The most sensible solution is a better seat design. It does not matter if you wreck the helicopter in the crash, it matters that the crew survives. So you woant adsopring structure, airbags and special seats that deform to keep the nergy away from the passenger.

Seat design is important but can only absorb the crash energy in the vertical axis, so if the helicopter doesn’t crash on the level the seat won’t do much good. Also without airbags the airframe has to absorb all the crash energy which will probably result in the crew getting crushed or trapped as happens in car accidents.

See the airbag pics here
http://www.rafael.co.il/web/rafnew/products/brochures/REAPS.pdf

Crashworthy seat info here
http://www.martin-baker.co.uk/crashw_Intro.htm

Airbags and explosive bolts on rotor blades add cost, complication and weight to an aircraft or reduce strength.

THe real problem would be what is to trigger the airbags… nothing worse than flying Nap of earth at 200km/h and having your rotors blown off by your own system because you got to close to the ground… firing them on impact is too late…

The same can be said about ejection seats on military aircraft, but the added cost, complication and weight have saved thousands of lives.
I think helicopter crew deserve similar survival gear, don’t you?

As for triggering the system, I think the same sort of arrangement as a ejection seat would do fine in most cases.

The sad news about the RN Lynx crash reminded me of this thread, lets hope more can be done to improve survivability soon.
Have found this info on the Israeli system
http://www.rafael.co.il/web/rafnew/products/air-reaps.htm
Brochure
http://www.rafael.co.il/web/rafnew/products/brochures/REAPS.pdf