I found online the manual for the B-25H & I was reading about the top turret & what it can do. It seems to the best of my ability's that there is some things in the manual that don't match our top turret.


So first off the AHII B-25H top turret can't get -1 degree in the horizontal. It looks to be set at 0 degrees the best that I can tell.
Since the top turret can go below -1 degree it could shoot the back of the rear gunners compartment. So to stop this it had two methods of doing it,first off from the drawing below you can see the two deflectors on top of the aircraft behind the turret. Our AHII B-25H top turret seems to fire over these two deflectors & just over the rear gunners canopy because I think they are set at 0 degrees.

The second method was done with gun firing circuits that would cut off the guns when in danger of hitting parts of its own air frame.
Now I had to look the next word up.
empennage https://en.wikipedia.org/wiki/EmpennageWe do have a cut off circuit for shooting through the empennage of the B-25H with the top turret.
We are missing cut off circuits for the top turret and its firing arc through its propellers. Our AHII B-25H top turret can just shoot through these if any one attacks from an off center frontal attack.