Air Pocket—A local movement or condition of the air causing an aeroplane to drop or lose its correct attitude.
Aspect-Ratio—The proportion of span to chord of a surface.
Air-Screw (Propeller)—A surface so shaped that its rotation about an axis produces a force (thrust) in the direction of its axis. [2]
Aileron—A controlling surface, usually situated at the wing-tip, the operation of which turns an aeroplane about its longitudinal axis; causes an aeroplane to tilt sideways. [3]
Aviation—The art of driving an aeroplane.
Aviator—The driver of an aeroplane.
Barograph—A recording barometer, the charts of which can be calibrated for showing air density or height.
Barometer—An instrument used for indicating the density of air.
Bank, to—To turn an aeroplane about its longitudinal axis (to tilt sideways) when turning to left or right.
Biplane—An aeroplane of which the main lifting surface consists of a surface or pair of wings mounted above another surface or pair of wings.