F-102 Delta Dagger
From Wikipedia:
"The Convair F-102 Delta Dagger was an US interceptor aircraft 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 bomber fleets.
The aircraft's development was long and troubled, and, by the early 1960s, it was being supplemented by F-101 Voodoos, replaced by F-106 Delta Darts, and, later, by 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.
Design and development
The F-102 was developed from the XF-92A delta wing research aircraft of the late 1940s. The Air Force took a new approach in putting out the request for proposals for an operational interceptor, considering both the aircraft and armament together in what became known as a "weapon system". While the contract for the complex fire-control system for the new fighter was awarded to Hughes Aircraft, for its MA-1 system, a Request for proposal for Project MX-1554 for the airframe was issued on 18 June 1950, and in January 1951, six manufacturers responded, of which Convair, Lockheed, and Republic were chosen to proceed with design. 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, while the definitive production version, referred to as the "Ultimate Interceptor" would be powered by the Wright J67, a licensed derivative of the Bristol-Siddeley Olympus which was still in development.Continued delays to the J67 and the MA-1 fire control system led to the decision to place an interim aircraft with the J40 and a simpler fire control system into production as the F-102A "Interim Fighter", while the version with the final engine and fire control system became the F-102B. The failure of the J40 led to the Pratt & Whitney J57 being substituted for the prototypes and F-102As.
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 (14,600 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 (16,150 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 Falcon missiles, a mix of infrared and semi-active radar homing. The doors of the two forward bays each had tubes for 12 x 2.75 in FFAR rockets (for a total of 24). The F-102 was later upgraded to allow the carriage of a GAR-11 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 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.
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 Fighter". 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 F-106 Delta Dart.
Operational history
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 were built. 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. A modification was required to the gears 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 as part of his Air National Guard service in the late 1960s and early 1970s
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 ft² (64.57 m²)
- 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: 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/ft² (172 kg/m²)
- Thrust/weight: 0.70
Armament
- Rockets: 24× 2.75 in (70 mm) unguided rockets in missile bay doors
- Missiles:
- 6× AIM-4 Falcon air-to-air missles or
- 3× AIM-4 Falcon
- 1× AIM-26 Falcon with conventional or nuclear warhead
Avionics
- MG-10 fire control system"