Robinson Helicopter Company R44 II N442JE accident near Waterloo, Illinois

Probable cause

The malfunction of the flight controls for undetermined reasons.

NTSB analysis

The pilot reported that he was maneuvering at low altitude to apply fungicide to a corn field. The collective flight control stiffened to a point that the pilot was unable to arrest the helicopter’s descent rate. The pilot attempted to use cyclic control to flare the helicopter and arrest the descent; however, the cyclic control was not responsive, and the helicopter impacted the ground. The helicopter sustained substantial damage to the tail boom, fuselage, and main rotor system. The pilot stated that he suspected that the flight controls’ hydraulic assist system malfunctioned.

During the on-site inspection, no obvious anomalies were found with the flight control system. Flight control continuity was confirmed on site. All 3 servos (2 forward and 1 aft) passed bench functionality tests and the hydraulic pump, reservoir, and fluids were normal. The right forward servo had a slightly bent piston shaft, but still was fully functional. The bent shaft was consistent with impact damage. The spool drives of each servo were examined and exhibited signatures consistent with normal operation. An examination of the hydraulic system components revealed no anomalies that would have precluded normal operations. The reason for the reported flight control malfunction could not be determined.

Text from the NTSB. Open the NTSB docket for CEN22LA333 for the full record.