In today's update, Loft tells us more about how the gameplay works in BoS, and it seems they have decided to really take into account what REALLY transpired at the Battle of Stalingrad. By the looks of it, historical accuracy seems to be really important in the Historical Campaign; correct squadrons, aerodromes, plane types, mission types.... even the weather!!
"Weather is taken into account as well. We've preset certain rules for weather in every phase. For instance, some periods will have pretty bad weather simply because that's how it was in real life according to history. Wind speed and direction is taken into account as well. The time when the mission starts will be set depending on the specific regiment you're playing for and the period of the phase."
Please, have a read at il2sturmovik.net
He also gave us this little gem:
HAPPYY MIDSUMMER all SVAFfers and friends!