Jul 6, 2017
Accident
Substantial Big Lake, MN
InjuriesNone
Phase of Flight-
ConditionsVMC
OperationFAR 137
Probable Cause
The failure of the metal core assembly within a wooden main rotor blade due to undetected corrosion and fatigue, which caused the wooden blade to separate from the rotor mast.
NTSB CEN17LA264