pd2/Bunnygirl.
Bunnygirl.
As an ex-BA Dispatcher I'm well versed on the vagaries of the 737/400. A two class config with more Club class than economy, eg to JER coupled with little deadload and a RLDW inevitably meant ballast on standby. One way of overcoming this problem early was to extend the Club class seating leaving enough seats in the rear cabin for economy pax, but ballast was used quite frequently. Some IT carriers crammed up to 180 pax on their aircraft, 28" pitch, can you imagine it?
pd2.
You mention being asked to move from an overwing seat "on a 400+ tonnes aircraft." Incredible. Or did you mean a 140 tonnes? Ryanair 737/800s have the first 6 rows blocked when the load is light, so my son tells me, I've never flown with them. Whatever the reason you were asked to move you should have complied. On larger aircraft like the 747 with a high fuel load the tendency is for it to be nose heavy with as much as 9 degrees nose up on the trim, the c of g in flight moves aft as the centre tank fuel is burned off. Shorthaul flights are a different kettle of fish, if the only way to trim the aircraft is to move passengers that's the way it has to be. Moving your 80 kilos from overwing, ( no change in balance ) to a seat further aft, a positive movement may have been all that was required to trim the aircraft.