WIND

A topic seldom discussed among soaring pilots is change in wind direction and strength.   It can happen very abruptly as we move from one point to another or as we change altitudes, and can occur suddenly in one place, too.   Whatever else you’re doing in flight, check often to see if the ambient wind is different in any way.   When it’s hard to be sure, hold straight and level and then look directly ahead as well as straight down both sides of the cockpit to determine your direction of drift.   If you happen to be circling in lift, look straight down the inside of your turn to observe drift.   Sudden changes in degree of turbulence or smoothness also might indicate that a change in wind is occurring.   The sharper such a change is, the more it’s apt to bring either lift or sink (or increases in both) – each of which might be difficult to understand if the wind shift goes unnoticed.   Although a clever soaring pilot can often find valuable opportunities associated with changes in wind, some challenges may also arise. One way in which strong wind can affect your fortunes aloft is the detrimental effect it can have on thermals.   Wind could sweep the air away from thermal sources before they have time to transfer sufficient heat to the air, or it may break existing thermals into rolling balls of turbulence too small to use.Strong wind also seems to elongate thermals that do rise, combing them into street-like rows parallel with the wind direction.   Individual thermals may be very narrow and short-lived in such conditions, and therefore difficult to use down low.   Even so, if you can maintain something above median height the lift may still be workable.   When thermaling in strong wind it helps to flatten your bank on the windward side of turns and steepen it on the downwind side, like a power pilot doing ‘turns-around-a-point’.