Weathervane effect

From Wikipedia, the free encyclopedia

Weathervaning or weathercocking [1] is a phenomenon experienced by aircraft on the ground and rotorcraft on the ground and when hovering.

Aircraft on the ground have a natural pivoting point on a plane through the main landing gear contact points [disregarding the effects of toe in/toe out of the main gear]. As most of the side area of an aircraft will typically be behind this pivoting point, any crosswind will create a yawing moment tending to turn the nose of the aircraft into the wind.[2][3]

It is not to be confused with directional stability, as experienced by aircraft in flight.[4]

The term also refers to a similar phenomenon in fin-guided small rockets which, when launched vertically, will tend to turn into a flight path that takes them upwind.[5]

See also[edit]

References[edit]

  1. ^ Heflin, Woodford A. (Ed., 1956). The United States Air Force dictionary. Princeton, NJ: D. Van Nostranc Co. Inc.
  2. ^ Denker, John S. (n.d.). See how it flies. Retrieved March 22nd from http://www.av8n.com/how/.
  3. ^ FAA (2004). Airplane Flying Handbook. Washington D.C.:U.S. Department of Transportation, Federal Aviation Administration, FAA-8083-3A.
  4. ^ Anderson, John D. (1989). Introduction to flight (3rd ed.). New York: McGraw-Hill Book Company.
  5. ^ Benson, Tom. "Weather Cocking". National Aeronautics and Space Administration Glenn Research Center.