There's your info guys. BA did have 5 but now only have 3. Incidently because these are the A-versions, they have a more limited range than the B-versions (i.e. VII* and YMM*) so they tend to be used to on the short-medium haul routes like LHR-East Coast e.g. Boston, Newark and well as the Middle East.
Dnomyar19, I never knew that! Was the small cargo door a standard fit on the triples before they came up with a large aft door? Did BA decide to take advantage of this but VIIA was already in manufacturing before they could implement it? It seems strange that it is the oddball in the fleet.
Regards,
Champ