Is it true Britannia chose the B767 over the A310 because it could make FL370 by the UK FIR boundary off Luton and miss a shed load of slot restrictions?
No idea about why the 767 was chosen, but I remember the policy when tanking fuel we'd only tanker so that we could still make FL410 direct. Tanking to a Take-off weight of 121 500kgs rings a bell, but if that was figure used, you've witnessed a miracle, as my memory is unreliable!