Nick, i wouldn't describe the accident as a "sudden rotor stoppage". A sheet from the building damaged the blades at 100%. There are radial forces up to 12 tons on the blades of a BK 117 at 100%. The now working unbalance after the sheet struck, ripped off the MGB from the deck in a few seconds. The MGB was found 6m away. Parts of the blades still connected to the MR hub. Thats a scenario i'm sure you have seen during ground test some times. I believe there is a sikorsky video junking a chinook during ground test. I'm not sure if the much more modern and new designed ships are able to keep up such a situation. Indeed i believe not. On such forces it isn't possible to construct a more safe system. Also the AH 64, much more though designed encountered problems with this scenario.
This was an older BK 117 designed more than 20 years ago. But i want to mention the cabin area including cockpit is absolutely undamaged. The tail boom is still on the frame and not bended, only the rear crosstube is broken. I don't think the a/c is to much damaged linked to such a scenario. Ok, sure the deck and the frame are bended, it's a million damage at least. All the guys walked away, only the doc is injured because he doesn't weared his helmet and striked his head. I believe it's better to stay on the ground with a naked MGB deck and a broken crosstube, than to find the MGB coming through the deck inbound the crew. I think this accident have shown the BK 117 as a well designed and rough a/c.
And to the questions about the EC 145. The EC 145 is a BK 117C2. But the new cabin strengthened due to the use of carbon fibres withstands higher breaking loads.
Last edited by tecpilot; 17th Dec 2005 at 09:15.