Oh no, they CAN hit you with both bombs and bullets. But they are not as big a threat to the U-boat as they are in the supermods this is what I found when transitioning to GWX 1.01, mainly because the bullets do nothing to you, and U-boat hulls were not built to withstand direct gunfire from heavy machine guns which you find mounted on planes.
So all Im saying is that Planes in stock are not as threatening as they should be.