Hi,
Here's a crude method I use which works well and can prevent a gross error.
1. On a chart draw your route.
2. Mark the airfields in question with a large dark coloured blob of ink.
3. Hold the chart up to the light, fold it in 2, so that the two blobs are superimposed.
4. Make a crease in the chart in this posn.
5. Unfold the chart.
In still air, the crit point is where the crease intersects your route.
You can allow for the wind by shifting the crease upwind.
Sounds complicated but after a little practice it is quick and easy.
Regards
[This message has been edited by invalid entry (edited 29 November 2000).]