Definition
Streamlined steel wires or cables on a biplane that run from the lower wing root upward and outward to the outer end of the upper wing, carrying the flight loads of the wings (the upward lift force) and transferring them into the fuselage structure.
Plain English
On a biplane, these are the wires running from the bottom of the fuselage up to the tip of the upper wing. When the wings are producing lift in flight, these wires are pulled tight and hold the wings in place against that lifting force.
Context Anchor
Seen during preflight or maintenance on wire-braced aircraft, especially biplanes and some light or vintage airplanes.
Derivation
Named for what they carry: the lift load of the wings. They are the wires that take the strain when the wings are lifting the aircraft.
Why Pilots Care
Proper tension and condition of lift wires are essential to prevent wing distortion or structural failure in flight.
Intuition Check
Lift wires do not create lift. They are support wires that carry the loads caused by lift.
Example Sentence 1
During preflight on the Stearman, the instructor showed the student how to check each lift wire for proper tension and signs of corrosion.
Example Sentence 2
Damage to a lift wire required grounding the biplane until repairs were completed.