Primary finding
Probable cause
The main rotor blade’s contact with the vertical stabilizer during the engine shutdown in strong, gusty wind conditions.
Investigator assessment
Analysis narrative
During an engine shutdown procedure following an emergency medical services flight, a main rotor blade sustained substantial damage when it contacted the left vertical stabilizer. The main rotor blade was broken near its root, and the tailboom and tail rotor driveshaft cover were dented. The local recorded wind was 25 knots gusting to 34 knots. The damage was consistent with the main rotor blade flapping with the gusty wind conditions and impacting the stabilizer. The operator reported that there were no preaccident mechanical malfunctions with the helicopter.
Source record
Factual narrative
During an engine shutdown procedure following an emergency medical services flight, a main rotor blade sustained substantial damage when it contacted the left vertical stabilizer. The main rotor blade broke near its root and the tailboom and tail rotor driveshaft cover were dented. The operator reported that there were no mechanical malfunctions with the helicopter. Local recorded winds were 190 degrees at 25 knots gusting to 34 knots.