As well as crash resistant seats, reinforced floor and FADEC management of the engines, the newly designed main gearbox is built and tested to run for at least 30min without oil. Eurocopter says that it has run it for nearly 1h with no deterioration. If the engines have a significant overspeed, the compressor blades are shed, but contained within the compartment.
The undercarriage, fuselage and cabin are energy absorbing, just like Eurocopter's Tiger attack helicopter. This once landed at high speed at night during a demonstration. Both occupants walked away unhurt. There is a huge amount of redundancy in the flight-control systems, although not yet a redundant tail rotor drive system. I flew the aircraft raw with the control/power systems switched off. It was not difficult, just a bit demanding on the biceps.
The main rotor flight controls have excellent redundancy so that even if all hydraulic power is lost, which is almost impossible, the aircraft can still be flown. In the event of a heavy landing or crash, the main gearbox will not enter the cabin, says Eurocopter. This has often caused many a fatality.