Aircraft Instruments Technical Instructions, Air Corps Technical School, 1939 C-130 Measures 4 inches diameter and

Measures 4 inches diameter and ~11 inches deep

and the knob rotates

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

The fluid is discolored and about 2/3rds level

Kollsman FSSC number 88-C-855 was made for aircraft of the US Navy

Aircraft Instruments Technical Instructions, Air Corps Technical School, 1939 C-130 Measures 4 inches diameter andHere is a pre WWII era Technical Instruction reference manual for students of the Air Corps Technical School, published in October 1939, for use in training aircraft instrument technicians of the US Army Air Corps. This 258 page, 8. 5 by 11 inch technical manual covers all of the most commonly used instruments used in aircraft of the era, including pressure, temperature, and quantity gauges, compasses, turn, climb, and airspeed indicators, gyro