Tachometer, US Navy Mark V, Kollsman 621KN-04, 88-I-2500, SBD, TBM, F6F, PBY Seagull This is a Beam Compass

This is a Beam Compass Indicator

Was also installed with a "formation stick" controller in some aircraft

The knob turns the compass card when depressed

was based on the Rude form as modified by Elmer Collins of the United States Hydrographic Office

It is an exceptional specimen

Tachometer, US Navy Mark V, Kollsman 621KN-04, 88-I-2500, SBD, TBM, F6F, PBY Seagull This is a Beam CompassHere is a very nice example of the US Navy Mark V WWII post WWII era electric tachometer, made by Kollsman (part number 621KN 04), as used in aircraft of the US Navy such as the SBD Dauntless Dive Bomber, the TBM Avenger Torpedo Bomber, the F6F Hellcat Fighter, and the PBY5A Catalina Seaplane (which used 2). (See photos of the SBD and TBM instrument panels from their WWII era flight manuals showing the instrument location). It is in fine condition