In response to IO540, BEagle wrote:
Originally Posted by BEagle
Your figures are generally about 17% in error.
Perhaps good enough for the playstation generation of button pushers; others set themselves higher standards by correct application of the max drift technique.
Hmm ...
Applying the rule of thumb figures you advocate, BEagle, for a TAS of 90 kts and a Wind Velocity of 30kt at 15 deg off, the drift correction to be applied is 2/3 x 1/4 of the wind speed = 5 deg.
But the true drift correction is 7.3 deg.
So your rule of thumb would be in error by 31.5%, BEagle, nearly twice the shock horror error you observed in IO540's figures. Perhaps in future you should fly with a set of trigonometry tables!
It isn't, however, your rule of thumb I'm quibbling with. That's the one I was taught, and it works perfectly satisfactorily.