Definition
A rigid framework of structural members — typically arranged in triangular patterns — used to support loads across a span. In aircraft, a truss forms the internal skeleton of the fuselage or wing, with longitudinal members (longerons) and cross members joined to resist bending and twisting forces.
Plain English
A framework of beams or tubes joined together — usually in triangle shapes — that gives an aircraft its shape and strength. Older airplanes were built around a truss skeleton, often covered with fabric or thin metal.
Context Anchor
Seen in aircraft construction and airframe structure discussions, especially when learning about tube-and-fabric fuselages or internal support frames.
Derivation
From Old French 'trousse,' meaning a bundle or collection of things tied together. The engineering sense came from the idea of bundling structural members so they support each other — exactly what a truss does in an aircraft frame.
Why Pilots Care
Knowing whether an aircraft has a truss-type structure helps pilots understand inspection points, damage tolerance, and why certain repairs require specialized knowledge — particularly on tube-and-fabric aircraft still common in the training and backcountry fleets.
Analogy
A simple bridge made from triangles is a good picture of a truss. The triangles keep the frame from folding or twisting easily.
Intuition Check
Do not think of a truss as just any support or bracket. In aircraft structure, a truss is a connected framework designed to spread forces through several members.
Example Sentence 1
The Piper Cub uses a welded steel-tube truss fuselage covered in fabric.
Example Sentence 2
Engineers chose a truss design for the wing because it provided the needed rigidity at low weight.