CGI as expected, with studio mockups for the interior shots. The aircraft scenes don't look too bad all things considered..certainly no worse than a lot of the old school model shots in older films. A little strange that they used a single open tail gun setup like "Diamond Lil" when the aircraft is supposed to be a B-24D, but I suppose getting ahold of a Consolidated A6 turret is next to impossible, especially for just a few brief scenes. The interior mockups look a little simplified, but good enough for movie purposes (and my Inner Model Geak can't help but notice they got the interior colors wrong.) Considering the B-24 sequences are a fairly small part of the overall movie, I give them kudos for making the effort rather than using B-17 or B-25 as a stand-in. This one is definitely on my "must see" list.
SN
http://www.youtube.com/watch?v=X8mBzKLhL0U