Accident Summary
On August 9, 2015, about 1855 central daylight time, an amateur-built RAF 2000 GT gyroplane, registration N315LK, was substantially damaged when it struck a pine tree near Humboldt, Iowa. The pilot sustained fatal injuries, and the passenger received serious injuries. The gyroplane was operated by a private individual under 14 Code of Federal Regulations Part 91 as a personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The flight departed from Humboldt Municipal Airport (0K7) at about 1825.
The passenger, who had flown with the pilot previously, stated the purpose was to take pictures of his house and fly around. After about 30 minutes, the pilot made a low pass over the passenger's house on a southwesterly heading. The passenger heard the pilot exclaim, followed by a descent. The pilot struggled with the controls as the gyroplane descended below tall trees. As the ground approached, engine power increased. The gyroplane turned right and hit a lone pine tree they had just passed. A neighbor observed the approach, heard a reduction in engine noise, then descent, followed by a rapid increase in engine noise and an impact sound.
Personnel Information
The 58-year-old pilot held a sport pilot certificate with a rotorcraft gyroplane rating and a repairman experimental aircraft builder certificate. His logbook showed 150.5 hours of gyroplane flight time, with over 14 hours in the accident gyroplane in the previous 90 days. He had never undergone an FAA medical certification examination.
Aircraft Information
The 2012 amateur-built RAF 2000 GT gyroplane had a single pusher engine, teetering blade rotor system, and two seats. It was powered by a four-cylinder Subaru EJ 2.2 engine driving a three-bladed Warpdrive composite propeller. The last inspection was a 25-hour inspection conducted by the pilot on July 9, 2015.
Meteorological Information
At 1915, the weather station at Fort Dodge Regional Airport (FOD), about 12 miles south, reported wind from 120 degrees at 3 knots, 10 miles visibility, clear skies, temperature 25°C, dew point 20°C, and altimeter 29.92 inches of mercury.
Wreckage and Impact Information
FAA personnel found the wreckage next to a lone pine tree in the passenger's front yard, elevation 1,134 feet msl. The gyroplane was on its side, nose northeast. Fuel leaked from several locations; no postcrash fire occurred. The rotor blade leading edge had no noticeable impact marks. The propeller blades were broken off at the root, with segments up to 200 feet away. Examination at the recovery location established flight control continuity except for two cyclic components fractured from impact. Engine crankshaft continuity was confirmed. No mechanical malfunctions or failures precluding normal operation were found.
Tests and Research
Fragments of the three composite propeller blades were examined at the NTSB Materials Laboratory. Each blade had fractured fragments near the root and long spanwise pieces with leading-edge impact damage. All blade tips were identified. No apparent anomalies or deficiencies in the composite structure were noted. A video recorder recovered from the site was evaluated by the NTSB Recorder Laboratory but contained no relevant information.
Medical and Pathological Information
An autopsy on August 11, 2015, by the Iowa Department of Public Health Examiner determined the cause of death as blunt force injuries. Toxicology tests by the FAA's Civil Aeromedical Institute identified atenolol, yohimbine, and etomidate in the pilot's blood. Atenolol is used for high blood pressure, yohimbine for male sexual dysfunction, and etomidate is an anesthesia induction agent. Hospital records indicated etomidate was used during lifesaving efforts.