Originally Posted by
AerocatS2A
We didn't do it until we got the H3 upgrade. Now we do it because the ground temperature input affects climb performance predictions. I suspect it probably doesn't matter much whether you enter the OAT or ATIS temperature as they'd be close enough not to make much difference.
Thanks for this. Switched recently to a company with Thales FMS software from a Honeywell one and the information in the FCOM about the use of this was pretty much non existent .