I made the mistake of using dT at 289K instead of calculating an average temperature. I've added the sample to my formulae book so I don't make this mistake again. It wasn't BristolGS, I'm glad you guys could help me out.
I found the formulae McGrath noted in the Jeppesen Met Manual so i guess they are included in the JAA syllabus?
Thanks again
Last edited by JBA; 3rd Mar 2008 at 16:05.