OK
The equation is as such:
16,000 - (16*4*-10) - ((1013-1003)*27) = 15,090
16,000 is the altitude
(16*4*-10) (16) is the flight level abbreviated to the first 1 or 2 digits. Multiply this by (4c). (4c for every 1,000ft). Multiply it by the ISA temp dev'n (-10), in this case at 16,000 the temp should be -10, but its -27.
Second part of the equation is 1013 as used for FL's, then adjust it for the actual QNH, 1003, and multiply it by the standard 27.
Use this formula for all these types of Q's.
Good luck
Last edited by Number Cruncher; 12th Oct 2005 at 15:47.