Theory of Flight, Technical Manual, TM 1-400 Feb 1941 F-84 This D-7 was made by

This D-7 was made by Kollsman

and paired with one more dual tachometer for engines 3 & 4 in heavy bombers such as B-17 Flying Fortress

includes at the back an interesting 12-page Technical Order 02-1-38 Specified and Alternate Grade Fuel for Aircraft Engine Combinations dated Sept 1945

Here is an engine Torque Pressure Indicator

evidence of manufacturing year of 1948 for a USAF order

Theory of Flight, Technical Manual, TM 1-400 Feb 1941 F-84 This D-7 was made byThis authentic WWII era Theory of Flight Technical Manual contains the information necessary for pilot training when published in Feb 1941. It is 182 pages and in very good condition for its age.