Finding Wind Movement at a Confined Area.

Many student helicopter pilots become frustrated when faced with the seemingly daunting task of determining wind direction at an off airport landing site. When the wind is evident but the direction not obvious there are several ways to “see” the wind.

• Wind motion on trees and water in the area will display the wind movement. Learning to read the direction of wind from these cues is a matter of practice and comparison with other signs of the wind for confirmation.


• Some pilots like the “18 in. MP / 45 mph” constant attitude technique in a turn over the area to show the wind drift. Hold the collective at a power setting of 18 inches which should result in an airspeed of 45 mph if you hold the attitude constant in the turn. The helicopter will drift downwind in a significant wind.


• If you just cannot seem to “find” the wind, look for the best two approaches from opposite directions and try each one at a high enough power setting to support the weight of the helicopter just at the point of translation speed where the lift from forward flight is beginning to have a buoyant effect. The speed or motion of the helicopter at this point will be slow and will not register on the airspeed indicator (which you shouldn’t be looking at anyway!) but will be in the range of 5 to 8 knots. The approach that has the higher power setting is the one that is downwind. An instructor will have to demonstrate this technique to you first because too often student pilots will try this technique incorrectly and get a false sense of wind direction.


• Remember that once you have found the wind direction, the best approach must be given equal billing. Too often students will find the wind direction and then approach only from this direction even if there is no approach opening on this side. The wind direction has a splay to it and as long as you are within 50° to 60° on either side you will be getting the benefit of being “into wind”. This will give you an opportunity to find the best approach into the enclosed area. Many times I have seen students attempt an approach perpendicular to a long narrow entrance to an area because it is into wind. Give wind direction and the best approach equal consideration knowing that being “into wind” has some flexibility.