Narrative:

Due to the fact that the tail boom structural damage was noticed pre-flight (by maintenance) on next day. I have not yet seen this damage; but was notified by my supervisor that it was found during maintenance pre-flight this morning. In his words; 'tailboom and drive shaft crumpled; noticeable'. My narrative is an assumption of what 'could have been the cause' as nothing out of the normal occurred during flight outside of what was noted below. No damage was noted during pre-flight by either pilot or myself. We did confirm that grease on tailboom was due to recent greasing by mechanics of the spider gear on tail rotor.normal pilot recurrent training; planned for [1 hour] of nvg/night training followed by check ride. All training maneuvers were conducted (in my estimation) within safe parameters with nothing significant to note; with one exception. Our initial hovering autorotation (pilot at controls) within 5-10 minutes after takeoff; had a more abrupt landing than any of the rest. I estimated that we initiated at approximately 4-5 feet; but initial pilot collective input took us to 6-7 feet. I placed my hands on collective to prevent further travel up until we were closer to the ground of which pilot used remaining collective to cushion landing. It was abrupt; but not enough to warrant me inspecting (or so I thought at the time) any of the structures. The rest of the flight concluded and the aircraft flew normally throughout the entire flight...no vibrations or anything out of the ordinary that I could detect. Post-flight; pilot performed walk around in the dark with flashlight vs. In the hangar while I opened the hangar door and secured the tractor for tow in. I visually looked at the aircraft from the front on both sides; checking for panels; etc. I then walked back to the tail rotor to inspect the grease thrown once in hangar. I have to admit that I don't remember looking specifically at the tailboom connection points during walk around and due to the damage noted; it is apparent that neither I nor the pilot in training looked at this aircraft structure point during walk around or during towing operations or during my drop off of maintenance logbook post-flight.

Related reports:

Google
 

Original NASA ASRS Text

Title: AS-350 check pilot reported the possibly cause of tailboom damage discovered by maintenance the morning after a training flight.

Narrative: Due to the fact that the tail boom structural damage was noticed pre-flight (by maintenance) on next day. I have not yet seen this damage; but was notified by my supervisor that it was found during maintenance pre-flight this morning. In his words; 'tailboom and drive shaft crumpled; noticeable'. My narrative is an assumption of what 'could have been the cause' as nothing out of the normal occurred during flight outside of what was noted below. No damage was noted during pre-flight by either pilot or myself. We did confirm that grease on tailboom was due to recent greasing by mechanics of the spider gear on tail rotor.Normal pilot recurrent training; planned for [1 hour] of NVG/night training followed by check ride. All training maneuvers were conducted (in my estimation) within safe parameters with nothing significant to note; with one exception. Our initial hovering autorotation (pilot at controls) within 5-10 minutes after takeoff; had a more abrupt landing than any of the rest. I estimated that we initiated at approximately 4-5 feet; but initial pilot collective input took us to 6-7 feet. I placed my hands on collective to prevent further travel up until we were closer to the ground of which pilot used remaining collective to cushion landing. It was abrupt; but not enough to warrant me inspecting (or so I thought at the time) any of the structures. The rest of the flight concluded and the aircraft flew normally throughout the entire flight...no vibrations or anything out of the ordinary that I could detect. Post-flight; pilot performed walk around in the dark with flashlight vs. in the hangar while I opened the hangar door and secured the tractor for tow in. I visually looked at the aircraft from the front on both sides; checking for panels; etc. I then walked back to the tail rotor to inspect the grease thrown once in hangar. I have to admit that I don't remember looking specifically at the tailboom connection points during walk around and due to the damage noted; it is apparent that neither I nor the pilot in training looked at this aircraft structure point during walk around or during towing operations or during my drop off of maintenance logbook post-flight.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.