The complete central structures of aircraft, to which the wings, tail assemblies, and engines may be attached. In the early 20th century, the term was taken from French specifically to refer to the framework of the body of an airplane, particularly the girder-like backbone employed in airplane design; it has since come to mean the entire central structure of the aircraft.Wordt gebruikt voor de gehele centrale constructie van luchtvaartuigen, waaraan de vleugels, staartassemblages en motoren kunnen worden bevestigd.航空器的完整中央結構，可以裝載機翼、機尾裝配組件和引擎。