Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 such as the P-40

such as the P-40

B-50 Superfortress

The fluid is low by about a 1/2 teaspoon

000 ft to align with the line markings outside of the window

type AN-5825-7

Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 such as the P-40Here is a WWII era Chronometric Tachometer Disk Speed Indicator Kit, made by Technical Oil Tool Co. (TOTCO), used by bombardiers and technicians to check the proper operation of the Norden Bombsight The kit contains the disk speed indicator, two tachometer tips, instructions, and a metal case with a rubber lined compartment. It is in very good condition given its age. The case measures ~4. 5 inches long, 3 inches wide, and ~1. 5 inches deep.