Airspeed Indicator, 500MPH, Army Type D-7, US Army Air Force, WWII F-80 It has two markers

It has two markers

The 7-component Flux Gate Compass system was designed to provide accurate navigational guidance using the earth's magnetic forces by minimizing interference from the systems of the aircraft

There are some markings on the glass denoting the operating limits and orientation of the glass (the white mark

the course correction is calculated and communicated to the pilot

Measures 3 inches diameter and 1 inch deep

Airspeed Indicator, 500MPH, Army Type D-7, US Army Air Force, WWII F-80 It has two markersThe Army Type D 7 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 D 7 was made by Kollsman, part number 586BK 028, and has a