Type of Aircraft structure
Truss
A type of structure made up of longitudinal beams and cross braces. Compression loads between the main beams are by rigid cross braces called compression struts: Tension loads are carried by stays, or wires, that go from one main beam to the other and cross between the compression struts.
Most fabric-covered wings are constructed with a Pratt truss. The are the main beams and the cross braces are the compression struts or compression ribs. The stays are the drag and antidrag wires. The drag wires run from the front spar inboard to the rear spar outboard, and oppose the drag forces that try to move the wing tips backward. The antidrag wire run from the rear spar inboard to the front spar outboard. They oppose the aerodynamic forces that try to move the wing tip forward.
The Warren truss is used for the fuselage of most steel tube and fabric aircraft. The main beams are the longerons and the cross braces are steel tube diagonals which carry both compression and tension loads.