We can easily see now how significant the effect of the headwind or tailwind is. The performance penalty for being downwind of the airfield on a local flight is significant, as is the reward for being upwind. So what effect has lift and sink on these matters? A more experienced glider pilot might derate the glide performance of their glider by about 80 per cent to account for the vagaries of sink to maintain a good margin of safety. Rather than get involved in the disappointing performance into headwinds, the same pilot would find it more profitable to stay upwind of the airfield on local flights. For the newly
solo pilot the rules should be quite a bit more restrictive. The glide ratio should be derated by 50 per cent. In our example, this would mean assuming a glide ratio of 15 and thus staying within 2.5 nm upwind of the airport on a 2000 foot aerotow regardless of the strength of the wind.
In addition to this restriction, assuming soaring cloudbases of 5000 AGL, pilots at this level of experience should not wander any further 5 nm away from the field, regardless of the altitude they might soar to. The primary reason for this is the possibility of the pilot losing their orientation to the airfield. It takes some time and practise to build up map reading and orientation skills. This may seem like a simplistic approach to glider performance but reflects the level the newly solo pilot should be expected to perform at. When the pilot has gained some more experience they can progress to the local soaring mode (pre cross-country) where other exercises and tactics are appropriate.