ATPL flight planning question
Hey guys, just a quick question (not too complicated), I was just wondering if when using the TAS equation (True mach no. x 39 x square root of true temp+273) you should use 38.975 or 39 (for simplicity) in the equation??
I know its not much difference at all but Ive done a few calcs and found the TAS to be 1-2 knots different when using 39 or 38.975 which got me wondering if I used one or the other in a 5 mark question it would alter the answer enough to get two different answers in the CASA exam (I dont know how spaced each answer is).
What did you guys use??
thanks