Flight—The sustenance of a body heavier than air by means of its action upon the air.
Foot-pound—A measure of work representing the weight of 1 lb. raised 1 foot.
Fairing—Usually made of thin sheet aluminum, wood, or a light construction of wood and fabric; and bent round detrimental surface in order to give it a “fair” or “stream-like” shape.
Gravity—Is the force of the Earth's attraction upon a body. It decreases with increase of distance from the Earth. See “Weight.”
Gravity, Specific—Density of substance Density of water. Thus, if the density of water is 10 lb. per unit volume, the same unit volume of petrol, if weighing 7 lb., would be said to have a specific gravity of 7/10, i.e., 0.7.
Gap (of an aeroplane)—The distance between the upper and lower surfaces of a biplane. In a triplane or multiplane, the distance between a surface and the one first above it.
Gap, Propeller—The distance, measured in the direction of the thrust, between the spiral courses of the blades.
Girder—A structure designed to resist bending, and to combine lightness and strength.
Gyroscope—A heavy circular wheel revolving at high speed, the effect of which is a tendency to maintain its plane of rotation against disturbing forces.
Hangar—An aeroplane shed.