Convair F-102 Delta Dagger
Design & 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". The RFP for Project MX-1554 went out 18 June 1950, and in January 1951 six manufacturers responded, of which Convair, Lockheed, and Republic were chosen to proceed with design. Three of these projects were too expensive, and in November, only Convair was allowed to continue with its Model 8-80, an interim project using the less-powerful Westinghouse J40 turbojet in lieu of the Wright J67 which was still in development.

The 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: Approximately 812 mph, while supersonic, it was far below the requirements. The problem was solved by the use of the area rule, which entailed narrowing the aircraft down in the mid-section, moving the cockpit and intakes back further, blending the outer contours of the intake duct, lengthening the nose and adding two fairings on either side of the engine nozzle, resulting in the new "'YF-102A design'". The new design was more than twice as fast as the non-area ruled design. The "'YF-102A'", however was not exactly the same as the production F-102A design in that its nose was considerably longer than the "'F-102A.'"

Somewhere along the way, the Wright J-67 was cancelled, and the J-40 was replaced with a Pratt & Whitney J-57.

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 produce 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 direct successor was the related F-106 Delta Dart, which was originally designated YF-102B. The design underwent so many aerodynamic changes including a larger J-75 turbojet and a variable-geometry inlet design that it essentially became an entirely new plane.

Wikipedia: F-102 Delta Dagger