Cabin door is locked during firing, as the light would blind the eyes of the operators.
In the dark, they could see more detail on the scopes, just like the submariners...
Hpasp Free SAM Simulator, "Realistic to the Switch" (U-2 over Sverdlovsk, B-52's over Hanoi, F-4 Phantoms over the Sinai, F-16's and the F-117A Stealth bomber over the Balkans.) http://sites.google.com/site/samsimulator1972/home