Knee Map Holder US Navy T93-H-202500 1948 AR-234

Knee Map Holder US Navy T93-H-202500 1948 AR-234This is an original Knee Map Holder as used by some pilots of the US Navy post WWII. According to the accompanying bulletin, the board is strapped to the pilots left leg with the map inserted between the plastic panel and the aluminum frame. There is a compass rose mounted to a flexible arm that can be positioned anywhere over the map. A small spring loaded chain can be extended around the center of the compass to the desired course to determine the

According to our friends at DeutscheLuftwaffe:

among others

It is the basic reference book for aircraft radio operators in the performance of their duties

This is a WWII-era pneumatic Valve

such as the airspeed and rate-of-climb indicators

time keeping instruments which are not affected by environmental extremes or system failure

B-24 turrets (nose and tail)

Here is a WWII-era Bombardiers' Information File published by the US Army Air Force May 1945

When translated

two remote controls are provided and

housed in a black aluminum case secured to the aircraft’s instrument panel

See illustration of the S-2E Tracker instrument panel from its Flight Manual showing the location of the indicator