Pilot Debrief

ROBINSON R44 near Colorado City, TX — 2020-12-10

Final reportCEN21LA084
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Date
2020-12-10
Location
Colorado City, TX, USA
Aircraft
ROBINSON R44
Registration
N7085Z
Category
Helicopter
Highest injury
Fatal
Fatalities
2

Probable cause

The pilot’s loss of control and exceedance of performance and/or structural limitations during low-altitude operations, which resulted in an inflight breakup.. Contributing to the accident was the pilot’s impairment from the effects of tetrahydrocannabinol.

Contributing factors

Contributing to the accident was the pilot’s impairment from the effects of tetrahydrocannabinol.

NTSB narrative

The pilot and passenger departed on a flight to herd cattle via helicopter. There were no witnesses to the accident. Examination of the wreckage and debris pattern was consistent with an inflight break-up at low altitude. Main rotor blade contact marks were found on the cabin section of the fuselage and likely occurred before ground impact. No preimpact anomalies were found with helicopter or engine. Toxicology of the pilot identified high levels of delta-9-tetrahydrocannabinol (THC, the active compound in cannabis), as well as its active and inactive metabolites. Even accounting for postmortem redistribution, the levels of THC detected indicated recent use of cannabis and a very high likelihood of impairment. Given that gastric and liver levels were very high while lung levels were much lower, it is likely that the pilot used an edible form of the drug. Based on the available information, it is likely that the pilot lost control and exceeded the performance and/or structural limitations of the helicopter while flying at low-level, resulting in an inflight breakup. It is likely that the pilot’s impairment from his recent use of cannabis contributed to the accident.

Analysis

Primary failure mode
Human factors
First missed decision gate
Pilot's decision to fly under the influence of THC could have been avoided.

NTSB coding

Evidence available

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

Docket documents9

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