Downwash is the name for a wind that moves from the standpoint of the observer. There is, for example, in a region predominantly westerly winds and the residential patterns Walde is located east of the industrial system XYZ, then you can say that the residential pattern of the forest lies downwind of the industrial system XYZ.
Similarly, downslope winds are winds that move on a slope down away from the slope.
The English name called downwash in aeronautical engineering also a technical downdraft, as generated by aircraft and helicopters. For helicopters that is generated by the rotating rotor blades and is very clearly perceptible to the environment during takeoff and landing. For aircraft, this air flow is not perceived in direction of the ground because of the need for rapid forward movement usually on the ground or a stay on the runway of an aircraft is not practical for safety for humans. When whiz other hand, looks a nozzle down that creates the downwash. From the downdraft a counter pulse, which ensures that each aircraft can rise from the ground and stays in the air creates.
The technical term also appeared in racing. So it was for the Formula 1 rules from 2008 in conversation to introduce a " CDG wing " (English " Centerline downwash Generating wing", downdraft producing central axis wing). Thus, the slipstream should be improved for the subsequent transport to produce more overtaking maneuvers or, which is more tension in the race. However, this development was not used.