Hi Brad, Welcome to the list.
    I'm a newbie here myself. I just chime in when I feel strongly about
something, as in this case. Fighting fires was something I sometimes I did
for a living.
    Yes you are correct about putting the aircraft into a dive to blow the
fire out. But you are dealing with AIR COLLED engines, so they have to have
large holes in the cowling to cool them in the first place. Several problems
I see with this, not much good if you are flying VFR at 2000ft under the
weather, or flying at 2000ft VFR under controlled airspace in a built up
area. Secondly, even if you did manage to put the fire out in a dive, how do
you prevent it from re-igniting when you level out. Not mentioning all the
inherent problems of diving earth bound at speeds excedeing the VNE.
    The point I'm making is this. The rotary is NOT air cooled, (directly
anyway)therefore we can take a different approach in designing the cowl. We
do not need a large volume of air blasting into the cowl, because the the
radiators can be set up so that they are ducted from the outside seperately.
Granted it is much harder to acheive in a pusher.
    The one thing you must remember about a fire in a confined area is this,
if you block the air from getting in, the fire WILL go out. With that in
mind we design our rotary powered aircraft. Everything is imposible until it
is achieved. Nothing is achived until it is attempted.
Michael Burke.