F-100 to F-108 Supersonic Fighters
Fighter designers have always wanted to make their products faster, and American engineers were the first to produce a supersonic fighter generation. This was possible because the nation’s financial and industrial resources could be called upon for a costly effort beyond the reach of most countries.
An aerodynamic research program, costing over $360 million, had produced a series of research aircraft beginning with the rocket-powered Bell X-l, which was launched from a B-29 into the world’s first manned supersonic flight on October 14, 1947. Another program developed advanced propulsion systems, and even more money went into the development of new machines for shaping light-alloy metal; enormous stretch-presses, heavy presses to squeeze out large forgings, and automatic precision machinery for cutting, drilling and riveting.
A North American company statement indicates how much more design effort was needed. While 300,000 engineering man-hours had been required to produce 15,485 P-51 fighters, 1,800,000 engineering man-hours produced 6,232 F-86 jets, and 4,800,000 engineering man-hours produced 2,294 supersonic F-100s.
After that proposal for a Mach 1.3 fighter was submitted to the Air Force on May 14, two prototypes were ordered November 1, 1951, along with a production commitment. The YF-100A designation was finalized on the 10th anniversary of the Pearl Harbor attack, beginning the “Century” series of supersonic Air Force fighters. The F-100 or “Hundred” eventually became the “Hun” in Air Force slang. Preceding fighter designations were soon forgotten: the F-95, -96, and -97 having reverted to F-86D, F-84F, and F-94C, while the Hughes F-98 became the Falcon air-to-air missile and the Boeing F-99 became the Bomarc “pilotless interceptor,” a surface-to-air missile.
A sense of urgency impelled the F-100 program ahead of the usual time schedule. The fear that the fast MiGs would soon have a supersonic successor, the desire of fighter pilots for more speed and altitude, and the awareness at the highest levels of command that 1957- the year of danger in war plan Dropshot (see Chapter 25) -was drawing near. A letter contract for the first 23 F-100As (NA-192) was given February 11, 1952, starting a contract for 273 approved by August 1952.
Pearl Harbor veteran George Welch exceeded sonic speed on the YF-100A’s first flight on May 25, 1953, at Edwards. He also flew the second YF-100A on October 14, and the first F-100A-l, which also used the J57-P-7, but had a shorter tail fin, on October 29. On the same day, LtCol. F.K. Everest flew the YF-100A to a 755-mph world speed record, the last time the rules required this record be set at less than a 100-foot altitude.
Pilots of TAC’s 479th Fighter Day Wing enthusiastically received the fast fighters in September 1954, but a hard blow struck the program. Four aircraft had been lost to inflight structural failure after loss of control, and George Welch was killed when the ninth F-100A-l disintegrated in a high-speed test dive on October 12, 1954. The Air Force grounded its entire F-100 inventory, waiting for the company to find out what was wrong.
The problem was that of directional stability, and fortunately the fix was relatively easy: an enlarged fin, extended wing tips and modified controls. These changes were made to all Super Sabres in the works and to those already delivered, and by February 1955, they were back in the air. By April 1955, 203 F-100As were completed, although they were operational only with the 479th Wing. The remaining Air Force day fighter strength then consisted of 12 F-84F, 13 F-86F, and three F-86H wings. (The 28 all-weather interceptor wings’ equipment has been described in Chapter 27). Top speed had risen from Mach .91 on the F-86A to Mach 1.285 (852 mph) at 35,000 feet on the F-100A.
Super Sabre armament consisted of four new 20-mm M-39 guns with 200 rpg, while two 1,000-pound bombs could replace the 275-gallon drop tanks, and two Sidewinder missiles were added in 1956. Six planes were converted to RF-100A camera versions in 1954, and four went to Taiwan in 1961. The Air Force soon found that besides higher performance, the F-100 brought costly problems.
Titanium, a rare heat-resistant metal combining strength and light weight, was used in the structure and helped raise the F-100A price past $1,014,000 per aircraft. A shortage of skilled maintenance men kept many aircraft on the ground in 1955. Accidents destroyed 287 aircraft and killed 91 men during the F-100’s first 750,000 flight time hours. Introducing supersonic fighters was also difficult for a Soviet counterpart, the MiG-19 first flown on January 5, 1954.
An F-100B project was diverted into the later YF-107 design, but on December 30, 1953, the F-100C fighter-bomber configuration had been selected for future Super Sabre production. The F-100C had the J57-P-21 (beginning with 101st a/c), more fuel, an air-refueling probe on the right wing, and wings strengthened to handle six 750-pound bombs, or a 1,680-pound Mk 7 nuclear weapon under the left wing, released by an MA-2 LABS, or two pods with 42 2.75-inch air-to-air rockets.
North American flew its first F-100C-l-NA from Los Angeles on January 17, 1955, and built 451 F-100Cs by April 1956. They entered service with TAC in July 1955. A second production source at Columbus, Ohio, began delivery of 25 F-100C-10-NH models in September 1955.
Added wing and tail area, and an autopilot, distinguished the F-100D ordered October 1954, and first flown January 24, 1956. Alternate underwing loads included either six 750-pound or four 1,000-pound bombs, two GAM-83A Bullpup missiles, a Mk 28 nuclear store, four AIM-9B Sidewinder air-to-air missiles, or two 450-gallon buddy air-refueling tanks. Production amounted to 940 F-100D-NA and 334 F-100D-NHs by August 1959, to which 339 two-seat F-100F trainers added by October 1959 brought the Super Sabre production total to 2,294.
Deliveries of F-100Ds to TAC began in September 1956. By June 1957, 16 TAC Wings used Super Sabres, and as more F-100Ds arrived, F-100A and F-100C models were passed to ANG squadrons, beginning in February 1958. Exports of 203 F-100Ds and 45 F-100Fs began in May 1958 when France began receiving 68 Ds and seven Fs for two escadres de chasse, serving with them until 1967. Denmark got 48 F-100Ds and 24 F-100Fs, beginning in June 1959, and Turkey received 87 F-100Ds in the same period. Eighty modernized F-100As went to Taiwan in 1959/60, plus 38 later transfers, and a few F-100Fs, and additional transfers brought the Turkish F-100 total to 260.