Aviation Maintenance Terms beginning with W

Warp clock

An alignment indicator included in a structural repair manual to show the orientation of the piles of a composite material. The ply direction is shown in relation to a reference direction.

Warp threads

Threads that run the length of the roll of fabric, parallel to the selvage edge. Warp threads are often stronger than fill threads.

Warp tracers

Threads of a different color from the warp threads that are woven into a material to identify the direction of the warp threads.

Wash in

A twist in an airplane wing that increases its angle of incidence near the tip.

Wash out

A twist in an airplane wing that decreases its angle of incidence near the tip.

Watt

The basic unit of electrical power. One watt is equal to 1⁄746 horsepower.

Way point

A phantom location created in certain electronic navigation systems by measuring direction and distance from a VORTAC station or by latitude and longitude coordinates from Loran or GPS.

Web of a spar

The part of a spar between the caps.

Weft threads

See fill threads.

Wet-type vacuum pump

An engine-driven air pump that uses steel vanes. These pumps are lubricated by engine oil drawn in through holes in the pump base. The oil passes through the pump and is exhausted with the air. Wet-type pumps must have oil separators in their discharge line to trap the oil and return it to the engine crankcase.

Wing fences

Vertical vanes that extend chordwise across the upper surface of an airplane wing to prevent spanwise airflow.

Wing heavy

An out-of-trim flight condition in which an airplane flies hands off, with one wing low.

Wire bundle

A compact group of electrical wires held together with special wrapping devices or with waxed string. These bundles are secured to the aircraft structure with special clamps.

Woof threads