CEN14FA224

The pilot's decision to continue the flight into known deteriorating weather conditions at a low altitude and his subsequent failure to remain clear of an unlit wind turbine. Contributing to the accident was the inoperative obstruction light on the wind turbine, which prevented the pilot from visually identifying the wind turbine.

During a dark night cross-country flight, the instrument-rated pilot was approaching the intended airport for landing when the airplane collided with the blades of a wind turbine tower. The weather had started to deteriorate and precipitation echoes were observed on radar. Witnesses in the area described low clouds, windy conditions, and precipitation. In addition, weather briefing records and statements made to a witness indicate that the pilot was aware of the current and forecast weather conditions for the route of flight. Investigators were unable to determine why the airplane was operating at a low altitude; however, the pilot was likely attempting to remain clear of the clouds even though both the pilot and the airplane were capable of flying in instrument meteorological conditions. An examination of the airplane, systems, and engine revealed no anomalies that would have precluded normal operation. Toxicology findings revealed a small amount of ethanol in the pilot's blood, which was unlikely due to ingestion since no ethanol was found in liver or muscle tissue. The investigation revealed that the wind turbine farm was not marked on either sectional chart covering the accident location; however, the pilot was familiar with the area and with the wind turbine farm. Investigators were not able to determine what the pilot was using for navigation just before the accident. The light on the wind turbine tower that was struck was not operational at the time of the accident, and the outage was not documented in a notice to airmen. The wind turbine that was struck was the 5th tower in a string of towers oriented east to west, then the string continued south and southwest with an additional 13 towers. If the pilot observed the lights from the surrounding wind turbines, it is possible that he perceived a break in the light string between the wind turbines as an obstacle-free zone.

HISTORY OF FLIGHT On April 27, 2014, about 2116 central daylight time (CDT), a Piper PA-32R-300 airplane, N8700E, was destroyed during an impact with the blades of a wind turbine tower 10 miles south of Highmore, South Dakota. The commercial pilot and three passengers were fatally injured. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Dark night instrument meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from Hereford Municipal Airport (KHRX), Hereford, Texas, approximately 1700, and was en route to Highmore Municipal Airport (9D0), Highmore, South Dakota. According to family members, the pilot and three passengers had been in Texas for business. The pilot's family reported that they had intended to leave earlier in the day, on the day of the accident, but elected to delay, and subsequently left later than they had planned. The family stated that most likely, the flight was going to stop at 9D0 to drop off one passenger before continuing to Gettysburg Municipal Airport (0D8), Gettysburg, South Dakota. A fixed base operator employee at KHRX witnessed the pilot fuel the accident airplane at the self-serve fuel pump just prior to the accident flight. He reported that the fuel batch report showed 82.59 gallons of fuel had been dispensed. The pilot commented to the employee that he was going to "top it off" as he had "pushed his luck on the trip down." The pilot also discussed the weather conditions in South Dakota, noting that it was raining there. The pilot also added that the only reason they were leaving was because one of the passengers was anxious to get home. The pilot contacted the Fort Worth Lockheed Martin Contract Flight Service Station at 1711 when the airplane was 38 miles west of Borger, Texas, on a direct flight to North Platte, Nebraska. The pilot requested and obtained an abbreviated weather briefing. During this briefing, winds aloft and weather advisories for the reported route of flight were provided. The pilot also provided a pilot report for his position. At 1812 the pilot sent a text stating that they were "Into KS aways" (sic). At 1923 he sent a text stating that they were "into NE". At 2054 he stated that they were flying by Chamberlain, South Dakota. Several witnesses in the area reported seeing an airplane fly over their homes the evening of the accident. The first witness, located near the shore of the Missouri River, near Fort Thompson, South Dakota, reported seeing an airplane about 200 feet above the ground, flying to the northeast, about 2045. He stated that the airplane was low and was moving quickly. The second witness, located a few miles southwest of the accident site, reported seeing an airplane flying at a very low altitude, headed north, about 2115. Neither witness reported hearing problems with the engine. According to the Federal Aviation Administration (FAA), the airplane was reported missing by a concerned family member when the airplane did not arrive in Gettysburg, South Dakota, on the evening of April 27, 2014. The wreckage of the airplane was located by members of the Hyde County Fire Department and the Hyde County Sheriff's department around 0330 on the morning of April 28, 2014. The pilot was not communicating with air traffic control at the time of the accident and radar data for the accident flight was not available. OTHER DAMAGE Wind turbine tower #14, part of the South Dakota Wind Energy Center owned by NextEra Energy Resources, was damaged during the accident sequence. One of the three blades was fragmented into several large pieces. One large piece remained partially attached to a more inboard section of the turbine blade. The inboard piece of this same turbine blade remained attached at the hub to the nacelle. The outboard fragmented pieces of the wind turbine blade were located in a radius surrounding the base of the wind turbine tower. The other two wind turbine blades exhibited impact damage along the leading edges and faces of the blades. PERSONNEL INFORMATION The pilot, age 30, held a commercial pilot certificate with airplane single engine land, multiengine land, and instrument ratings. He was issued a second class airman medical certificate without limitations on January 19, 2014. The pilot was a professional agricultural pilot and had flown agricultural airplanes in the area for several seasons. The family provided investigators the pilot's flight logbook. The logbook covered a period between April 22, 2010, and April 20, 2014. He had logged no less than 3,895.8 hours total time; 100.7 hours of which were in the make and model of the accident airplane and 95.1 hours of which were in the accident airplane. This time included 76.2 hours at night, 1.1 hours of which had been recorded within the previous 90 days. The pilot was current for flight with passengers at night. He successfully completed the requirements of a flight review on January 18, 2013. He successfully completed an instrument proficiency check in a PA-32R on February 7, 2014. According to the FAA, the pilot was familiar with the accident area. Specifically, the pilot was familiar with the wind turbine farm and had expressed his concern about the wind turbine farm to the FAA Flight Standards District Office in Rapid City, South Dakota. The details of his concerns were not available. AIRCRAFT INFORMATION The accident airplane, a Piper PA-32R-300 (serial number 32R-7680159), was manufactured in 1976. It was registered with the FAA on a standard airworthiness certificate for normal operations. A Lycoming IO-540-K1G5D engine rated at 300 horsepower at 2,700 rpm powered the airplane. The engine was equipped with a 2-blade Hartzell propeller. The airplane was equipped and certified for flight in instrument meteorological conditions. The airplane was maintained under an annual inspection program. A review of the maintenance records indicated that an annual inspection had been completed on April 17, 2013, at an airframe total time of 4,766 hours. METEOROLOGICAL INFORMATION The closest official weather observation station was Pierre Regional Airport (KPIR), Pierre, South Dakota, located 35 miles west of the accident location. The elevation of the weather observation station was 1,744 feet mean sea level (msl). The routine aviation weather report (METAR) for KPIR, issued at 2124, reported wind from 010 degrees at 19 knots, visibility 10 miles, light rain, sky condition broken clouds at 1,000 feet, overcast at 1,600 feet, temperature 6 degrees Celsius (C), dew point temperature 5 degrees C, altimeter 29.37 inches, remarks ceiling variable between 800 and 1,200 feet. The METAR issued at 2139 for KPIR reported wind from 070 degrees at 19 knots, visibility 4 miles, rain, mist, sky condition ceiling overcast clouds at 800 feet, temperature 6 degrees C, dew point temperature 5 degrees C, altimeter 29.37 inches, remarks ceiling variable between 600 and 1,300 feet. Huron Regional Airport (KHON) in Huron, South Dakota, was located 53 miles to the east of the accident site at an elevation of 1,289 feet. The METAR issued at 2055 for KHON reported wind from 100 degrees at 20 knots, gusting to 27 knots, visibility 10 miles, sky condition ceiling overcast at 1,000 feet, temperature 9 degrees C, dew point temperature 7 degrees C, altimeter 29.36 inches, remarks peak wind of 29 knots from 090 degrees at 2015, rain began at 1956 and ended at 2006. The National Weather Service (NWS) Surface Analysis Chart for 2200 CDT depicted a low-pressure center in southern Nebraska, with an occluded front extending into northeastern Kansas. A stationary front extended from northeastern Nebraska southeast through southern Iowa. Surface wind east of the accident location was generally easterly, with surface wind to the west of the accident loc