Originally Posted by
infrequentwings
Speculating here, but I've a hunch that the distinction between the SFO flights for instance is that this flight might take of at a time when, in UK local time you would effectively have had two BA008 flights operating on the same calendar day.
Makes perfect sense though I did see two Cathay flights airborne last week with same flight no and callsign, albeit on a different leg of a multi-leg flight(!)