120-1 “FLY TO USE LESS FUEL”. This booklet gives a simple method of determining the important critical working speeds of any propeller powered aircraft. These speeds are not given in the pilot’s aircraft manuals. It explains the working speeds of the aircraft in simple to understand graphics, no complicated mathematical formulas used. And what’s even better there’s no need to do a time consuming flight test program to determine the working speeds of your aircraft. This booklet gives simple multiplication factors, based on cruising speed of the aircraft, to determine the critical working speeds of your aircraft. For example when low on fuel what speed should the aircraft be flown to get the most miles ...