The F-100 Super Sabre Overcame Significant Engineering Challenges To Become A Legendary Fighter Bomber
North American’s F-100 Super Sabre served the United States for 25 years. The Hun was the first American fighter jet capable of level supersonic flight. Progenitor of the Century Series, the F-100 was conceived in 1949 and developed during the 1950s- serving during some of the hottest years of the Cold War. North American’s justly famous F-86 Sabre jet fighter was the aircraft upon which the Hun was loosely based. One of the first American aircraft to incorporate significant amounts of titanium in its structure, the F-100 was much more than a redesigned F-86.
Bought Before It Was Built
The F-100 began as an unsolicited proposal for a supersonic day fighter to the United States Air Force (USAF). Because the F-100 was equipped with wings swept at 45 degrees it was initially dubbed the Sabre 45. North American’s mockup of the design was inspected on July 7th 1951, and after over a hundred modifications, the new aircraft was accepted as the F-100 on November 30th 1951. On January 3rd 1952 the USAF ordered two prototypes (YF-100As) to be followed quickly by 23 F-100As for delivery in February of 1952 and 250 more F-100As for delivery in August of 1952.
Deadly Sabre Dance
First flown in May of 1953, the YF-100A prototype performed so well that the F-100A went into production just five months later. But when Pearl Harbor hero and North American test pilot George Welch was killed in an early production F-100A during October of 1954 the cause was determined to be yaw instability-induced inertia coupling. Additional flight testing revealed that as the F-100A approached stall speeds, lift reduction on the outer wings could cause a violent pitch-up- the Sabre Dance.
Prone to Problems at First
Potentially deadly design issues notwithstanding, the F-100A was pressed into service quickly due to delays in the other fighter-bomber in development at the time, Republic’s F-84F Thunderstreak. The Hun went into service with the USAF Tactical Air Command (TAC) in September of 1954. TAC immediately requested that subsequently delivered F-100s be capable of “special weapons” (tactical nuclear weapons) delivery and that they keep the four 20 millimeter cannons mounted in the forward fuselage. However, no less than six major mishaps occurred within just two months. The entire fleet of F-100As was grounded until February of 1955.
Those Slick Chicks
One noteworthy modification program was the Slick Chick RF-100A photographic reconnaissance variant. Six F-100As were modified to fit cameras in place of the gun armament. Because the camera equipment would not all fit within the available space the engineers added a bulge that extended from below the windshield almost to the trailing edge of the wing. RF-100As apparently flew some highly sensitive missions over Soviet-occupied territories in Europe during some of the hottest days of the Cold War. Many of these missions are still classified today. After their service in Europe the Slick Chicks were used by the Taiwanese. Those missions are also still classified too.
Haste Makes Waste
The 479th Tactical Fighter Wing (TFW) based at George Air Force Base (AFB) in Victorville, California finally gained operational status during September of 1955. The experience of the 479th with the F-100A served to hasten both the replacement of the F-100A with the F-100C and the 479th to re-equip with Lockheed F-104 Starfighters within just three years. Other F-100As were all withdrawn from service by 1961 after 47 were lost to mishaps, recalled once when The Berlin Crisis took place, and finally retired by 1970 when replaced by other jets.
Better But Not Quite Yet the Right Jet
The F-100C was the fighter-bomber the USAF wanted and not what it needed. The F-100C retained most of the design deficiencies of the F-100A but could drop bombs. Equipped with an uprated Pratt & Whitney J57-P-21 turbojet engine that was as prone to compressor stalls as the previous version, the F-100C was later modified with yaw dampers to reduce instances of inertia coupling. Capable of carrying drop tanks but incapable of carrying all standard USAF ordnance, F-100Cs were phased out of service by 1970 after 85 of them were lost to operational mishaps.
So Much for Fighter Work
By the time the F-100D variant was introduced in 1956 the Hun had become a ground attack jet- an excellent ground attack jet, but nothing more. Other USAF fighters would take over the role of fighter-interceptor. The F-100D was equipped with extended wings and a larger vertical stabilizer, an autopilot and upgraded avionics. Later production F-100Ds could carry the AIM-9 Sidewinder infrared-guided air-to-air missile and the Martin GAM-83A / AGM-12 Bullpup air-to-surface missile. But not everything was rosy with the F-100D either.
Grounded Again But Still Serving
At first the F-100D was plagued by electrical system problems, landing gear and brake parachute malfunctions, and the inflight refueling probes had a tendency to part with the aircraft during high speed maneuvers. Due to inconsistent application of field or depot fixes for these issues it became necessary to review the entire fleet of 700 aircraft to standardize them. This was eventually accomplished via the High Wire standardized modification program. Later the Combat Skyspot program added X band radar to facilitate ground-directed bombing day or night by F-100Ds.
The Crucible: Air War in Vietnam
The Hun served in Southeast Asia longer than any other American jet. They served as MiG combat air patrol (MiGCAP) escorts for F-105 Thunderchiefs and other fighter-bombers, as Misty forward air controllers (FACs), and when modified with radar receiving equipment to employ anti-radar missiles like the AGM-65 Shrike, in the defense suppression or Wild Weasel roles. During a MiGCAP escorting F-105s attacking the Thanh Hoa bridge, F-100s also fought the first air-to-air jet combat of the Vietnam war, shooting down three North Vietnamese MiG-17s- even though they were never officially credited as aerial victories.