Helicopteres Guimbal CABRI G2 N372PA accident near Cahokia, Illinois

Probable cause

The lack of proper attachment of the cyclic control that resulted in a loss of control during a landing approach and impact with terrain. Contributing to the accident was the improper maintenance performed.

NTSB analysis

The flight instructor stated that during an instructional flight he lost left cyclic control during an approach for landing. The student pilot’s right cyclic controls continued to function, and the flight instructor coached him on cyclic control inputs to maintain control of the helicopter. The student’s cyclic control became unresponsive to control inputs during the attempted landing and the helicopter impacted the ground resulting in substantial damage to the main rotor blades. Postaccident examination of the flight control system revealed that retaining hardware for the pins used to attach the left cyclic control were not installed. Maintenance personnel were unable to provided information regarding previous maintenance performed on the cyclic controls. The left cyclic control did not have any deformation/damage.

Text from the NTSB. Open the NTSB docket for CEN23LA150 for the full record.