TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 5031-43 B-47 This indicator

This indicator

The data plate is absent from this example

to red/white (stopped)

it was also used across other USN aircraft such as the TBM Avenger

TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 5031-43 B-47 This indicatorThis is an authentic original WWII era Cruising Computer Mark 1 A designed specifically for the US Navy's Grumman Torpedo Bomber TBF 1. The purpose of the calculator was to determine the range, in nautical miles, of the aircraft under various conditions of aircraft weight, head tail winds, fuel quantity on board, true air speed, altitude, and throttle and supercharger blower settings. The calculator is essentially a custom 3 panel slide rule