I think seaplanes would be very usefull in the game.
+1

Seaplanes, flying boats, amphibious aircraft, what ever they are called...
It would be nice to have representations of these types in Aces High.
I could imagine PBYs available only from ports and serving in roles similar to the C47. Also, the Catalina did some anti-ship missions, so perhaps they could have a limited bombing role as well.
This is a bit of a stretch, but maybe you could pick up a downed pilot, to turn a captured into a rescued?
What else?