The cleaners said so and they know first. They told me we own our 747's
Minor point but the cleaners info might be out of date! I believe the rumour might have been true for the old Classics back in the day but certainly a lot of the 744s used to carry a nice shiney plate riveted to the flightdeck wall structure saying which bank ( often a Japanese one) was financing the airframe, though I guess there's a chance that arrangement has changed.
In any event whatever the truth of the above I do agree with the comments about CAP and (over) recruiting.
In BA
AFAIK the "summer season" usually kicks in when the clocks change...i.e. usually the last weekend in March..in any event .you can usually tell by the amount of deadheading in the lines....