Eurocopter AS 350 B2 N918EM accident near Kingfisher, Oklahoma

Probable cause

The pilot’s impaired judgment, due to medications, which led to an abrupt low-level maneuver and subsequent impact with trees and terrain.

NTSB analysis

The surviving paramedic reported that while en route to the destination hospital to pick up a patient, a conversation began about flying on a coyote hunt. The pilot abruptly began a low-level maneuver in an attempt to demonstrate a coyote hunt flight. As the pilot maneuvered at low level, the helicopter and main rotor blades impacted trees and then terrain. An examination of the airframe and engine did not reveal any preimpact malfunctions or failures that would have precluded normal operation. Toxicological testing performed on specimens from the pilot detected the presence of numerous medications, including hydrocodone (a prescription narcotic for pain treatment), diazempam (a prescription medication with sedative effects) and chlorpheniramine (an over-the-counter sedating antihistamine). It is likely that these medications would have impaired the pilot’s judgment and ability to maintain control of the helicopter. A review of the pilot’s medical history found medical treatment for several conditions that were not reported to the Federal Aviation Administration, the certificate holder, or the operator.

Text from the NTSB. Open the NTSB docket for CEN10FA424 for the full record.