+1 - I too just tend to dive when an air contact is picked up, and live to fight on. It just takes one well placed, or lucky hit, bomb to really ruin a submariners day
I just see it as my job to put torpedoes into ships - which in itself entails enough risk of my crew and boat - I don't need to risk a whole submarine and crew over an aircraft or two (I'd much rather find a full carrier's worth of planes, and put that on the bottom! - that's worth taking some risk over).