Pilot Debrief

Hughes 369 near Riverside, CA — 2018-08-17

Final reportWPR18LA226
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Date
2018-08-17
Location
Riverside, CA, USA
Airport
RAL
Aircraft
Hughes 369
Registration
N105JL
Category
Helicopter
Highest injury
Serious
Fatalities
0
Phase of flight
Approach

Probable cause

The instructor’s delayed remedial action to an excessive descent rate during a simulated autorotation, which resulted in a hard landing.

NTSB narrative

The pilot receiving instruction was performing a full-touchdown, 180° autorotation when the instructor noted that the helicopter was going to be short of the intended landing zone and advanced the throttle to initiate a power recovery. The helicopter continued to descend and landed hard and rolled over, resulting in substantial damage. The instructor reported no mechanical malfunctions with the helicopter or engine that would have precluded normal operation. It is likely that the instructor’s delayed response to the helicopter’s excessive rate of descent resulted in the hard landing. After egressing the helicopter, the instructor noted that the pilot receiving instruction had been ejected from the helicopter during the accident sequence. Examination of the restraint systems revealed that the cotter pins for the hook-end fitting that attached to the airframe seat belt fittings had not been installed. The centrifugal force generated by the rotation of the helicopter during the accident sequence was likely sufficient for the hook-end fitting, void of the cotter pin, to separate from the seat belt fitting, which then resulted in the student being ejected from the helicopter. As a result of the accident, the manufacturer issued a mandatory service bulletin requiring the installation of cotter pins in the seat belt assemblies.

Analysis

Primary failure mode
Human factors
First missed decision gate
Instructor could have aborted the landing when realizing they were short of the landing zone.

NTSB coding

Evidence available

  • Photos
  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

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