King-Post—A bracing strut; in an aeroplane, usually passing through a surface and attached to the main spar, and from the end or ends of which wires are taken to spar, surface, or other part of the construction in order to prevent distortion. When used in connection with a controlling surface, it usually performs the additional function of a lever, control cables connecting its ends with the pilot's control lever.
Lift—The vertical component of the reaction produced by the action of driving through the air a surface inclined upwards and towards its direction of motion.
Lift, Margin of—The height an aeroplane can gain in a given time and starting from a given altitude.
Lift-Drift Ratio—The proportion of lift to drift.
Loading—The weight carried by an aerofoil. Usually expressed in pounds per square foot of superficial area.
Longeron—The term usually applied to any long spar running length-ways of a fuselage.
Mass—The mass of a body is a measure of the quantity of material in it.
Momentum—The product of the mass and velocity of a body is known as “momentum.”
Monoplane—An aeroplane of which the main lifting surface consists of one surface or one pair of wings.
Multiplane—An aeroplane of which the main lifting surface consists of numerous surfaces or pairs of wings mounted one above the other.