ok ok ok.
Lets clear this up.
Thanks for all the advise re calculation, I have to point out that I am well able to do all the calc necessary in me noggin, on the ground and in the air if necessary ( as noggin points out - the met man is not the most acurate being around. )
This mental working will be as correct as any PPL will need nearly always. My situation though is this.
1. I am tight - I know there are packages you can buy, but I am intending to make my own.
2. I'm Lazy - Whenever I fly, unless I am sure of the visual route - I will draw my lines, measure my distances, angles and such and write it all in my plog. Then before the flight look at the WX and, as you say, mentally add a correction - that I know will be within a degree or so - write it in, then do the time. Ok so far? Pretty standard stuff. It's just that when I get home I throw it all away and forget about it. So the jist is that I intend to type all the details into a plog once, and keep em to use again. (Just having to change the wind speed and direction every time I fly that route - everything else is either already there or recalculated for me ) Saves me time is all. The drawing lines bit is the fast bit - and as you say noggin, I also aviod the wheel if I can.
Soooo, the initial post was along the lines of, if I am going to do a plog program, it might as well caluclate the CORRECT variation for me and do all the groudspeed EXACTLY. The Trig. Calc's for these problems I didn't know - read couldn't be bothered ( ref. Lazy ) - and thought someone might well have already done the graft - enter tacpot - many thanks by the way tacpot.
Hope this clears it all up, and again thanks for all reposnses.
Im off to sunny Blackpool now to scare some clouds - happy flying.
LF
ps. Still after the groundspeed trig.!! Anyone?
[ 18 November 2001: Message edited by: long final ]