To: Vfrpilotpb
The problem with the use of explosive bolts to sever a rotorblade from the rotorhead is that the reliability of the explosive bolt would have to be 1. This would require multiple squibs, multiple firing paths and multiple explosive charges. Also required is the correct material in the bolt to make it 100% frangible 100% of the time. If there were a slight delay in the firing of the squibs in the bolts attaching one blade the ensuing vibration / out-of-balance would tear the helicopter apart.
Regarding ejection seats in helicopters the first Cheyenne flight vehicle had an ejection seat. It was downward firing and saw service in a Boeing B-47. On the one flight where it could have been used the helicopter was too close to the surface of the Pacific Ocean to be of any use. The helicopter suffered rotor incursion killing the pilot.
The Robinson does not need a system of explosive separation of the rotor system from the helicopter. If the helicopter is mishandled the separation will occur automatically.