Definition
A structural wire in a wing or truss-type airframe that runs diagonally from the front spar to the rear spar and resists rearward (drag) forces acting on the wing in flight. It works in opposition to the antidrag wire, which resists forward forces.
Plain English
A wire inside the wing that holds it firm against the backward push of the air as the aircraft flies forward.
Context Anchor
Seen in airframe maintenance, especially on older fabric-covered or wire-braced aircraft when inspecting wing structure and internal bracing.
Derivation
Drag here is the aerodynamic force pulling rearward on the wing as the aircraft moves through the air. The wire is named for the force it resists, not for any dragging action of its own.
Why Pilots Care
Maintains wing alignment and structural rigidity; loose or failed drag wires can allow the wing to distort under load and change handling qualities.
Intuition Check
Do not read “drag wire” as a loose wire that creates drag. It is a structural brace named for the backward aerodynamic force it helps resist.
Example Sentence 1
During the wing inspection, the technician checked the tension of each drag wire and antidrag wire.
Example Sentence 2
During flight, properly rigged drag wires prevent the wing from shifting aft under aerodynamic load.