I am also on the topic of temperature corrections.
How do you correct for it during a VNAV approach(B737NG)? According to Boeing you shouldnīt 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(canīt recall the value) and I anyway donīt know if that is only for descent planning anyway.
Anyone in the know? Meanwhile I am back to good old V/S.
Regards, the Walter