What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) The aircraft involved in this accident is operated by the Ohio State highway patrol, as a "public use" aircraft, maintained under title 14 CFR, part 91 rules. The following narrative was derived from pilot statements: during a training flight at the (osu) airport, and American Eurocopter instructor pilot and a Ohio State highway partrolman pilot receiving recurrent training were practicing autorotations. During the autorotation with a turn, the helicopter rotor RPM was high and the instructor pilot told the flying pilot to shallow out his deceleration to maintain the rotor RPM within limits. The touch down was cushioned, but due to the lack of time and high rotor RPM, there was not enough time to recover with power and the decision to touchdown was made. The touchdown was minimal impact, but slid for 40 ft on uneven terrain rocking side to side and fore and aft until the aircraft came to a stop. There was no indication of a problem and the training continued. Two more 180 degree autorotations were conducted before the training session was terminated. Neither pilot detected the post flight tailboom damage. The damaged tailboom was found on the next day preflight inspection.
As the FAA filed it
(-23) THE AIRCRAFT INVOLVED IN THIS ACCIDENT IS OPERATED BY THE OHIO STATE HIGHWAY PATROL, AS A "PUBLIC USE" AIRCRAFT, MAINTAINED UNDER TITLE 14 CFR, PART 91 RULES. THE FOLLOWING NARRATIVE WAS DERIVED FROM PILOT STATEMENTS: DURING A TRAINING FLIGHT AT THE (OSU) AIRPORT, AND AMERICAN EUROCOPTER INSTRUCTOR PILOT AND A OHIO STATE HIGHWAY PARTROLMAN PILOT RECEIVING RECURRENT TRAINING WERE PRACTICING AUTOROTATIONS. DURING THE AUTOROTATION WITH A TURN, THE HELICOPTER ROTOR RPM WAS HIGH AND THE INSTRUCTOR PILOT TOLD THE FLYING PILOT TO SHALLOW OUT HIS DECELERATION TO MAINTAIN THE ROTOR RPM WITHIN LIMITS. THE TOUCH DOWN WAS CUSHIONED, BUT DUE TO THE LACK OF TIME AND HIGH ROTOR RPM, THERE WAS NOT ENOUGH TIME TO RECOVER WITH POWER AND THE DECISION TO TOUCHDOWN WAS MADE. THE TOUCHDOWN WAS MINIMAL IMPACT, BUT SLID FOR 40 FT ON UNEVEN TERRAIN ROCKING SIDE TO SIDE AND FORE AND AFT UNTIL THE AIRCRAFT CAME TO A STOP. THERE WAS NO INDICATION OF A PROBLEM AND THE TRAINING CONTINUED. TWO MORE 180 DEGREE AUTOROTATIONS WERE CONDUCTED BEFORE THE TRAINING SESSION WAS TERMINATED. NEITHER PILOT DETECTED THE POST FLIGHT TAILBOOM DAMAGE. THE DAMAGED TAILBOOM WAS FOUND ON THE NEXT DAY PREFLIGHT INSPECTION.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.