Project High Wire was a United States Air Force (USAF) modernization programme for selected North American Aviation F-100C, D and F Super Sabres that were still in active inventory. It consisted of two detailed modification groups; significant electrical rewiring upgrade, and heavy aircraft maintenance and IRAN (inspect and repair as necessary) upgrade. These upgrades began in 1962.[1]
Rewiring upgrade operation consisted of replacing old wiring and harnesses with improved maintainable designs while heavy maintenance and IRAN included new kits, modifications, standardized configurations, repairs, replacements and complete refurbishment.[2]
The F-100Cs first saw action in March 1954 before officially entering USAF service on 14 July 1955 with the 450th Fighter Wing, Foster AFB.[3] The aircraft was known for its efficacy as a platform for nuclear toss bombing due to its high top speed, although it shared a number of flaws with the F-100As.[3] Key changes introduced by the modification program included changes in maintenance procedures, major wiring harnesses, IRANi upgrade, and additional avionics. By 1968, Project High Wire implemented the following upgrades:
The modernization programme adopted in 1970 involved 3 simultaneous operations: an electrical rewiring operation, and a heavy maintenance improvements and IRAN operations. Also including design changes, safety instructions, aircraft characteristics, normal and emergency operations, and overall aircraft and documentation standardization.
Project High Wire modifications were extensive and dictated a change in the block number assignment, i.e.: F-100C-10-NH to F-100C-11-NH
Note: NA – Los Angeles, CA and NH – Columbus, OH
The F-100D was also a fighter-bomber but an improved version of the F-100C. One of its notable features was the wing outfitted with an increased root chord, which expanded the total wing area to 400.18 square feet.[4] It also has landing flaps, which gave the aircraft its crank-wing trailing edge - one of its distinguishing features. While the aircraft's first aerial demonstration performance ended in disaster after the plane exploded, it still went on to become the most celebrated and widely produced variant of the F-100.[5]
Project Highwire modified approximately 700 F-100D models.[6] The changes required all new manuals (TOs)a and incremented (i.e. -85 to -86) block numbers. All later production models, especially the F models, included earlier High Wire mods. New manuals included colored illustrations.
This upgrade was to provide aircrew information on aircraft for installation of Data recorder (DR) equipment. DR is to record basic information on flight conditions i.e., velocity, G-force, and altitude. This data will be used to study the results of various mission requirements and determine the effects on the fatigue life of the aircraft structures:
A modernization programme of 2 simultaneous operations: an electrical rewiring operation, and a heavy maintenance improvements and IRAN operations. Also including design changes, safety instructions, aircraft characteristics, normal and emergency operations, and overall aircraft and documentation standardization. List of changes and rescinded(R):
D-model High Wire modifications were also performed on A-models and previously upgraded C-models. Most D-model modifications mandated the change in the block number of the aircraft; thus increasing the block number by one unit value, i.e.: F-100D-10-NH to F-100D-11-NH.
Serial Number Information:
Total Production 2,294
Note: NA - Los Angeles, CA and NH - Columbus, OH