Undercarriage—That part of an aeroplane beneath the fuselage or nacelle, and intended to support the aeroplane when at rest, and to absorb the shock of alighting.
Velocity—Rate of displacement; speed.
Volplane—A gliding descent.
Weight—Is a measure of the force of the Earth's attraction (gravity) upon a body. The standard unit of weight in this country is 1 lb., and is the force of the Earth's attraction on a piece of platinum called the standard pound, deposited with the Board of Trade in London. At the centre of the Earth a body will be attracted with equal force in every direction. It will therefore have no weight, though its mass is unchanged. Gravity, of which weight is a measure, decreases with increase of altitude.
Web (of a rib)—That vertical part of a rib which prevents it from bending upwards.
Warp, to—To distort a surface in order to vary its angle of incidence. To vary the angle of incidence of a controlling surface.
Wash—The disturbance of air produced by the flight of an aeroplane.
Wash-in—An increasing angle of incidence of a surface towards its wing-tip.
Wash-out—A decreasing angle of incidence of a surface towards its wing-tip.
Wing-tip—The right- or left-hand extremity of a surface.