Pilot Debrief

ROBINSON HELICOPTER COMPANY R44 II near Wheeling, IL — 2021-08-11

Final reportCEN21LA369
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Date
2021-08-11
Location
Wheeling, IL, USA
Airport
PWK
Aircraft
ROBINSON HELICOPTER COMPANY R44 II
Registration
N4043B
Category
Helicopter
Highest injury
Minor
Fatalities
0
Phase of flight
Initial climb

Probable cause

A partial loss of engine power for reasons that could not be determined based on available information.

NTSB narrative

The pilot reported a decrease in engine and rotor rpm during cruise flight. The pilot reported that he heard sounds from the engine “like detonations,” and he placed the helicopter into autorotation and landed on a road. The helicopter rotor blades struck a pole and the helicopter rolled onto its right side. Downloaded data from the engine monitoring unit confirmed the decrease in engine and rotor rpm. Functional testing of the engine and electronic governor control revealed no anomalies. Bench testing of the engine rpm sensor and the electronic governor control unit also revealed no anomalies. During functional testing, it was confirmed that the manual throttle control could be used to override the governor control. Based on the available information, the reason for the decrease in engine rpm reported by the pilot could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have chosen to delay takeoff until engine issues were resolved.

NTSB coding

Evidence available

  • FDR / data
  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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