It might have been one of my books as I "rescued" the Victor image from some old Handley Page documents - so it was a copy of a paper copy, hence the poor quality. It's been re-used on the net and in books quite a few times since then.
The aircraft is captured rolling off the top of a LABS half loop. It is indeed a B1 - in fact the only Victor B1 to have carried slipper tanks under the wings.
Vulcans also flew LABS half loops and (as has been said), aircraft were barrel-rolled occasionally. The practise was stopped after only a few years at Farnborough, and eventually Avro were asked (by the RAF) not to roll the aircraft at any appearances, as RAF pilots were trying to perform the same manoeuvre, but with damaging results. As has been said, it had to be rolled carefully with positive-g applied throughout.
Half loops were performed for quite some time though, as part of the Vulcan's nuclear delivery profiles, but as far as I can determine, such manoeuvres had been abandoned by the end of the 1960s.
Last edited by WH904; 23rd Jul 2013 at 15:52.