20240713009629A

The second air tour of the day started at 10:15AM. As the pilot approached viewing site he began a slow gradual deceleration and aimed to position the archaeological ruins out the left door so the passenger on the left rear side could take photos. As the pilot started a gradual descent he prepared to fly away from the site and at this point the aircraft experienced a sudden and un-commanded right yaw. The pilot immediately applied left pedal to arrest the yaw rate and lowered the nose to fly out of it. The aircraft continued to spin to the right. The pilot realized that the left pedal was fully extended and the rotor speed was low. All other instrumentation was normal. When the low rotor speed alert sounded the pilot immediately increased collective to stabilize the rotor speed. The pilot then noticed an increase in the flashing digits on the tot, indicating that the turbine temperature was going high. The spin to the right continued to be uncontrollable. The pilot decided to lower the collective and force the nose over and conduct a low-level auto rotation onto the hard surface below. The aircraft entered a state of autorotation. The airspeed began to increase, and the yaw ceased, and the left side landing gear struck the surface first and broke off. The aircraft bounced a few times and continued to skid forward without coming to a rest, the aircraft then began to climb back into the air. At this point the pilot decided to fly the aircraft back to P52. Once at the Cottonwood Airport the pilot put the aircraft into a low hover, and with the assistance of another pilot, they evacuated the three passengers off the aircraft and escorted them inside the terminal. The pilot repositioned the aircraft over a grassy area off the runway and shut off the fuel. When the engine began to spool down the pilot lowered the collective and the aircraft settled onto its left side.