Compass, Type B-3, Pre-WWII, Air Corps US Army Canberra The knob was used to

The knob was used to set the flow rate

A ring rotates a second lens

a fully synchronous radar system without provision for an optical bombsight tie-in

for the US Army Air Corps

and emergency conditions

Compass, Type B-3, Pre-WWII, Air Corps US Army Canberra The knob was used toHere is an original 1920's era Aircraft Compass Type B 3 made for aircraft of the Air Corps US Army. The compass card rotates within the housing that is suspended on vibration mounts to the left and right. The mounts are affixed to a bracket that was then mounted vertically to the instrument panel of the aircraft. At both top and bottom of the compass housing are compartments for compass correction rods. This example is exceptional given that the