Pilot Debrief

ROBINSON HELICOPTER R44 near Henderson, TX — 2022-06-06

Final reportCEN22LA234
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Date
2022-06-06
Location
Henderson, TX, USA
Airport
RFI
Aircraft
ROBINSON HELICOPTER R44
Registration
N94WC
Category
Helicopter
Highest injury
Serious
Fatalities
0
Phase of flight
Hover

Probable cause

The partial loss of engine power in a hover due to a stuck exhaust valve.

NTSB narrative

The helicopter pilot was practicing hover takeoffs and landings in a crosswind. The passenger reported that, while hovering before a landing, the helicopter shuddered, and the left skid contacted the ground. The helicopter rolled onto its left side. The helicopter sustained substantial damage to the main rotor blades, fuselage, and tail boom. Examination of the helicopter’s flight control systems and main and tail rotor drive systems did not show any preimpact anomalies that would have precluded normal operation. Examination of the No. 2 cylinder revealed that the exhaust push rod was bent and the exhaust valve was stuck. Borescope inspection of the No. 2 cylinder showed that the exhaust valve had contacted the piston and the intake valve appeared to be recessed in the No. 2 valve seat. The loss of engine power was most likely due to the stuck exhaust valve on the No. 2 cylinder.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the maneuver upon feeling vibrations during hover.

NTSB coding

Evidence available

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

Docket documents7

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