Originally Posted by
sandringham1
So they were concerned enough about weight/range that they they left bags behind and yet the weight of the passengers/crew/baggage/catering that they did go with is based on an an estimate, or have I got this wrong?
Baggage is not an esitmate. In Phase 4/5 or ALP systems, the actual weight of baggage is known, the exact distribution is not as the individual bags are not recorded in the system by location - however, the newer Amadeus ALTEA FM system (which NZ use in conjunction with their old checkin system and which QF use, both the FM (Flight Management/Load Control) and CM (Customer Management) modules record the actual weight of bags by passenger and the actual weight of the bag where it is loaded. So, if they offloaded the bags and took note of the location/passenger name(s) which they would have had to do in order to satisfy AAA requirements then they knew precisely the weight of the bags offloaded and those that remained on board. Yes, catering is known to be an estimate but it's a pretty close estimate/standard weight based on sector, passenger load and what sort of food (i.e. weight) is carried. The passenger weights are by necessity, standard weights. Don't know about Air NZ but I know Qantas surveys these every few years and has fairly accurate standard weights based on leg and segment. It would be impractical to weigh passengers on every flight.
Cargo may be offloaded first but certain non passenger load, mail for instance, may be the last to be offloaded.