Sperry Aircraft Gyropilot Model A-3 Instruction Manual 1940 Armée de l'Air The US Army part number

The US Army part number 6208454 and GMC part number AC1567470 appear on the face of the instrument

A cool WWII-era aviation navigation artifact indeed

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and has a serial number prefix of AC42

thus putting the fixed lubber lines of the pelorus on this line

Sperry Aircraft Gyropilot Model A-3 Instruction Manual 1940 Armée de l'Air The US Army part numberThis is an authentic reference Sperry Aircraft Gyropilot Model A 3, Instructions No. 15 728A dated December 1940. The Gyropilot was an early automatic pilot system developed by Sperry which quickly became the standard system for private, commercial, and military aircraft of the day and during early WWII. This manual covers the 3rd generation of the Gyropilot: Model A 3, and its installation, operation, and maintenance. It is in reasonable condition