Description
Verification Note: The original part number 800757762 contained a transcription error. The correct General Electric part number is 8007577G2.
WWII B-29 Upper Ring Sight Azimuth Gearing Assembly, GE P/N 8007577G2, Less Selsyns
Item Overview
This World War II General Electric Gearing Assembly, Azimuth was used in the B-29 Superfortress upper ring sighting station. It was part of the Model 2CSR3A1 sighting station used by the aircraft’s upper gunner.
The assembly was mounted on the rotating inner ring of the sight. When the gunner moved the sight left or right, this gearing engaged a stationary ring gear. It then drove two electrical Selsyn transmitters.
The one-speed Selsyn provided coarse position data. The 31-speed Selsyn provided more precise position data. These signals told the B-29’s central fire-control system where the sight was pointed in azimuth.
This is sight-position transmitting gearing. It is not a turret-drive gearbox, complete gunsight, fire-control computer, or complete sighting station.
Identification and Markings
- Official nomenclature: Gearing Assembly, Azimuth
- General Electric part number: 8007577G2
- Manufacturer: General Electric
- Aircraft: Boeing B-29 Superfortress
- End item: Upper Ring Sighting Station
- Sighting-station model: 2CSR3A1
- Fire-control system: General Electric Model 2CFR55B1
- Complete station A.E. reference: 52-6869
- Complete station GE drawing: W-8258820, Group 1
- Package date: May 1944
- Package configuration: “Less Selsyns”
Included and Excluded Components
- Includes the azimuth gearing assembly
- Does not include the one-speed Selsyn transmitter
- Does not include the 31-speed Selsyn transmitter
- Does not include the complete upper ring sight
- Does not include a fire-control computer
- Does not include a turret-drive assembly
Historical Background
The B-29 was the first production aircraft to use analog computers to remotely aim and fire aircraft gun turrets. This was one of the aircraft’s most advanced features.
The system let B-29 gunners work from inside the pressurized crew area. They did not have to sit inside most of the aircraft’s gun turrets. The smaller remote turrets also created less drag.
The upper gunner sat in a raised seat under the top viewing dome. This seat was often called the “barber chair.” The gunner used the ring sight to track attacking aircraft. He could direct the upper gun turrets when they were assigned to his station.
The central fire-control computer corrected for ballistics, target lead, and parallax. This gearing assembly did not make those calculations. Its job was to drive the Selsyn transmitters that supplied the gunner’s azimuth position to the system.
The package is dated May 1944. This was the same period when the B-29 was entering combat service. Its first combat missions followed in June 1944. This assembly represents an important mechanical link within one of World War II’s most advanced aircraft gun-control systems.
Condition
The package is dated May 1944 and marked “Less Selsyns.” The two electrical Selsyn transmitters are not included. No operational or testing information was provided. Review the pictures for markings, storage wear, corrosion, missing hardware, and other condition details.
Ideal For
- B-29 Superfortress restoration projects
- World War II aviation museums
- B-29 central fire-control system displays
- Historic aircraft gunsight collections
- Early analog-computing exhibits
- General Electric military equipment collections
- Aviation education and reference displays
Approx length ", Approx width ", Approx height ", Approx weight lbs.
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, condition than was shown in the pictures.
Please visit our page about order lead times here: Order Lead Times
Suggested Keywords (SEO): B-29 ring sight gearing assembly, General Electric 8007577G2, B-29 azimuth gearing assembly, 2CSR3A1 upper ring sight, B-29 central fire-control system, B-29 Selsyn gearing, WWII aircraft gunsight parts, B-29 restoration parts, General Electric military aviation parts, B-29 Superfortress gunner station, WWII B-29 sight gearing assembly for sale