Originally Posted by DFC
Are you comparing the altitude you plan to fly at (based on QNH) to the "Altitude" in the cruise tables which is based on 1013 / 29.92?
Also have you allowed for a non-standard temperature at that level?
If the actual conditions are different from standard atmosphere there will be a difference in planned and actual TAS.
As to what to do for range?
Actually, that really depends more on your groundspeed/fuelflow relationship thatn TAS/fuelflow relationship.
Regards,
DFC
I'm not sure what u're asking about the altitude, but the manual covers temperature deviations, which were factored.