CEN13FA241

Two witnesses reported seeing an airplane matching the description of the accident airplane flying in the area of the departure airport at very low altitudes about 90 minutes before the accident flight. One witness described the flight profile as similar to "crop-duster type operations, with multiple low-altitude passes." Another witness reported that the airplane departed the airport and climbed to about 1,000 feet and then made a gradual eastbound descent to a low altitude and out of sight. He reported that the airplane reappeared in a very steep left bank and then descended out of sight again. About 3 miles east of the airport, the airplane impacted a 20-foot-high power line, which resulted in the vertical stabilizer separating from the top of the fuselage and the airplane becoming uncontrollable until it impacted terrain. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A parallel set of high-tension power lines with large support poles was located about 1/2 mile east of the impacted power line. As the pilot flew the airplane at a low altitude eastbound, the high-tension power lines likely visually aligned (that is, came within the same line of sight) with the impacted power line. Therefore, it is likely that the pilot was focused on the more prominent high-tension power lines and did not observe the impacted power line.

The accident airplane, a Piper PA28R-180 (serial number 28R-30317) was manufactured in 1977. It was registered with the Federal Aviation Administration (FAA) on a standard airworthiness certificate for normal operations. The airplane showed a total time of 9,937 hours as of the last annual inspection, which was completed on January 17, 2013. The airplane was equipped with a Lycoming IO-360-B1E engine (serial number L29830-51E). As of the last annual inspection, the engine had accumulated a total of 5,629 hours, with 1,449 hours since last major overhaul. On April 27, 2013, at 1959 central daylight time, a Piper PA-28R-180 airplane, N3970T, was substantially damaged during a wire strike and subsequent ground impact near Norfolk, Nebraska. Both occupants, the private pilot and passenger, were fatally injured. The airplane was registered to Pro-Flite Incorporated and was operating under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and a flight plan was not filed. The flight departed from Norfolk Regional Airport (OFK), Norfolk, Nebraska at 1957. Multiple witnesses who were piloting radio controlled airplanes on the south end of the airport saw the accident airplane takeoff from Runway 14 at OFK. After climbing to about 1,000 feet above ground level (AGL), the airplane began a steady descent eastbound to a low altitude and out of sight. Seconds later, the airplane reappeared in a steep left bank and then descended out of sight again. Previous to the accident flight, the pilot and passenger departed Millard Airport (MLE), Omaha, Nebraska, at 1801 for their flight into OFK. About 1830, two witnesses noticed an airplane similar in type, color, and design to the accident plane flying at low altitude about 6 miles southeast of OFK. The first witness noticed this airplane flying about 100 feet AGL, banking left and right to follow a river basin. From a different location, the second witness characterized the airplane's maneuvers as similar to crop duster operations, with multiple low altitude passes about 15 to 20 feet AGL. On April 29, 2013, an autopsy was performed on the pilot by a forensics pathologist at the Douglas County Morgue, as authorized by the Madison County Attorney. The cause of death was attributed to blunt force injuries. The FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. No carbon monoxide, ethanol, or drugs were detected in the blood. The weather observing station at OFK reported the following conditions at 1956: wind 170 degrees at 9 knots, visibility 10 miles, clear skies, temperature 21 degrees Celsius, dew point 3 degrees Celsius, altimeter setting 29.89. The pilot, age 26, held a private pilot certificate with an airplane single-engine land and instrument ratings. On March 25, 2010, the pilot was issued a Class 1 limited medical certificate, which required corrective lenses be worn. A review of thepilot's flight logbook indicated that he had logged 212 hours total time, with 40 hours in the make and model of the accident airplane. He had successfully completed the requirements of a flight review on September 25, 2012. About 1/2 mile east of the impacted power line/wire was a set of high tension power lines, also oriented in a north-south direction. From a position west of the impacted power line, the high tension power lines visually align (same line of sight) with the impacted power line. Additionally, the much larger support poles and lines of the high tension power lines were more visually prominent than the impacted power line. The wreckage came to rest upright against a line of trees bordering a farm field. The fuselage with the right wing attached was found lying against trees. The left wing remained partially attached by control cables. The engine and its mount were attached to the firewall. The propeller and spinner were separated and laying approximately 8 feet in front of the nose of the airplane. A severed, 20-foot high power line/wire was located about 1,418 feet from the impact site. The power line ran parallel to a north-south gravel road. A debris path, which included the rotating beacon lens from the top of the vertical stabilizer, was on a heading of 093 degrees from the wire strike. The heading from the wire strike to the wreckage site was 060 degrees, with a line of trees about 50 feet high separating the wire strike and the wreckage site. The airplane's windshield, top of the fuselage, and leading edge of the vertical stabilizer indicated damage consistent with a wire strike. The vertical stabilizer was found separated from the top of the fuselage. Both the forward and aft fin to fuselage attach bracket rivets were sheared. The engine power levers (throttle, prop, mixture), were in the mid-travel positions. The horizontal stabilizer trim indicator was in the full nose down position. Flight control continuity was confirmed to all flight control surfaces. Fuel was observed at all fuel system components and fuel carrying lines were intact with no leaks. All fuel system components were secure on their mounts. During disassembly, no defects or contaminants were observed. The fuel injector nozzles were removed and examined, with no obstructions observed. The engine driven diaphragm fuel pump was removed from its respective mount and discharged fuel when actuated by hand. Spark plugs were observed to have a color consistent with normal combustion, when compared to the Champion Spark Plug Wear Guide. Both magnetos were secure on their respective mounts. The left magneto was impulsed and furnished spark at all outlet points. The right magneto was rotated by hand and no spark was furnished. During follow on testing, the right magneto was spun using a socket and a spark was observed at all outlet points. All engine cylinders were visually inspected using a lighted bore scope, with no anomalies noted. The engine pistons displayeda normal carbon deposit on their tops, and the intake and exhaust valves were unremarkable. A turning tool was inserted into the vacuum pump drive pad and the engine was rotated by hand. Thumb suction and compression was obtained at all cylinders and valve train and crankshaft continuity was observed. All accessory gears were observed rotating. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.