I believe that when the FAC of the bus uses the angle of attack, it can only determine where is the cg regarding on the trim used to maintain that AoA at a given PA. You must take into account that during the flight the cg changes also with the cabin crew moving with the catering. For the weight, it is also involved the thrust, the speed, and the perf fac. Is it not?
I have heard that the only moment to check the cg is at the lift off. When you introduce the cg at the pre flight, you calculate a trim for the TO run. Someone told me that this cg must correspond with the one that the ap uses during the 2 segment. I don’t know if that is true.
I have been searching for a perf table within the OM to check the cg in flight. The only reference I have seen is under abnormal procedures, not reliable speed indications. Sorry if I missed the translation.
I would like to know if using the correct weight to the flight means some benefit to the airline. I suspect it doesn’t. A Spanish mayor airline, several years ago used to count the pax within the plane to check total with the loadsheet given by the gate desk. As more than 70% figures didn’t match (because bad count of the gate desk or crew) delaying the flight, the airline nowadays accepts the loadsheet as counted only at the gate. Does BA and other mayor airlines count pax OB?
Good flights