Was curious, after entering the performance data I noticed the ISA Dev line is filled in automatically, so is it safe to assume it's calculating that for you? Or do you actually have to compute ISA Deviation and enter it on that line? Can't quite wrap my head around that one... any of you FMC/CDU masters fill me in? Thanks much!

Anyone?

Knowing PMDG, it is quite assumably that it does not fill in a random figure. you can check it. Go to EHAM and set OAT to 15C. The ISA DEV should be 0.

I think you should enter isa dev yourself Lj. Prodanovic

I think you should enter isa dev yourself Lj. Prodanovic

you can do, but it does fill it in automatically. the question was: Does It Calculate It itself? Not, Do I Have To Fill It In Myself. No because it does automatically. So of course if you want to be sure, calculate the ISA Deviation yourself.

From what has been said above, if you mean "after entering perf data", including crz level temp, then yes there will be a calc'ed ISA dev. You could probably go the other way around as well, enter a dev and the smart plane would come up with a temp. Not so hard to double check that. Might actually do that later.

you can do, but it does fill it in automatically. the question was: Does It Calculate It itself? Not, Do I Have To Fill It In Myself. No because it does automatically.So of course if you want to be sure, calculate the ISA Deviation yourself.

And round to nearest integer.... If you find a different number I would be very very very much surprised The FMC contains the analytical functions for standard day (not just for temperature and not just troposphere). NOTE : if you edit the ISA field you will see the T/C temperature change too.

Ok thanks all! I was making way more complicated than it had to be apparently :) I'll calculate it out and cross check next time, not that I have ANY doubt that it wouldn't match up, if anything I'd be the one screwing something up ha!