National Guard interceptor forces for much of the 1960s and early 1970s. As far as ADC was concerned, though, no fewer than 19 squadrons either re-equipped or disbanded between May 1959 and October 1960, leaving a handful of squadrons on this type until the mid-1960s when, with one exception, they were either deactivated or transferred to PACAF. The sole exception was the 57th FIS at Keflavik, Iceland, which continued to fly the F-102A until April 1973 when it converted to the McDonnell Douglas F-4C Phantom, ending ADC's association with the Delta Dagger after almost 18 years.
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<p>The type remained in front-line operational use with the air arms of Greece and Turkey for a few more years, these forces having taken delivery of a number of surplus USAF single- and two-seat Delta Daggers during the early 1970s.
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<p>In addition to production of 14 prototype and pre-production test specimens and 875 examples of the definitive F-102A, Convair also manufactured a two-seat combat proficiency trainer version under the designation TF-102A. Possessing inferior capabilities to those of the standard F-102A, this originated from an April 1952 requirement for a dual-control version to be used in the transition training of those pilots destined to operate the type. Production authorization came in mid-September of the following year, but this variant also fell victim to the many problems which troubled the whole program at this time, procurement being delayed while Convair struggled to rectify the aerodynamic shortcomings.
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<p>Subsequently, in July 1954, an initial contract was placed for 20 aircraft, inspection of the side-by-side seating arrangement in mock-up form having taken place in January. Apart from the redesigned nose section, the TF-102A was identical to the F-102A and retained the single-seater's weapons capability, although performance was restricted to well below Mach 1 by the enlarged nose and subsonic inlets.
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<p>The TF-102A was flown for the first time on 8 November 1955, early testing revealing a number of failings, not least of which was serious buffeting at high speed. Testing of a revised canopy failed to eradicate the problem, which was eventually overcome by adding vortex generators and increasing the size of the vertical tail. Eventually, procurement of the TF-102A version totalled 111, less than first proposed, with two or three examples of this derivative usually serving with each F-102A squadron.
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<hi style=hdr1>Drop the Pilot</hi>
<p>Although the 'Deuce' came to the end of its front-line operational career with the USAF in the early 1970s, it continued to soldier on in substantial numbers with elements of the ANG for several more years, while another derivative provided sterling service in the training of the dwindling number of aircrews dedicated to the air defense of the USA and in the development of new weapons. This was the PQM-102 pilotless target drone, close to 200 redundant F-102As being converted to this configuration by Sperry Rand during the 1970s. Serving with the Air Defense Weapons Center at Tyndall AFB, Florida, and with the 658th Test Wing at Holloman AFB, New Mexico, drones of this type performed valuable work for several years before the last was destroyed over the Gulf of Mexico in 1983.
<item><hi format=bold>Powerplant:</hi> one Pratt & Whitney J57-P-23 turbojet rated at 11,700 lb (52 kN) dry and 17,200 lb (77 kN) afterburning thrust
<item><hi format=bold>Performance:</hi> maximum speed, clean at 40,000 ft (12,190 m) 825 mph (1,328 km/h); normal cruise speed at 35,000 ft (10,670 m) 540 mph (869 km/h); initial climb rate 17,400 ft (5,304 m) per minute; service ceiling 54,000 ft (16,460 m); tactical radius with two 230-US gal (871-liter) drop tanks and full armament 500 miles (805 km) at 540 mph (869 km/h); maximum range 1,350 miles (2,173 km)
<item><hi format=bold>Weights:</hi> normal loaded, clean 27,700 Ib (12,565 kg); normal loaded, point interceptor 28,150 Ib (12,769 kg); maximum take-off 31,500 lb (14,288 kg)
<item><hi format=bold>Dimensions:</hi> span 38 ft 1.5 in (11.62 m); length 68 ft 4.6 in (20.84 m); height 21 ft 2.5 in (6.46 m); wing area 661.5 sq ft (61.45 m<su>2</su>)
<item><hi format=bold>Armament:</hi> three AIM-4C Falcon infra-red homing air-to-air missiles and one AIM-26A Nuclear Falcon, or three AIM-4A/4E beam-riding and three AIM-4C/4F infra-red homing air-to-air missiles; up to 24 unguided 70-mm (2.75-in) folding-fin aerial rockets were originally carried but these were eventually deleted
