air pocket(redirected from Vertical draft)
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Related to Vertical draft: updrafts
a localized region of low air density or a descending air current, causing an aircraft to suffer an abrupt decrease in height
air pocket[′er ‚päk·ət]
An air-filled space that is normally occupied by a liquid. Also known as air trap.
An expression used in the early days of aviation for a downdraft; such downdrafts were thought to be pockets in which there was insufficient air to support the plane.
An air-filled volume within a section of piping (or an apparatus) which is normally filled with liquid.
An area of reduced pressure in the air in which the aircraft looses height rapidly and creates an illusion of absence of air to support the aircraft. The resultant effect is rather unpleasant. An air pocket can also produce the reverse effect, but the experience is not as unpleasant.