ISA at FL100 is -5C (if based on 2 degrees drop pr 1000 ft).
If the actual temp at FL100 is 2C, the deviation is actually ISA +7C.
The atmosphere at FL100 is 7C warmer than the standard atmosphere. Makes sense?
Every once and a while I like to virtually strap one of these on my back... woohooo.. I feel the need, the need for speed B)
Orbx FTX Norway and Aerosoft F16.