John Hill:
how were the crew ever able to get the aircraft back on a level attitude, which it was at the time of impact?
Not withstanding any possible effects of control and / or thrust inputs buy the pilots... when the aircraft rolled (to the right) and then slid sideways out of the sky, it's possible (probable?) that the sweep of the downward going wing would most likely cause that wing to generate lift (remembering that it's a very big wing, with a lot of sweep) and which... referencing my copy of D.P.Davies 'Handling The Big Jets' (3rd edition)... is a phenomenon that's more properly known as 'an increase in the projected span'.
Conversely, the wing on the other side would generate no lift and therein the asymmetric lift between the two wings would cause the aircraft to roll (in this case to what just happened to be an almost level attitude prior to it impacting the ground).