A for what it is worth.....in this video....a Sikorsky S-58T lifting an AirCon from a RoofTop suffers a Tail Rotor Drive failure.....memory serves me the drive shaft couplings stripped causing the loss of drive with no components departing the aircraft.
I talked with the Pilot shortly after the event and he said he jettisoned the load and began to maneuver the aircraft towards a safe landing area and upon getting to a point he thought he could make an autorotation....he cut the engines.
When he lowered the nose to gain some airspeed to be able to flare.....is when it went all wrong.
He was genuinely remorseful when he said he regretted not being able to save the aircraft.