Given the apparent susceptibility of the AS350/5's cabin to 'falling off' at the slightest provocation (okay, well some provocation) and given that they are still being produced .. wouldn't it be possible for our friends in Marignane to install a couple of roof spars extending say from the engine deck (where perhaps the spar could be mounted) forward into the fabric (or underside) of the cabin roof and in the general vicinity depicted by the yellow stripe in the image below?
Good thinking!
The significant issues are gearbox intrusion into the back seat and errant rotor blade into the front.
Perhaps your roof member could be designed to deflect the blade? Massive forces involved though...
After looking at ways to integrate camera processing and monitors in the rear I came up with a concept of a carbon fibre framework that installs inside the cockpit like a roll cage.
Seats and electronic kit attach to the framework. You would lose one seat in the rear. Then I though that if the frame work extended to the front that it would aid survivability of front seat passengers. There is space between front seats and door for the frame work. Would be very expensive to develop.
It is a glaring design issue that the blade can bend down and chop off the top half of the cabin.
I'm not a stranger to the manufacture of F1 bodies, given a clean sheet... one could make a new cabin in composite as one piece. In a prang the entire ball could detach and (with luck) roll away from the noise, fuel and moving parts.
I reckon this is better than the latest composite designs that incorporate engine mounts fuel cell and tail boom into the passenger cell.
Whilst there is little choice the more we crow about poor crash worthiness the better... as demonstrated by R44 fuel cell situation.