McDonnell F-101 Voodoo
Design and Development

Initial design on what would eventually become the Voodoo began just after World War II in response to a USAAF Penetration Fighter Competition in 1946 for a long-range high performance fighter to escort bombers, much as the P-51 Mustang had done in its time. After being awarded a contract (AC-14582), McDonnell built two prototypes, designated the XF-88. The first prototype (#46-6525), powered by two Westinghouse XJ-34-WE-13 (3000 hp/2240 kW) flew from Muroc on 20 October 1948. Preliminary testing revealed that the top speed was a disappointing 640 mph (1,030 km/h) at sea level. After fitting McDonnell-designed afterburners, thrust was increased by 30% with corresponding performance increases in top speed, initial rate of climb and reduced takeoff distance.

Although the XF-88 won the "fly-off" competition against the competing Lockheed XF-90 and North American YF-93, the USAF (created in 1947) reevaluated the need for bomber escort and terminated the Penetration Fighter program in 1950. Analysis of Korean war missions, however, revealed that contemporary USAF strategic bombers were vulnerable to fighter interception. In 1951, the USAF issued a new requirement for a bomber escort with all major US manufacturers submitting designs. The McDonnell design was a larger and higher powered version of the XF-88, and won the bid in May 1951. The F-88 was redesignated the F-101 Voodoo in November 1951.

The new design was considerably larger, carrying three times the initial fuel load and designed around larger, more powerful J57 turbojets. The greater dimensions of the J57 engines required modifications to the engine bays, and modification to the intakes to allow a larger amount of airflow to the engine. The new intake also was designed to be more efficient at higher Mach numbers. In order to increase aerodynamic efficiency, reduce structural weight and alleviate "pitch-up" phenomena recently identified in flight testing of the D-558-2, an aircraft with a control surface configuration similar to the XF-88, the horizontal tail was relocated to the top of the vertical stabilizer, giving the F-101 its signature "T-tail". In late 1952, the mission of the F-101 was changed from "penetration fighter" to "strategic fighter", which entailed equal emphasis on both the bomber escort mission and on nuclear weapons delivery. The new Voodoo mockup with the reconfigured inlets, tail surfaces, landing gear, and dummy nuclear weapon was inspected by Air Force officials in March 1953. The design was approved, and an order for 39 F-101As was placed in May 1953 without any prototypes built.

Serial number 53-2418 was the first production A-model delivered to Edwards AFB in August of 1954. Its maiden flight was on September 29, 1954, with a McDonnell test pilot Robert C. Little. Test flight results: Mach 0.9 at 35,000 feet, with a maximum test speed to Mach 1.4. This aircraft is on display at the Pueblo Weisbrod Aircraft Museum, Pueblo Memorial Airport, Pueblo, CO.

The end of the war in Korea and the development of the jet-powered B-52 negated the need for fighter escort and Strategic Air Command withdrew from the program. The aircraft would be employed primarily as a two-seat air defence interceptor (F-101B), nuclear fighter bomber (F-101A/F-101C) and a reconnaissance platform (RF-101A/RF-101C) which saw service over Cuba and Vietnam.

The Voodoo's replacement as a fighter bomber would be the McDonnell Douglas F-4 Phantom II. While the Voodoo was a moderate success, it may have been more important as an evolutionary step towards the Phantom, one of the most successful Western fighter designs of the 1960s. The Phantom would retain the twin engines, twin crew for interception duties, and a tail mounted well above and behind the jet exhaust. Both aircraft were influenced by the same company's F-3 Demon, a carrier-based interceptor that served during the 1950s and early 1960s.

Wikipedia: F-101 Voodoo