First production aircraft capable of supersonic speeds in level flight
The
North East Aircraft
Museum's exhibit is ex-French Air Force and is on permanent loan from
the US Air Force. A small section of the aircraft is visible in a photograph
of decommisioned aircraft at RAF Sculthorpe, on Page 157
of North American F100 Super Sabre, David Anderton, (Osprey) .
Photo courtesy of Tony Oliver
The Super Sabre was the first production aircraft capable of sustained supersonic flight.
From February 1949, North American had started to think of ways to improve the performance of the F86 Sabre in order to produce a sonic aircraft. By September 1949, they had progressed on to thinking of ways to improve the F86D.
Early designs were rejected, but eventually on 1. November 1951, the US Air Force ordered two protypes of a design called the Sabre 45 (the number 45 coming from the angle of sweepback). On 7. December of the same year, the Air Force officially designated the aircraft as the F-100.
The first flight took place on 25 May 1953 from Edwards Air Force Base, and it exceeded the sound barrier on this very first flight. The pilot was George Welch (who was, incidentally, one of the few pilots to get airborne during the Pearl Harbor attack, and claimed four aircraft downed)
It was decided to use the F100 in an attempt on the world speed record - at the time the record was held by a Douglas XF4D-1 Skyray. However an attempt over the traditional 3 km . distance was unsuccessful because, although it achieved a higher speed than the Skyray, the rules required that the previous record should be exceeded by at least 1%. On 29. October 1953 another attempt was made over a 15 km. course -the rules stated that the fastest over either distance was the holder of the record, but the 15 km. course did not require the 1% margin to be exceeeded. A new world record was thereby attained, of 1215.25 km/hr by Lt. Colonel Pete Everest, flying at a height of about 30 meters above the ground, which was both the last low-altitude and the last subsonic record to be recorded (Everest was also the pilot for the previous attempt over the 3 km course, where he had achieved an average speed of 1,219.48 km/hr).
The new American Government under Eisenhower began to place noticeably more emphasis on nuclear weapons, with the result that Tactical Air Command was required to have an aircraft capable of delivering nuclear weapons, an area that had previously been the sole preserve of the Strategic Air Command. Since the F-100 was the only serious contender for such a role, from the beginning of 1954 plans were initiated to modify the aircraft as a fighter-bomber, the F-100C. (The F84F Thunderstreak could originally have filled this role, but problems arose in that program during 1953)
The F-100A became operational with USAF on 29. September 1954. Problems soon became apparent (in truth the program had proceeded at great pace, over-riding the reservations of many who expressed misgivings about the aircraft). On 12. October 1954, George Welch was killed when his aircraft broke up during tests. He was actually executing a supersonic pull-up which produces loads of more than 7g - he did eject but died later from his wounds. On 8. November an RAF pilot, Air Commodore Geoffrey Stephenson, was killed in Florida, and the following day another aircraft went out of control, but the pilot ejected safely. On 10. November 1954, all Super Sabres were grounded.
The solution was found to be a larger vertical tail. It was ironic that earlier prototypes had larger tails, but the size was reduced for production aircraft. The grounding order was lifted in February 1955.
Another "first" was achieved on 26. February 1955 when test pilot George F. Smith ejected at supersonic speed, claimed to be the first time anyone had done so above the speed of sound. He was apparently quite badly injured but recovered enough to fly again.
On 20 August 1955, an F-100C, piloted by Colonel Horace Hanes, gained a new world speed record of 1323.06 km/hr (Mach 1.25), the world's first supersonic record. This record attempt was made at a height of over 12000 meters, a departure from the extremely low-level attempts that had been carried out until then.
The F-100D is considered the full fighter-bomber version, as opposed to the F100C which was an adapted air superiority aircraft. It first flew on January 24. 1956. Various problems with the aircraft meant that by the early 1960's no two F100Ds were alike, causing major difficulties with spare parts and maintenance. Project High Wire was initiated to introduce standardization to the type.
With 1274 F100Ds being built, this type accounts for over 50% of the total Super Sabre production. Its comparatively short projected service life was lengthened by its commitments in Vietnam.
It incorporated the first autopilot designed for a supersonic aircraft.
In 1956, the Super Sabre was adopted by the Thunderbirds aerobatic team - their original machines were actually the first production F100Cs. In 1964, they switched to F-105 Thunderchiefs but a major accident in May apparently showed that this switch was a mistake and they re-equipped with the Super Sabre, although this time with the F100D variant, which they kept until switching to F-4E Phantoms in 1969.
They had one major incident on 21. October 1967 at Laughlin in Texas, when the wings fell off one aircraft during a pull-up, causing a major explosion as fuel from the wings entered the engine, but the pilot, Captain Merrill McPeak, ejected safely. An upshot of this incident was that restrictions were placed on F100s in Vietnam - several unexplained accidents had occured during a pull-up following the release of bombs.
The F-100 first entered the conflict in S.E. Asia on 9. June 1964. Flying from Da Nang (originally the major French military airfield) in South Vietnam, they were ordered to bomb a target in the Plaines des Jarres in Laos. Later in the year, two F-100s were shot down, in separate incidents, over Laos.
Bombing of North Vietnam began in 1965. The first air-to-air combat experienced by the USAF occured on 4. April 1965, when a force of F100s and F105s encountered some Mig-17s, with the loss of a couple of American aircraft. They were actually on a mission to destroy the Ham Rong bridge, identified as one of the two most important railway bridges in North Vietnam. To emphasis the difficulty of attacking bridges, this particular bridge survived 873 attacks on it until it was finally destroyed on 13 May 1972. By then, North Vietnam had built alternative bridges, so its strategic value was much less.
New airfields needed to be built in South Vietnam in order to accomodate modern aircraft. The Super Sabre was based at four of these new bases :- Bien Hoa, Phan Rang, Phu Cat and Tuy Hoa.
The F100 was assigned to "secondary" roles in Vietnam, being inferior to the F105 and later F4 as a tactical bomber. Apart from being inferior in range and bomb-loading, the F100 was totally unable to take the extreme structural loads required of low-level high-speed bombing. It was primarily responsible for bombing ground targets identified by ground forces, generally in the South. Sorties in the North required the use of the F105 or F4.
There were no Super Sabre aerial victories over enemy aircraft, and it appears that the general instruction on encountering enemy aircraft was to flee as quick as possible.
The maximum number of F100s stationed in Vietnam was 490. They were gradually withdrawn from the late 1960s. The last left Vietnam in July 1971.
It was supplied to France under the US Mutual Development Assistance Program which re-armed the air forces of friendly countries. France was actually the first foreign country to receive the Super Sabre, receiving 100 D and F versions.
Whilst a member of NATO, the French F100s were assigned to the main tactical bombardment role, including nuclear bombardment. After France left NATO in 1967, its role changed slightly, although they were still a major component of their air strength.
The first use of the Super Sabre in combat was carried out by the French, in Algeria ( although for these operations, the aircraft were still based in France ).
It began to be replaced in 1975, and were retired completely by the end of 1978, replaced by Jaguars.
The aircraft returned to US control, and were stored initially at RAF Sculthorpe in Lincolnshire.
For the first time in the US aircraft industry, titanium was used in a big way. Its heat resistance made it a particularly favored choice for the aft fuselage, adjacent to the engine. Titanium is about 40% lighter than stainless steel which has the same heat-resistant charachteristics. Each aircraft used 650 pounds of titanium, and in 1953 North American used 95% of the total American output of titanium. By 1954, the share had dropped to 60%, by when titanium was being produced more reliably and to a higher quality.
Ordinary tailplane in the disturbed wake, one piece all-movable placed low
Denmark
20 were delivered in 1959, followed by further deliveries in 1961. Suffered particularly from a bad safety record. Eight of the first ten F100F trainers crashed, as did 27 of 48 F100Ds. By 1968, a third of the fleet had been destroyed. Attempts to acquire more aircraft to replace those lost came to nothing - America needed all its F100s for Vietnam.
The F100 continued in the Danish Air Force, with a chequered career, until it began to be replaced in the late seventies, and was fully replaced by the early eighties.
Taiwan
First received aircraft in 1958. Apart from USAF, the only country to operate the F-100A (of which it received 118).
Turkey
Received aircraft from the late fifties.
Alleged to have seen much action in the 1974 conflict involving Cyprus.
It had 92 ex-USAF F100Cs and 181 F100Ds.