Plain English Meaning

The long backbone-like rods or beams that run nose-to-tail along an aircraft's body, forming the main framework that everything else is built around.

Full Definition

The main lengthwise structural members that run the full length of an aircraft fuselage in a truss-type structure, carrying the primary bending and tension loads. Longerons are connected by vertical and diagonal cross-members (and often by wire bracing) to form the rigid skeleton of the fuselage.

Context Anchor

Seen in aircraft structure descriptions, especially when studying truss-type fuselages and how the aircraft body is built.

Derivation

From the French 'longeron,' meaning a long beam or girder, itself rooted in 'long.' The name simply marks them as the long members of the structure, distinguishing them from the shorter cross-pieces.