Caygill Could someone share some light on the theoretical possibilities of a T7 reaching 45000 feet, as indicated by the Mal authorities.
This source claims the service ceiling being 43100ft Aerospaceweb.org | Aircraft Museum - Boeing 777
The service ceiling is not the performance limit.
At the approximate weight at the time the aircraft would be limited by thrust such that it could maintain about 40000ft with maximum cruise thrust. It could maintain a higher altitude with higher thrust if this is available or it could make a zoom climb to higher altitudes but not maintain.
I am of the opinion that @45000ft is possible but also consider that the height is derived from primary radar and is therefore subject to some error.