System for calculating flying time in minutes with a given speed over ground of an aircraft on a map with one of a given number of scales, whereby a simple arrangement allows calculation taking into account expected wind speed

摘要

System for calculating flying time in minutes in relation to a map scale comprises two diagrams for the provisional graduation of erasable sliders of a slide rule for calculation of time of flight at a specific speed over the ground. Each diagram has one or two map scales out of 1:100,000, 1:200,000, 1:250,000 and 1:500,000 and our marked using a pen for marking on plastic.