TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 4785-43 He-111 where he was base commander

where he was base commander

All have damaged or missing glass and some missing pointers

The C-13 Altimeter was used across all aircraft of the Air Corps US Army

as well as a close-up of an illustration from a B-25G technical manual

but the fluid in the rear chamber is absent and there is a slight internal rattle

TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 4785-43 He-111 where he was base commanderThis 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