History of Flight
On September 15, 2012, at approximately 0950 central daylight time, a Republic RC-3 amphibious airplane, registration N6072K, struck electrical transmission lines while approaching Weiss Lake near Cedar Bluff, Alabama. The certificated private pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. The flight had departed from Guntersville Municipal Airport (8A1), Guntersville, Alabama.
According to a friend of the pilot who lived on Weiss Lake and owned the same model of airplane, the purpose of the flight was to visit him. The pilot was familiar with the lake and the transmission lines crossing it. The friend noted the pilot usually landed in the opposite direction from that used on the day of the accident to allow for any "overrun" after landing; he could not explain why the pilot landed in the direction he did.
The friend observed the airplane turn east and pass over his house at about 400 feet above ground level. The airplane then turned left to reverse direction and began descending. Moments later, it struck a set of unmarked electrical transmission lines near the eastern edge of the lake. The airplane pitched nose up, its forward motion appeared to stop, then it rolled to the right until inverted, fell onto the lake surface, and sank.
A witness fishing on the lake saw the airplane flying along the north side just above tree top height when it hit the power line. The airplane pitched up, the right wing dropped, and it struck the water inverted. The engine was running and its sound did not change until impact.
Personnel Information
FAA records showed the pilot held a private pilot certificate with ratings for airplane single-engine land and single-engine sea. His most recent third-class medical certificate was issued on April 19, 2010, at which time he reported 400 total hours of flight experience.
Aircraft Information
The accident aircraft was a pusher-configured, high-wing, tail-wheel-equipped amphibious airplane of conventional metal construction. It was powered by a 215-horsepower, air-cooled, six-cylinder engine driving a three-bladed constant-speed variable-pitch propeller. The airplane was manufactured in 1947. Its most recent annual inspection was completed on November 1, 2011, at which time it had accrued 1,027.2 total hours of operation.
Meteorological Information
The recorded weather at Isbell Field Airport (4A9), Fort Payne, Alabama, about 19 nautical miles northwest of the accident site at 0955, included calm winds, visibility 10 miles, sky clear, temperature 23°C, dew point 15°C, and an altimeter setting of 30.21 inches of mercury.
Wreckage and Impact Information
Examination of the accident site revealed the airplane came to rest inverted in Weiss Lake about 200 yards from the shoreline. Only the nose (bow) and left pontoon were visible above water. Comparison of wreckage location to the transmission right-of-way indicated the airplane was traveling on a heading of 220 degrees before contacting one of the lines.
Post-recovery examination revealed no evidence of preimpact failure or malfunction of the airplane or engine that would have precluded normal operation. The cable initially contacted the airplane just below the windshield; the nose was crushed back into the cabin area. Impact damage on the upper leading edges of both wings indicated the airplane was inverted with forward motion when it hit the water. The engine cowling was crushed, but the pusher propeller was intact and the engine undamaged. Flight control continuity was confirmed from cockpit controls to surfaces. The throttle, mixture, and propeller controls were found in the full forward position.
Medical and Pathological Information
An autopsy by the Alabama Department of Forensic Sciences listed cause of death as blunt force injuries. Toxicological testing at the FAA Bioaeronautical Sciences Research Laboratory was negative for carbon monoxide, cyanide, and basic, acidic, and neutral drugs, except for Naproxen (a nonsteroidal anti-inflammatory drug), Ranitidine (an antihistamine for gastric acid secretion), and Valsartan (an angiotensin receptor blocker for high blood pressure).
Tests and Research
Observation of the transmission lines from the shore revealed they were hard to see and did not contrast well with the surrounding terrain given the color of the sky, water, and cloud cover. The lines were unmarked and strung between 158-foot-tall electrical transmission towers within a corridor crossing the lake from north to south. The airplane struck a static line normally above the conductors; during impact, the static line separated from the northern tower and dangled into the lake. The "Goat Head" (arm) of the lattice-type tower was bent downward 45 degrees. Aeronautical charting information showed the lines were depicted on the Atlanta Sectional Chart.
Additional Information
To improve safety, the Tennessee Valley Authority installed spherical high-visibility wire markers on the electrical transmission lines crossing Weiss Lake.