Autopilot Turn Controller for A-5 Auto Pilot System, Sperry, B-24 Liberator
The A-5 Automatic Pilot was used primarily in WWII-era bomber aircraft of the Air Corps US Army such as the Consolidated B-24 Liberator (see photo of B-24 cockpit showing the location of the A-5 panel). The A-5 system appeared in aircraft manufactured during or before 1943, the year when the Honeywell C-1 system became the standard autopilot system for large multi-engine aircraft. Theoretically, the A-5 system may also have appeared in the Boeing B-17 Flying Fortress as well as bomber-trainer aircraft, but we've not yet found documentation to support this assumption. The A-5 was normally paired with the Sperry T-1 Bomb Sight system.
This is the "Turn Controller", Sperry part number 647409, one of 15 components of the A-5 system (see diagram of system, spec sheet, and pages from B-24G-M Manual dated 1945 showing location of the controller).
The bottom knob controlled the turn, the center knob adjusted the rudder alignment for yaw, and the top knob adjusted the angle of the bank. It is in good condition for its age.