— TAHLEQUAH — The National Transportation Safety Board on Thursday released its probable causes report on a helicopter crash that killed two people in October 2009.

NTSB officials determined the pilot, 26-year-old Mark James Mahaney, was impaired “due to recent heavy use of methamphetamine, recent use of a narcotic pain reliever, and fatigue.”

Records indicated Mahaney had been prescribed a combination of propoxyphene and acetaminophen for pain following a tooth extraction and repair performed a day before the crash.

Darci Lynn Scraper, 20, was also killed in the crash, which occurred shortly after the 2007 Robinson R22 helicopter left Mahaney’s home en route to the Tahlequah airport, according to a factual report issued by the NTSB last April.

The NTSB also said Mahaney’s lack of instrument experience and training contributed to the crash. An exam of the aircraft and its systems revealed no anomalies, and Mahaney was not certified for instrument flight. There was also no evidence he had received any instrument training, or that he was certified for night flight.

Friends and family members of Mahaney said he’d been up all night watching movies, and intended to fly to Tahlequah Municipal Airport to meet a friend, hanger his helicopter, and go hunting. The helicopter never arrived, and the friend left the airport without reporting the overdue aircraft.

Scraper’s family filed a missing persons report Oct. 15, 2009, and the wreckage was found near Mud Valley Road after being spotted from the air by a pilot with the Oklahoma Highway Patrol.

Mahaney held a private pilot certificate with a rotorcraft helicopter rating that was issued July 31, 2009. He’d reported a total flight time of 85 hours when he applied for that certificate.

NTSB investigators said a review of Federal Aviation Administration records revealed Mahaney was sent a letter of investigation Sept. 2, 2009, which alleged he provided “false or fraudulent information” on his medical certificate application dated April 28, 2008, and had failed to report a motor vehicle action within 60 days, as required by FAA regulations.

The FAA said Mahaney didn’t respond to the letter or provide any evidence or a statement regarding its receipt. The FAA was initiating enforcement action against Mahaney when the crash occurred.