RAF WW2 Lancaster Air Position Indicator - Repeater Motor Unit MK1
Air Ministry Ref. 6B/314
Very good condition
The Lancaster used mechanical counters to display the longitude and latitude in degrees and minutes.
A mileage unit converted the forward air pressure from the pitot tube into a rotary speed such that this speed is proportional to the airspeed of the aircraft.
A flexible cable coupled this rotary output to the API and together with an electrical signal (compass bearing) from the master gyrocompass, produces an output on the 2 counters on the front, that read directly in degrees and minutes.
The repeater unit acts like a servo motor to drive a flexible cable.
