Primary finding
Probable cause
The flight instructor's delayed remedial action to maintain helicopter altitude during hover flight instruction, which resulted in the helicopter skid contacting a crack in the runway and a dynamic rollover.
Investigator assessment
Analysis narrative
**This report was modified on July 17, 2020. Please see the docket for this accident to view the original report.** The flight instructor reported that he was teaching his student to hover in the helicopter. The helicopter was in a 2-ft hover and began drifting to the left. The left rear skid got caught in a crack in the runway, and the helicopter rolled left. According to the flight instructor, the student pilot pulled up on the collective, and the instructor attempted to push the collective down; however, the student pilot reported that he was not aware the flight instructor had transferred control of the helicopter to him and was "tracking the progress of the flight instructor." A dynamic rollover occurred, and the helicopter rolled onto its left side. The flight instructor reported that wind gusts may have been a factor in the accident. According to the METAR that the flight instructor was monitoring about the time of the accident, the wind was from 210° at 8 knots. The METAR reported no wind gusts and no convective activity that day. The helicopter sustained substantial damage to the tailboom and the main rotor system. The pilots reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.
Source record
Factual narrative
The helicopter flight instructor reported that he was teaching his student to hover. The helicopter was at a 2-foot hover and began drifting to the left. The left rear skid contacted the ground and a left roll ensued. The student pilot pulled up on the collective, and the instructor attempted to push the collective down. A dynamic rollover occurred, and the helicopter rolled onto its left side. The flight instructor reported that wind gusts may have been a factor in the accident. According to the METAR that was being monitored by the flight instructor about the time of the accident, the wind was from 210° at 8 knots. No wind gusts and no convective activity was reported via METAR that day. The helicopter sustained substantial damage to the tailboom and the main rotor system. The pilots reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.