Airspeed Indicator, Sensitive, 700 Knots, Army Type F-1A, US Army Air Force, WWII F7F Tigercat This particular protractor has a

This particular protractor has a tag from the US Naval Observatory stamped 1945

We have not found documentation of its use

When the wheels are retracted

The knurled dial around the face can be rotated by the pilot or crew member to the desired direction of flight

and therefore can only share what we can physically examine

Airspeed Indicator, Sensitive, 700 Knots, Army Type F-1A, US Army Air Force, WWII F7F Tigercat This particular protractor has aThe Army Type F 1A Airspeed Indicator was used across a number of US Army Air Corps and Air Force aircraft during WWII, including heavy bombers B 17, B 24, B 29, medium bombers B 25 and B 26, as well as light bomber A 20, according to the Accessories Interchangeability Chart dated Feb 1945. It was also used in versions of US Army Air Force WWII fighters P 38, P 39, P 40, P 47, and P 51. This F 1A was made by Kollsman, part number 739BU 03, and has a