cisaillement de vent

CONT: Le cisaillement de vent est particulièrement dangereux pour les [avions] au décollage et à l'atterrissage, car il peut, en provoquant de grandes variations de vitesse relative et de vitesse verticale, projeter l'appareil au sol.
OBS: Ce phénomène peut se produire sur le plan vertical ou horizontal et quelquefois sur les deux.

CONT: Most winds travel horizontally, as does most wind shear, but under certain conditions, including thunderstorms and strong frontal systems, wind shear will travel in a vertical direction. Microburst wind shear ... can cause an aircraft to lose lift and crash, especially during takeoff or landing, when the slower speeds and closeness to the ground make altitude correction more difficult. Since 1996 all U.S. airliners have been required to be equipped with instruments that provide the pilot with advance warning of wind shear.
OBS: wind shear. ... Shear usually refers to vertical wind shear (i.e., the change in wind with height) but the term also is used in Doppler radar meteorology to describe changes in radial velocity over short horizontal distances. Moderate to strong wind shear is required for supercell development.

OBS: cizalladura del viento; WS: término y abreviatura aceptados oficialmente por la Organización de Aviación Civil Internacional (OACI).