Many years ago (mid to late 1950s) an USCG Aviator flying a Bell HTL-1 (early model 47) suffered a heart attack. He slumped over the cyclic and immobilized the collective forcing it down slightly. The co-pilot was a senior mechanic with a lot of stick time and was capable of flying the helicopter. He found it extremely difficult to move the pilot back and to lock him in his harness.
The helicopter which was mounted on floats landed flat on the ground and bounced up and in the process of moving upward it turned over and landed on the mast severing the blades and in the process killing the mechanic.