Downwash

Downwash
The effect of downwash from a hovering helicopter is clearly visible on the surface of water below.

In aeronautics downwash is the air forced down by the aerodynamic action of a wing or helicopter rotor blade in motion, as part of the process of producing lift.^[1]

An aircraft produces aerodynamic lift by deflecting air downwards as downwash. This generates an equal and opposite upwards force on the wing called lift. When the downwash force exceeds the weight of the aircraft, the aircraft will rise.^[1][2][3]

See also

• Slipstream
• Wake turbulence
• Wingtip vortices

References

1. ^ ^{a b} Crane, Dale: Dictionary of Aeronautical Terms, third edition, page 172. Aviation Supplies & Academics, 1997. ISBN 1-56027-287-2
2. ^ Anderson, John D. (2004), Introduction to Flight (5th ed.), McGraw-Hill, pp. 352–361, §5.19, ISBN 0-07-282569-3 
3. ^ "The main fact of all heaver-than-air flight is this: the wing keeps the airplane up by pushing the air down." In: Langewiesche, Wolfgang (1990), Stick and Rudder: An Explanation of the Art of Flying, McGraw-Hill, pp. 6–10, ISBN 0070362408