What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The instructor and student had been in a hover approx. 20 minutes, two(2) feet off the ground, when a loud noise was heard in the transmission compartment behind them and a subsequent loss of main rotor drive. A routine "hovering autorotation" was performed by the instructor with very little consequence. No injuries to the occupants and no post-event fire. The helicopter's l/h skid was found to be slightly bent (repairable) at the aft, lwr attaching strut point. No other damage to the helicopter was found. The powerplant was operating normally.
As the FAA filed it
(-23) THE INSTRUCTOR AND STUDENT HAD BEEN IN A HOVER APPROX. 20 MINUTES, TWO(2) FEET OFF THE GROUND, WHEN A LOUD NOISE WAS HEARD IN THE TRANSMISSION COMPARTMENT BEHIND THEM AND A SUBSEQUENT LOSS OF MAIN ROTOR DRIVE. A ROUTINE "HOVERING AUTOROTATION" WAS PERFORMED BY THE INSTRUCTOR WITH VERY LITTLE CONSEQUENCE. NO INJURIES TO THE OCCUPANTS AND NO POST-EVENT FIRE. THE HELICOPTER'S L/H SKID WAS FOUND TO BE SLIGHTLY BENT (REPAIRABLE) AT THE AFT, LWR ATTACHING STRUT POINT. NO OTHER DAMAGE TO THE HELICOPTER WAS FOUND. THE POWERPLANT WAS OPERATING NORMALLY.