TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 4785-43 He-111 as well as a close-up

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

where he was base commander

A few pages have a sometext with highlight marks

and ~4 inches tall

TBF-1 Avenger Torpedo Bomber Cruising Calculator Mark 1-A, Ser # 4785-43 He-111 as well as a close-upThis 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