Mark,
that pic you posted is in this book, the chopper was anchored to the floor of wind tunnel (against Lockheeds' advice) for testing, blade flapping was encountered which sliced through the tail boom and the remains of fus broke away from the mounts and disappeared down the wind tunnel!
Fortunately there was no-one in cockpit at the time, heli was controlled remotely, though a 20lb rotor tip weight did crash through control room, but no-one was injured....
