The F-100F two-seat Super Sabre originated on May 10, 1954 in a North American design study for a supersonic trainer version of the F-100 single-seat day fighter. The initial in-service accident rate of the Super Sabre had been alarmingly high, and it was suspected that part of the problem might be the inexperience of its pilots. It was thought that a two-seat trainer version might help green pilots get used to this hot new supersonic aircraft. On September 2, 1954, the USAF offered to loan NAA a standard F-100C for conversion to trainer configuration under the designation TF-100C.
In December of 1955, a contract was issued for 259 TF-100Cs, the contract being accompanied by a corresponding reduction in F-100D procurement.
The USAF loaned F-100C 54-1966 to North American for the conversion to two-seat configuration, and the converted TF-100C flew for the first time on August 3, 1956, NAA test pilot Alvin S. White being at the controls. The company designation was NA-230. The TF-100C lacked all operational equipment. On April 9, 1957, the TF-100C was lost when it spun into the ground and crashed during a spinning test. Fortunately, test pilot Bob Baker ejected safely.
In the meantime, the two-seat Super Sabre concept had evolved into a combat trainer under the company designation of NA-243. The USAF designation was changed to F-100F. Full combat capability was to be retained and the same underwing loads as the F-100D were to be carried. However, the internal armament was reduced to two 20-mm cannon rather than the four guns of the F-100D. The front cockpit contained all the controls for the armament.
The first production F-100F (56-3725) was flown on March 7, 1957, NAA test pilot Gage Mace being at the controls.
First deliveries of the F-100F began to the USAF in January of 1958, and by the end of that year, F-100Fs had reached most of the overseas units that were operating F-100Ds.
The F-100F-20-NA (company designation NA-255) was a special production model developed at the specific request of the Pacific Air Forces. It was equipped with a navigational system including an AN/ASN-7 dead-reckoning computer, a PC-212 Doppler radar, and a standard J-4 compass system. It had modified flaps with a spanwide duct built into the leading edges to direct air from the lower surface over the upper to reduce buffeting during landing. The flaps had a full deflection angle of 40 degrees, as compared to the 45-degree angle of deflection for the standard F-100D and F.
The last of 339 F-100Fs was delivered in October of 1959. All of them were built at NAA's Los Angeles plant. Included in this total were 45 aircraft specifically purchased for the Military Assistance Program and intended for export to US allies overseas. Total Super Sabre production finally totaled 2294, including 359 built at Columbus.
In 1959, fifteen F-100Fs were modified to carry the GAM-83A Bullpup air-to-surface guided missile.
The same engine malfunction problems, wing structural failures, spare and parts shortages, and component deficiencies that bedeviled the F-100D were also experienced by the F-100F, which is not all that surprising since they were basically the same airframe. In 1962, all F-100Fs (along with their F-100D single-seat cousins) began to go through *Project High Wire*, which was an extended program to standardize the weapons delivery system which had been modified on so many separate occasions that individual aircraft ended up with significant differences from each other, making for a maintenance and spare parts nightmare.
When American bombing raids against North Vietnam began in 1964, combat losses of US aircraft began to mount. Many of these losses were caused by the increasingly effective use by the North Vietnamese of radar-guided surface-to-air missiles. Someone in the USAF got the bright idea that the best way to defeat the surface-to-air missile threat was to destroy or otherwise shut down their guidance radars, leaving enemy missile sites effectively blind and impotent.
In 1965, several F-100Fs were modified for the role of identifying, marking, and attacking North Vietnamese SAM sites, particularly their radar installations. Applied Technology Inc. did much of the early work. This company began by adapting electronic equipment that had originally been developed for the U-2. In the system which eventually emerged, the F-100F was provided with an AN/APR-25 radar homing and warning receiver which was capable of detecting the S-band signal emitted by the North Vietnamese SA-2 fire control radar as well as the C-band signal emitted by upgraded SA-2 systems and the X-band signals emitted by enemy airborne interception radars and radar-guided antiaircraft artillery. A cockpit display included a "threat panel" plus a cathode-ray tube which showed the bearing of the threat signal. An AN/APR-26 receiver was fitted which detected missile guidance launch signals by sensing a power change in the enemy's command guidance radar signal and flashed a red launch warning signal light in the cockpit. An IR-133 receiver was fitted, this receiver having a greater sensitivity than the APR-25 homing and warning receiver and having the additional capability of indicating the nature of the threat by signal analysis.
The modified F-100Fs carried the usual load of 20-mm cannon ammunition plus a pair of LAU-3 canisters loaded with 24 rockets which served as markers as well as weapons which could demolish a radar site. Fighter-bombers accompanying the F-100F would then attack the target with iron bombs. The project was given the name *Wild Weasel*, after the fierce little mammal which has a reputation of being so fearless that it pursues its prey into its very den.
Wild Weasel F-100Fs included 58-1221, 1226, 1227, 1231, 1212, and 1232. The first F-100F Wild Weasel I aircraft arrived in Southeast Asia in November of 1965. The first Wild Weasel F-100F combat mission was flown on December 3. The missions were flown under the codename *Iron Hand*, and the antiradar missions were usually flown by one F-100F accompanied by four F-105s. The F-100F would identify and mark the radar site for attack by the accompanying F-105Ds.
Three additional Wild Weasel I aircraft arrived in SEA on February 27, 1966, also to participate in the *Iron Hand* anti-SAM campaign. Later, F-100Fs carried AGM-45A Shrike antiradiation missiles. The Shrike missile contained a passive homing system which detected the enemy radar beam and followed it all the way back to its source. The first combat use of the Shrike was on April 18, 1966, when F-100Fs themselves began attacking North Vietnamese radar sites.
On August 11, 1967, Lt.Col. James E. McInerney Jr and Capt. Fred Shannon in an F-100F led a mission that destroyed six SAM sites and damaged four, clearing the way for a strike on Hanoi's Paul Doumer Bridge.
The F-100F Wild Weasel I program claimed credit for nine confirmed SAM radar kills. An undetermined number of other enemy radars were forced off the air as a result of Wild Weasel I activities. Two F-100F Wild Weasel I aircraft were lost in action.
Having proven the general concept, the F-100F Wild Weasel I was eventually replaced by the F-105F Wild Weasel III and the F-4 Wild Weasel IV
F-100Fs also flew as forward air controller (FAC) aircraft, replacing lighter planes such as the Cessna O-2 Bird Dog in this role. This switch was made after enemy antiaircraft made it too hazardous for light planes to operate, especially in areas where there were SAMS, AAA, or the threat of MiGs. The crew member in the rear seat had the maps, carried a hand-held strike camera, and communicated by radio with the fighters in the strike team. When the strike team arrived at the target, the pilot would fire the markers and the rear seat would direct the strike. These high-speed FAC missions were flown under the codename *Misty*.
As F-105s and F-4s became available in quantity, F-100Fs were phased out of the active Air Force inventory and passed along to the Air National Guard. The Air National Guard had received an initial batch of six F-100F in 1958, but acquired very few more until the late 1960s because of the needs of the Vietnam war. As the 'sixties came to an end, the pace at which F-100F left Air Force service quickened and large numbers of F-100Fs began to reach the Guard. By June of 1972, almost all F-100Fs were out of USAF service, and a hundred F-100Fs were in service with the ANG.
Even though the F-100F had originally been designed as an operational trainer intended to familiarize pilots with supersonic flight, its safety record was just as atrocious as that of its single-seat F-100D version. About a quarter of all F-100Fs built were destroyed in accidents. This leads one to suspect that it wasn't just a problem with pilot training that was the cause of the Super Sabre's high accident rate, but basic problems with the aircraft itself.
The first F-100F (56-3725) was modified by the USAF Systems Command's Aeronautical Systems Division for testing of very steep approaches and very fast landing speeds. This work was done in preparation for the X-15 and Dyna-Soar programs. In order to perform these tests, means had to be found to build in a large additional drag which could be added or removed on command. This was done by replacing the drag chute and afterburner by a thrust reverser that could be operated in flight. In addition, the standard belly airbrake was replaced by a special perforated air brake with almost three times the area. The use of these features enabled the F-100F to touch down at 230 mph rather than the usual 155 mph.
56-3725/3739 North American F-100F-1-NA Super Sabre (NA-243) 56-3740/3769 North American F-100F-5-NA Super Sabre (NA-243) 56-3770/3919 North American F-100F-10-NA Super Sabre (NA-243) 56-3920/4019 North American F-100F-15-NA Super Sabre (NA-243) 58-1205/1233 North American F-100F-20-NA Super Sabre (NA-255) 58-6975/6983 North American F-100F-15-NA Super Sabre (NA-261) - for MDAP 59-2558/2563 North American F-100F-15-NA Super Sabre (NA-262) - for MDAP
Engine: One Pratt & Whitney J57-P-21/21A turbojet, 10,200 lb.st. dry and 16,000 lb.st. with afterburning. Dimensions: Wingspan 38 feet 9 inches, length 50 feet 0 inches, height 16 feet 2 3/4 inches, wing area 400 square feet. Performance: Maximum speed 760 mph at sea level, 852 mph at 35,000 feet. Initial climb rate 23,800 feet/minute. Service ceiling 44,900 feet, combat ceiling 51,000 feet. Normal range 358 miles, maximum range 1294 miles. Fuel capacity 1294 US gallons. Weights: 21,712 pounds empty, 31,413 pounds combat, 39,122 pounds maximum takeoff. Internal armament consisted of two 20-mm Pontaic M-39 cannon. Underwing loads could include up to 5000 pounds of bombs and fuel tanks on six stations.