Luscombe Driver,
The magic formula and factors devised by Dr. J. Bellamy, Chicago give the net drift , in nautical miles:
(P1-P2)*K /TAS
Where;
P1= Pressure at Departure
P2= Pressure at Destination
K = Factor for average latitude between departure and arrival points.
TAS = True airspeed (knots).
Latitude - K Factor
22-25 - 540
25-28 - 480
28-31 - 440
31-34 - 400
34-38 - 360
38-43 - 330
43-50 - 300
50-55 - 270
(P2-P1)is positive= Left drift
(P2-P1)is negative= Right drift
When you have the net drift worked out,use flight computer (E6-B or whatever!)to figure out the drift angle. True heading + magnetic variation +/- drift angle gives single-heading to fly the route. As you probably know already, this is useless for flights at 2000" AGL or less, due to surface friction.
I’ve used this for fun, and found it to be no more than 1 or 2 miles off on trips of about 200 nm!
Hope that helps!
[This message has been edited by NIMBUS (edited 16 September 2000).]