Robinson R44 N7085Z accident near Colorado City, Texas

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.

NTSB analysis

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.

Text from the NTSB. Open the NTSB docket for CEN21LA084 for the full record.