McDonnell F/RF-101 Voodoo
The McDonnell F-101 Voodoo twin-engined fighter was originally designed as a long range escort fighter to accompany the bombers of the Strategic Air Command if they were ever called upon to carry out their mission of nuclear strike against the Soviet Union. The Voodoo was destined never to serve in this particular role--it eventually emerged as a tactical reconnaissance aircraft, as a long-range interceptor, and as a nuclear strike aircraft. It was the first production fighter capable of exceeding 1000 mph in level flight. Only the reconnaissance version ever saw combat, flying the fastest combat missions ever flown (with the exception of the SR-71) during flights over North Vietnam. However, it was not without its flaws--in all its versions, the Voodoo had a tendency to pitch up into a nose-high attitude without warning, a problem which was caused by the way in which air flowed over its wings and under its high tail.
The F-101A was to be equipped with APS-54 radar and was to be armed with four 20-mm cannon as well as three Falcon air-to-air missiles and 12 unguided rockets. For ferrying purposes, the ammunition for the four 20-mm cannon could be replaced by a single 226-gallon auxiliary fuel tank.
The mockup was inspected in July of 1952. On May 28, 1953, the USAF issued an initial contract for 39 F-101As. No prototypes were specified, since the usual prototype stage was being skipped altogether.
The coming of peace in Korea in July of 1953 removed some of the sense of urgency connected with the F-101 program. By this time, the USAF had changed its mind and wanted McDonnell to redesign the aircraft so that it could not only carry out the originally-planned long-range escort mission but could also carry out nuclear strike missions. In May of 1954, the Air Force got cold feet about the wisdom of going directly into production with the F-101A and withdrew its authorization to proceed with quantity production and decided to wait until Category II flight tests could be carried out and all the required changes could be made. The target date for the completion of these tests was set for sometime in March of 1955.
The first F-101A (53-2418) was delivered in August of 1954, right on schedule. After completing some ground trials in St. Louis, it was shipped out to Edwards AFB. It took off on its maiden flight on September 29, 1954, McDonnell test pilot Robert C. Little being at the controls. He reached Mach 0.9 at 35,000 feet. Less than a month later, maximum speed had progressively been pushed to Mach 1.4.
In the meantime, the USAF had changed its mind yet again about its requirements. They now concluded that the range of the F-101A, impressive as it was, was not nearly large enough to be able to escort SAC's bombers all the way to the target. Consequently, the Strategic Air Command no longer believed in the viability of the F-101 concept and lost any interest in the aircraft as an escort fighter. Ordinarily, this would have been the end of the line for the F-101A project, and the F-101 would have been consigned to oblivion along with its XF-88 predecessor. Fortunately, the Tactical Air Command (TAC) saw the potential of the aircraft as a nuclear-armed fighter-bomber and requested that the F-101A be acquired by them under the aegis of Weapon System WS-105A. This designation corresponded to a short-lived Pentagon fad of assigning a "WS" number to its ships, tanks, and aircraft. Consequently, the F-101A that finally emerged became a hybrid aircraft, fitted with APS-54 radar and a MA-7 fire-control system for the air-to-air role, and a LABS (Low-Altitude Bombing System) for the delivery of nuclear bombs.
On October 28, 1954, the Air Force lifted its production hold order, permitting McDonnell to proceed with full-scale production. Three other F-101As were accepted before the end of 1954. They immediately began to undergo Category I flight tests. Category II flight tests began in January of 1955, and at this time, problems appeared with engine compressor stall. A redesign of the internal intake layout and engine compressor modifications cleared up these problems.
By mid-1956 the continued testing of the 29 F-101As which had been accepted by the USAF up to that time had turned up a number of structural, propulsion, aerodynamic, and armament problems. Perhaps the most serious of these was a tendency of the aircraft to pitch-up, a problem which was never fully corrected even after much effort. Brigadier General Robin Olds, who commanded a Voodoo wing, reported that it did not take very much to make a F-101A suddenly and without warning to go into pitch-up, even while cruising. The angle of attack needed to achieve lift with full flaps and drop tanks was very close to the pitch-up stall point, where the flow of air over the wings created a downflow over the tail slab. On January 10, 1956, Major Lonnie R. Moore, a Korean War ace with 10 kills to his credit, was killed in a F-101A pitch-up mishap at Eglin AFB, Florida.
Citing numerous still-unsolved problems with the F-101, in May of 1956 the USAF ordered that production be halted yet again. Although the hold order did not last very long, F-101A production remained limited to only eight airplanes per month throughout most of the remainder of 1956. During this period, McDonnell spent most of its time in modifying existing F-101As rather than in building new ones. Some 300 USAF-recommended changes were incorporated, plus some 2000 company-devised improvements.
It took a long time for McDonnell to develop any sort of cure for the pitch-up problem. McDonnell fitted an active inhibitor which helped to clear up the pitch-up problem, at least partially. Satisfied with the active inhibitor installed by McDonnell, the Air Force finally rescinded its May production restrictions on November 26, 1956. Nevertheless, the pitch-up problem was never completely cured, and remained a nuisance throughout the Voodoo's service life. Also never resolved was a problem encountered in retracting the forward-folding nosewheel--beyond a speed of about 90 mph, it simply would not go up.
The F-101A was armed with four 20-mm cannon and could carry a single 1620 lb or 3271-lb "special store", i.e., a nuclear bomb. The F-101As were equipped with the MA-7 fire control system as well with the LABS (Low-altitude Bombing System) for toss-release of their nuclear bombs. The F-101A could not carry or deliver conventional bombs.
The first Voodoo delivered to an operational unit was a F-101A which reached the 27th Strategic Fighter Wing at Bergstrom AFB on May 2, 1957. The last of 77 F-101As was delivered on November 21, 1957. Of the 77 F-101As accepted, only 50 of them actually reached operational units. The rest were used for experimental and test purposes to iron out various bugs and never attained actual service.
The first F-101A was bailed to General Electric in 1958 as a testbed for the J79-GE-1 turbojet. The designation NF-101A was assigned to this modification, the N prefix indicating a permanent change in configuration for test purposes. This aircraft was test flown with two J79s in 1958-59 before being retired to Amarillo AFB in Texas as a ground maintenance trainer.
On July 1, 1957, the 27th Strategic Fighter Wing was transferred to the Tactical Air Command and became the 27th Fighter-Bomber Wing. The Wing had previously operated the F-84F Thunderstreak. The F-101A was assigned the mission of nuclear strike, carrying a single nuclear bomb on its underfuselage centerline.
On September 25, 1958, an F-101A flew 1896 miles between Carswell AFB in Texas to Bermuda, completing the longest nonstop/nonrefuelled flight yet accomplished in a Century Series fighter.
Once the problem with the tendency to pitch-up had been addressed by the installation of an active inhibitor, the F-101A established an excellent safety record. In fact, the F-101A had the lowest first-year accident rate of any operational fighter in Air Force history.
The F-101A began leaving the USAF inventory in 1965-66, when 27 of them were transferred to the Air National Guard. By mid-1970, accidents, transfers, cannibalizations, and conversions had whittled down the USAF's F-101A fleet to only a couple of planes.
The ninth F-101A (53-2426) was bailed to Pratt & Whitney to serve as a testbed for the more powerful J57-P-55 engines planned for the F-101B interceptor. It was given the designation JF-101A, the "J" prefix indicating a temporary change of configuration for test purposes. The new engine installations offered an afterburning thrust of 16,000 pounds, and featured a large extension of the jetpipe to accommodate the longer afterburner section. Additional air scoops were installed underneath the rear fuselage for afterburner cooling. The JF-101A was used by Major Adrian E. Drew to set a new absolute world speed record of 1207.6 mph on December 12, 1957, taking the record away from the British Fairey Delta FD-2.
Specification of the F-101A: Engine: Two Pratt & Whitney J57-P-13 turbojets, 10,200 lb.s.t. dry and 15,000 lb.s.t. with afterburner.
Dimensions: wingspan 39 feet 8 inches, length 67 feet 5 inches, height 18 feet 0 inches, wing area 368 square feet.
Performance: Maximum speed 1009 mph at 35,000 feet. Initial climb rate 44,100 feet/min. Service ceiling 55,800 feet, combat ceiling 49,450 feet. Normal range 1900 miles, maximum range 2925 miles.
Weights: 24,970 pounds empty, 48,120 pounds gross, 39,495 pounds combat weight, 50,000 pounds maximum takeoff.
Fuel: Maximum internal fuel load was 2341 US gallons. A total of three under-fuselage drop tanks could be carried, bringing maximum fuel load to 3467 US gallons.
Armament: Four 20-mm Pontiac M-39 cannon in the nose with 200 rpg. A single "special store" (i.e., nuclear bomb) could be carried on the underfuselage centerline.
A single Canadian Voodoo was equipped as a specialized electronic countermeasures aircraft and was used as ECM aggressor aircraft in training. It was an ex-USAF F-101B (58-0300) which had been specially purchased in 1982 and given the Canadian serial number 101067. This aircraft were given the unofficial designation EF-101B in Canadian service. 101006 was a regular CF-101F that was assigned to 414 Squadron as a proficiency trainer for pilots flying 101067. 101006 was never designated EF-101B, contrary to what some other references say.