Wind shear.  A sudden, drastic shift in wind speed, direction, or both that may occur in the horizontal or vertical plane. 

Wing. A fabric skin with an aluminum frame that produces the lift necessary to support the WSC in flight; including the flight wires/control frame below and the ground wires/king post above. 

Wing keel.  The WSC structural component in the longitudinal center of the wing that connects the two leading edges together at the nose and connects the carriage to the wing. 

Wing loading. The amount of weight that a wing must support to provide lift. 

Wingspan.  The maximum distance from wingtip to wingtip. 

Wing twist.  A design feature of the WSC that reduces the angle of attack from the root to the tip. 

Wingtip vortices.  The rapidly rotating air that spills over an aircraft’s wings during flight. The intensity of the turbulence depends on the aircraft’s weight, speed, and configuration. It is also referred to as wake turbulence. Vortices from heavy aircraft may be extremely hazardous to small aircraft. 

World Aeronautical Charts (WAC).  A standard series of aeronautical charts covering land areas of the world at a size and scale convenient for navigation (1:1,000,000) by moderate speed aircraft. Topographic information includes cities and towns, principal roads, railroads, distinctive landmarks, drainage, and relief. Aeronautical information includes visual and radio aids to navigation, airports, airways, restricted areas, obstructions and other pertinent data. 

WSC.  See weight-shift control. 

Weight-Shift Control—Land (WSCL). WSC that takes off and lands on land. This can be wheels or ski equipped. 

Weight-Shift Control—Sea (WSCS). WSC that takes of the water. This can be pontoons or a boat configuration. 

Yaw. Rotation about the vertical axis of an aircraft. 

Zulu time. A term used in aviation for Coordinated Universal Time (UTC) which places the entire world on one time standard. 

