Originally Posted by
peterh337
Sure, but why would you need to calculate the "exact" wind while flying?
All that matters when flying (for fuel endurance, ETA, etc) is the ground speed, and if you are expecting that to be significantly affected by the wind during your flight then the wind direction etc are also likely to be changing.
Exactly. The huge value in using the GPS is a continuously updated real time ETE. The only winds that matter are the winds you are experiencing, which in the low levels are unlikely to be exactly as forecast.
For a longer cross country I always do an inflight wind calculation because if the wind is very different then what was forecast you can take all your preflight met printouts crumple them into a ball and throw them into the back of the airplane. It is now time get new weather and to start coming up with a plan B