Fuel Economy in Flight

Extract

Fuel consumption in flight is dependent on three main factors—the aerodynamic efficiency of the aeroplane, the thermal efficiency of the engine, and the efficiency of navigation, which entails a study of the most advantageous height, speed and direction of flight under any conditions of wind. Fuel consumption is therefore the ultimate measure of the overall efficiency of the complete aeroplane, the pilot, and the organisation ; its complete study would require far more time than can be given to it in a single lecture. I propose, therefore, to confine myself to fairly general considerations, with particular reference to the commercial aeroplane. There have been distinct advances in the direction of fuel economy in flight since the war period, but even now the weight of fuel carried in a commercial machine operating over the comparatively short London-Paris route of 230 miles and capable of a cruising speed of 100 miles per hour is approximately half the full paying load carried, so that a reduction of the fuel load by 40 per cent., which is by no means outside the range of possibilities, would increase the paying load by 20 per cent., other things being equal.