Incident Overview
A flight instructor conducted a training session involving a simulated engine failure after takeoff. When the helicopter reached approximately 50 knots, the pilot under instruction (PUI) pulled the cyclic aft and increased collective. The instructor joined the controls to prevent excessive collective input and to lower the helicopter's nose to a level attitude. Both pilots were on the controls as collective was increased to cushion the landing.
Landing and Subsequent Slide
The helicopter touched down on the paved runway's centerline. As it slid across what the pilots described as an uneven surface, the helicopter began to porpoise. The instructor lowered the collective to slow the slide. He then heard a noise, and the helicopter began to vibrate. It subsequently turned 220 degrees to the right before coming to a stop.
Aftermath
During the slide, a main rotor blade cut off the tail boom. Neither pilot reported any preexisting mechanical anomalies that would have precluded normal operation.