Accident Summary
On July 24, 2010, at 1120 eastern daylight time, an experimental amateur-built Nadig Avid Aircraft Aerobatic, registration N579PN, impacted terrain shortly after takeoff from Venango Regional Airport (FKL) in Franklin, Pennsylvania. The pilot/owner and a pilot-rated passenger were killed, and the airplane sustained substantial damage. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was conducted under 14 CFR Part 91 as a personal flight.
Witness Observations
A witness reported observing the airplane perform three touch-and-go landings on runway 21 in a left traffic pattern before the accident. Another witness stated hearing the engine surging (revving up and down) followed by the sound of impact behind his home.
Pilot Information
The pilot/owner, seated in the left seat, held a private pilot certificate with an airplane single-engine land rating. His most recent third-class medical certificate was issued on October 27, 2008, with the limitation that he must wear corrective lenses for distant vision and possess glasses for near vision. He reported 936 total flight hours at the time of the medical examination.
The pilot-rated passenger, seated in the right seat, held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. His most recent third-class medical certificate was issued on April 4, 2007, with limitations requiring corrective lenses for near and distant vision and not valid for any class after those limitations. He reported 4,640 total flight hours.
Aircraft Information
The amateur-built airplane, serial number 579, received an experimental airworthiness certificate on October 25, 1990. It was powered by a Rotax 582 auto-fueled, liquid-cooled engine rated at 65 horsepower. The last inspection of the airframe and engine occurred on May 1, 2010, at which time the aircraft had accumulated 188 total hours. The pilot/owner purchased the airplane on May 7, 2010.
Meteorological Conditions
At 1115, the automated surface weather observation at Venango Regional Airport reported wind variable from 230 to 290 degrees at 7 knots, visibility 10 miles, broken clouds at 1,700 and 12,000 feet above ground level, temperature 27°C, dew point 23°C, and altimeter setting 30.04 inches of mercury.
Wreckage and Impact
The accident site was approximately three-quarters of a mile east of the departure end of the runway, in a wooded area behind a residence. The airplane struck trees while flying east before descending, impacting the ground and coming to rest flat. Flight control continuity was established, and all flight control surfaces were located on the airplane. The tail section came to rest under the right wing, while the cockpit area remained intact. One of the two propeller blades was bent aft. Engine control continuity was established. The engine rotated and thumb compression was achieved. Evidence of fuel was observed in the airplane's fuel system and at the accident site. The engine was retained for further examination.
Engine Examination
The engine was examined and run at the Rotax facility in Canada with oversight from the Transportation Safety Board of Canada. External examination revealed that the intake manifolds had been modified with non-standard materials, secured by adhesive tape. The spark plugs and ignition wires were also non-standard components. Inspection of the carburetors revealed deposits of an unknown substance on the floats and at the bottom of the carburetor bowl. During the engine test run, a blocked idle jet in one of the two carburetors was found, preventing normal operation. The engine would run only momentarily when raw fuel was sprayed directly into the carburetors. After the blockage was removed, the engine started and ran to normal limits with no further anomalies.
Medical Information
A postmortem examination of the pilot conducted by the forensic pathologist in Erie, Pennsylvania, determined the cause of death as blunt force trauma. Toxicology testing performed by the FAA Civil Aeromedical Institute (CAMI) on specimens from the pilot and passenger detected no carbon monoxide, cyanide, or ethanol. Ranitidine was detected in the passenger.