Project High Wire was a United States Air Force modernization programme for selected North American Aviation F-100Cs, Ds and Fs Super Sabre that were still in active inventory. It consisted of two detailed modification groups: significant electrical rewiring upgrade, and heavy aircraft maintenance and IRANi upgrade. These upgrades began in 1962.
Rewiring upgrade operation consisted of replacing old wiring and harnesses with improved maintainable designs. Heavy maintenance and IRAN included new kits, modifications, standardized configurations, repairs, replacements and complete refurbishment.
Source: USAF F-100C Super Sabre - Flight Manual - Technical Order Upgrades T.O. 1F-100C(I)-1S-65 2 February 1971
A modification program of changes in maintenance procedures, major wiring harnesses, IRANi upgrade, and additional avionics.
Improved nose gear ground safety lock instructions
Improved use of 200 US gal (760 L). drop tanks and installation on outboard pylons
Restriction on takeoff with partially filled 450 US gal (1,700 L). drop tanks
Improved use of braking system with thermal expansion after high altitudes to prevent excessive pressures and system failures.
Improve instructions on all ejection seat systems at low altitude bailouts
A modernization programme of 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.
List of changes and rescinded(R)
Loose strap end securing
Main gear tire failure landings
g limitations - R
Spin recovery and canopy warning light
Additional information on external store index system
Oxygen mask hose rerouting
Warning light on fuel shutoff switch – R
Additional loading configuration for Mk-82 and Snakeye I (Mk-82 w/drag fins) bombs
"CAUTION" note on tail skid
In-flight refueling ready light
Addition stores index numbers
Landing pattern usage
A/A37U-15 Tow Target index numbers
Turn-and-slip indicator information
Additional store information
Store index numbers for MK-82 bomb with 36-inch (910 mm) fuze extender
Store index numbers for Destructor M117D
Dispensing of C/B munitions – R
Store index numbers airspeed limits for CBU-24
Bomb arming switch information
Salvo of armed bombs
Flight limits for BLU-52/B bomb (chemical)
BLU-32/B Fire Bomb un-finned
Modification of oil pressure relief valve
Information of AIM-9E air-to-air missile
90 degree rotation of A/ARC-34
Information of SUU-20/A Practice Dispenser
Relocation of sight selector unit
Installation of data recording system
High stresses in the N2 Compressor of the J57-21, -21A engines
Installation of 450 US gal (1,700 L). air refueling drop tanks and gauges
Installation of in-flight refueling probe extension
Installation of AIM-9B provisions
Installation of true airspeed indicator
Provisions for in-flight refueling of external tanks
Installation of EPR system
Installation of ILS AN/ARN-31 system
Removal of supplementary oil tank
Standardization of takeoff trim setting
90 degree rotation of AN/ARC-34
installation of canopy breakaway tool
modification of dispenser and rocket system
installation of variable intensity light control
automatic electrical caging – A-4 sight
deactivation of attitude indication system during ground maintenance
installation of fuel system shutoff valve fail light
installation of relay in gun camera circuitry
installation of exterior floodlights
installation of data recording equipment
installation of cockpit selectable hi-lo drag bomb capability
installation of anticollision lights
relocation of variable rocket depression unit
automatic throttle positioning in case of throttle linkage failure
modification of fuel control and addition of extended range afterburner
modification of engine fuel pump transfer valve
modification of oil pressure relief valve
Information on arresting systems and approach end engagements
Information of fuel system shutoff valve
Flight limits on SUU-20/A practice dispensers with BDU-33/B, -33A/B, -33B/B bombs
Information on SUU-20 series
Information on LAU-3 Rocket Launcher
Operating procedures on HBU-2B/A Lap Belt
Information on minimum altitude of attempting an air start
Information on wind-blast injury during ejections
High stresses in the N2 Compressor
Information on pitch damper system deactivation
Information on partially filled 355 US gal (1,340 L). and 275 US gal (1,040 L). drop tanks
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
Block No.s.......
S/N Range......................
Block number change
F-100C-1-NA .... AF 53-1709 to –1778 ... F-100C-2-NA
F-100C-6-NA .... AF 54-1770 to –1814
F-100C-11-NH ... AF 55-2709 to –2733
F-100C-16-NA ... AF 54-1615 to –1859
F-100C-21-NA ... AF 54-1860 to –1969
F-100C-26-NA ... AF 54-1970 to –2120
Note: NA – Los Angeles, CA and NH – Columbus, OH
F-100Ds and Fs
Source: USAF F-100D,F Super Sabre - Flight Manual - Technical Order: 1F-100D(I)-1S-120 dated 12 January 1970
This project 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. All manuals will have the Roman numeral (I) added after the aircraft number (i.e. T.O. 1F-100D(I)-1S-120, 12 January 1970
Approximately 700 D-models had been modified with Project High Wire.
This upgrade is 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:
VGHb A/A24U-10 Recorder
Magnetic tape media
Records during gun firing, store release, in-flight refueling, change in nose gear load switch position
Powered by the primary bus
TRK-77/A24U Accelerometer
VGH REC/LDG POS CONTROL, no cockpit controls
Includes previous T.O. -1S-nnn
supplemental upgrades, as nnn
listed below:
-119 Relocation of Sight Selector Unit and relocation of Variable Rocket Depression Unit
-118 Information on ECM Pod QRCc-160-8 (AN/ALQ-87)
-117 Information on variety of ordnance and special stores
-116 Classified
-115 For F-100Fs
-114 Classified
-112 Modified Oil Pressure Relief Valve for J-57
-111 Relocation of Fuel Boost Pump and test switch
-110 CBU-42/A authorization
-109 BLU-32/B Firebomb Unfinned
-108 Information on CBU-37/A
31 August 1967 - 15 December 1969
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):
Loose strap end securing
Main gear tire failure landings
G limitations - R
Spin recovery and canopy warning light
Additional information on external store index system
Oxygen mask hose rerouting
Warning light on fuel shutoff switch - R
Additional loading configuration for MK-82 and Snakeye I Bomb
CAUTION note on tail skid
In-flight refueling ready light
Addition stores index numbers
Landing pattern usage
A/A37U-15 Tow Target index numbers
Turn and slip indicator information
Additional store information
Store index numbers for MK-82 with 36-inch (910 mm) Fuse Extender
Store index numbers for Destructor M117D
Dispensing of C/B munitions - R
Store index numbers airspeed limits for CBU-24
Bomb arming switch information
Salva of armed bombs
Flight limits for BLU-52/B bomb
BLU-32/B Fire Bomb un-finned
Modification of oil pressure relief valve
Information of AIM-9E air-to-air missile
90 degree rotation of A/ARC-34
Information of SUU-20/A Practice Dispenser
F-100 "G" restrictions
High stresses in the N2 Compressor of the J57-21, -21A engines
Installation of 450 US gal (1,700 L). air refueling drop tanks and gauges
Installation of in-flight refueling probe extension
Installation of AIM-9B provisions
Installation of true airspeed indicator
Provisions for in-flight refueling of external tanks
Installation of EPR system
Installation of ILS AN/ARN-31 system
Removal of supplementary oil tank
Standardization of takeoff trim setting
90 degree rotation of AN/ARC-34
installation of canopy breakaway tool
modification of dispenser and rocket system
installation of variable intensity light control
automatic electrical caging - A-4 sight
deactivation of attitude indication system during ground maintenance
installation of fuel system shutoff valve fail light
installation of relay in gun camera circuitry
installation of exterior floodlights
installation of data recording equipment
installation of cockpit selectable hi-lo drag bomb capability
installation of anticollision lights
relocation of variable rocket depression unit
automatic throttle positioning in case of throttle linkage failure
modification of fuel control and addition of extended range afterburner
modification of engine fuel pump transfer valve
modification of oil pressure relief valve
Information on arresting systems and approach end engagements
Information of fuel system shutoff valve
Flight limits on SUU-20/A practice dispensers with BDU-33/B, -33A/B, -33B/B bombs
Information on SUU-20 series
Information on LAU-3 Rocket Launcher
Operating procedures on HBU-2B/A Lap Belt
Information on minimum altitude of attempting an air start
Information on wind-blast injury during ejections
High stresses in the N2 Compressor
Information on pitch damper system deactivation
Information on partially filled 355 US gal (1,340 L). and 275 US gal (1,040 L). drop tanks
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:
Block No.s......
S/N Range......
Block number change
YF-100A-NA....52-5754/55
F-100A-01-NA 52-5756 ~ 5765
F-100A-05-NA 52-5766 ~ 5778
F-100A-10-NA 53-1529 ~ 1568
F-100A-15-NA 53-1569 ~ 1608
F-100A-20-NA 53-1609 ~ 1708
F-100C-01-NA 53-1709 ~ 1778..F-100C-02-NA (See F-100C High Wire Descriptions)
F-100C-05-NA 54-1740 ~ 1769..F-100C-06-NA
F-100C-10-NA 54-1770 ~ 1814..F-100C-11-NA
F-100C-15-NA 54-1815 ~ 1859..F-100C-16-NA
F-100C-20-NA 54-1860 ~ 1970..F-100C-21-NA
F-100C-25-NA 54-1971 ~ 2120..F-100C-26-NA
F-100C-10-NH 55-2709 ~ 2733..F-100C-11-NA
F-100D-01-NA 54-2121 ~ 2132
F-100D-05-NA 54-2133 ~ 2151
F-100D-10-NA 54-2152 ~ 2221
F-100D-15-NA 54-2222 ~ 2303
F-100D-20-NA 55-3501 ~ 3601
F-100D-25-NA 55-3602 ~ 3701..F-100D-26-NA
F-100D-30-NA 55-3702 ~ 3814..F-100D-31-NA
F-100D-35-NH 55-2734 ~ 2743
F-100D-40-NH 55-2744 ~ 2783
F-100D-45-NH 55-2784 ~ 2863..F-100D-46-NA
F-100D-50-NH 55-2864 ~ 2908..F-100D-51-NA
F-100D-55-NH 55-2909 ~ 2954..F-100D-56-NA
F-100D-60-NA 56-2903 ~ 2963..F-100D-61-NA
F-100D-65-NA 56-2963 ~ 3022..F-100D-66-NA
F-100D-70-NA 56-3023 ~ 3142..F-100D-71-NA
F-100D-75-NA 56-3143 ~ 3198..F-100D-76-NA
F-100D-80-NH 56-3351 ~ 3378..F-100D-81-NA
F-100D-85-NH 56-3379 ~ 3463..F-100D-86-NA
F-100D-90-NA 56-3199 ~ 3346..F-100D-91-NA
F-100F-01-NA 56-3725 ~ 3739..F-100F-02
F-100F-05-NA 56-3740 ~ 3769..F-100F-06
F-100F-10-NA 56-3770 ~ 3919..F-100F-11
F-100F-15-NA 56-3920 ~ 4019..F-100F-16..(~4016)
____________58-6975 ~ 6983
____________59-2558 ~ 2563
F-100F-20-NA 58-1205 ~ 1233..F-100F-21
Total Production 2,294
Note: NA - Los Angeles, CA and NH - Columbus, OH
