Description
U.S. Air Force Type A-4 Gun-Bomb-Rocket Sight Amplifier, Drawing 667502, for F-100C Super Sabre
Item Overview
This U.S. Air Force Type A-4 Sight Amplifier was an electrical signal-amplifying and control unit in the Type A-4 Gun-Bomb-Rocket Sight system. The data plate identifies drawing 667502, serial number 8237, Air Force contract AF 33(600)-24095, and AC Spark Plug Division of General Motors as the manufacturer. An exact drawing-number match in the F-100C technical order documents this amplifier in F-100C-10 and F-100C-25 Super Sabre aircraft. It is a well-identified component from an early analog fire-control system developed for jet fighter and fighter-bomber operations.
Identification and Features
The identification plate names the component as a Sight Amplifier, Type A-4, for the Gun-Bomb-Rocket Sight. It was manufactured by AC Spark Plug Division, G.M.C., at Milwaukee, Wisconsin. Drawing 667502 is the key identifier linking this component to the F-100C installation. The Air Force contract number records its procurement under a military production contract, while serial number 8237 identifies the individual assembly.
- Component: Sight Amplifier
- Type: A-4
- Parent system: Gun-Bomb-Rocket Sight
- Drawing number: 667502
- Serial number: 8237
- Contract: AF 33(600)-24095
- Manufacturer: AC Spark Plug Division, General Motors Corporation
- Manufacturing location: Milwaukee, Wisconsin
- Documented aircraft: F-100C-10 and F-100C-25 Super Sabre
How It Worked
The amplifier received weak electrical signals from the A-4 sight computer and increased them to levels that could operate other parts of the sight. Its elevation and deflection channels amplified signals from the gyro pickoffs and sent them to torque motors in the sight head, which positioned the prediction mirror. The range channel controlled the sight’s range indication and reticle size. The sensitivity channel used corrected range information to control how strongly the gyros responded to aircraft movement. An air-density unit used an aneroid system to compensate for changes in air resistance on a projectile, while the automatic dive-bombing and electrical-cage relays supported other sight operating modes.
End-Item Application
Technical Order 1F-100C-2-4 lists the drawing 667502 sight amplifier in the radar bay at station 80 on the left-hand side of F-100C-10 and F-100C-25 aircraft. The F-100C was a fighter-bomber version of the North American F-100 Super Sabre, the first operational U.S. Air Force fighter capable of supersonic speed in level flight. The aircraft combined fixed cannon armament with external bombs and rockets, and the A-4 sight supplied the pilot with computed aiming information for these different weapons. The broader Type A-4 sight family also equipped aircraft such as the F-84G Thunderjet and F-86F Sabre, while drawing 667502 is specifically documented for the F-100C installation.
Historical Background
The Type A-4 was part of the early-1950s change from basic optical gunsights to integrated analog computing sights. These systems used gyros, range information, ballistic corrections, amplifiers, and a cockpit sight head to produce a moving aiming point. AC Spark Plug Division manufactured A-4 sight equipment for the Air Force during this period. By 1956, the Air Force included detailed A-4 operation and maintenance instruction in its fighter-weapons training material. The amplifier’s modular layout divided its major functions into separate channels and units, allowing military technicians to isolate faults and replace calibrated sections during field maintenance.
History of Use
The A-4 sight family served during the transition from Korean War-era jet fighters to the first generation of supersonic Air Force fighter-bombers. It supported gun and ground-attack missions in aircraft including the F-84G and F-86F before being installed in early F-100C production blocks. The F-100C entered operational service in 1955 and served with Tactical Air Command and later Air National Guard units. Air National Guard F-100Cs were deployed to Southeast Asia in 1968 and 1969 for combat operations. This amplifier’s exact drawing-number match connects it to the F-100C during an important period in the development of supersonic tactical aviation.
Condition
The identification plate is present and remains legible, allowing the type, drawing number, serial number, contract, manufacturer, and manufacturing location to be identified. The photographs should be reviewed for the exterior finish, electrical connectors, mounting points, hardware, and visible storage or handling wear on the item offered.
Ideal For
This documented F-100C sight component offers a focused addition to displays covering Cold War aircraft, early analog fire-control equipment, and the development of supersonic fighter-bombers. Its readable plate and exact aircraft drawing-number match support accurate identification in a museum, restoration, or technical collection.
- F-100C Super Sabre displays
- Cold War aircraft collections
- Early military-avionics exhibits
- Aircraft sight and fire-control collections
- AC Spark Plug and General Motors aviation displays
- Technical and educational reference
Approx length 14", Approx width 11", Approx height 6", Approx weight 17lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse