Weighting passengers saves fuel?
For a long time we've been weighting passengers' baggage, but not actually themselves. Generally accepted 'weight' of a passenger is 75 kgs in summer period and 80 in winter. These are mean averages, derived from some kind of statistical research I guess. But inevitably actual weights of passengers are different (smaller). 75 and 80 kgs looks like very conservative figures. What if each passenger will be weighted at registration deck, thus actual weight of payload can be obtained and therefore fuel requirements for a flight can be calculated based on more precise input data (precise payload weight I mean). Also, %CG can be calculated more accurately, as well as takeoff speeds.
What is your opinion on this?