Look at the picture I posted a link to, the cannon doesn't swing to the side. It separates and the barrel flips up with the cockpit.
As to the cannon being blown off, just one more thing to go wrong. I think the russians tried to rig a system for a helicopter ejection system where the blades were blown off. It was scrapped because the timing was never right.
Was it scrapped. I was sure the Havoc and the Hokum used that system. I think it was actually the russians who did it first.
