Take some youngsters from 1980's and put them into World War two bomber and call the result as a "realistic war movie". Even if we exclude the fact that no detail presented in "Memphis Belle" movie pertain to actual events, the general level of knowledge about World War Two matters is better to be set into minimum before you proceed to watch this. This film is not about World War Two, it is how we can talk about it without caring to know anything at first.
For those who have seen other war movies it is better to give a warning about the terrible anachronisms what this film will throw at your eyes and ears. The storyline is just superficial and it is not really a World War Two story even if there shouldn't have been problems in making it look like that. The bomber crew in itself is a terrible platitude with a mentality that does not represent a veteran crew on their last bombing mission.
Once you have a change to use authentic bombers and other vintage aircraft you should have done it properly and not this strange Disney impersonation of war. For those who look for more dedicated air combat movie I'd recommend Twelve O'Clock High.