I think it is pretty clear in the picture that the APB is essentially one unit that encompasses above and below the floor, not two parts one above and one below the floor.
Inside the pie section labled "Damaged Bulkhead" on the picture you are looking through the APB at the backs of the galley cabnetry located on the forward side of the APB. The bottom of the white structure is the floor level (cabin/baggage seperation). This is a massive breach of the APB. Closing the two outflow valves with the "Ditch Switch" would have made little or no difference in keeping water out of the cabin.
C2j
Last edited by Cubs2jets; 1st Apr 2012 at 18:19.
Reason: Clarity and edification