Cold Temperature and VNAV approaches
Whilst I was reading the OM check thread I started wondering about the temperature corrections during a VNAV approach.
How do you correct for it during a VNAV approach(B737NG)? According to Boeing you shouldn´t alter anything from FAF onwards because you are messing up the programmed approach logic, except as stated in FCTM 5.36 “... crews should make cold temperature altitude corrections by applying a correction from an approved table to the waypoint altitude constraints.”
So what should we do?
Use the descent forcast page?
Change values from FAF onwards?
I am quite sure the isa dev on the descent forcast page allows only for a rather high temperature(can´t recall the value) and I think it is for descent planning only.
Anyone in the know? Meanwhile I am back to good old V/S.
Regards, the Walter