Highmore, SD, USA
N8700E
PIPER PA 32R-300
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 location generally northerly. Station models across the state of South Dakota depicted overcast skies, with temperatures ranging from the high 30's Fahrenheit (F) to the mid-50's F. Rain and haze were depicted across the state. A regional Next-Generation Radar (NEXRAD) mosaic obtained from the National Climatic Data Center (NCDC) for 2115 identified a large portion of South Dakota under light to moderate values of reflectivity, including the region surrounding the accident site. WSR-88D Level II radar data obtained at 2114 from Aberdeen, South Dakota, (KABR), depicted altitudes between 5,460 and 13,200 feet at the accident site. The KABR data identified an area of light reflectivity coincident with the accident location approximately two minutes prior to the accident time. Advanced Very High Resolution Radiometer (AVHRR) data from the NOAA-16 satellite data were obtained from the National Oceanic and Atmospheric Administration and identified cloudy conditions at or near the accident site. Cloud-top temperatures in the region varied between -53 degrees C and 6 degrees C. The temperature of -53 degrees C corresponded to heights of approximately 35,000 feet. Due to a temperature inversion in the ABR sounding near 4,000 feet, the temperature of 6 degrees C may correspond to various cloud heights ranging from at or very near the surface to between 3,500 and 6,500 feet. An Area Forecast that included South Dakota was issued at 2045 CDT. The portion of the Area Forecast directed toward the eastern two-thirds of South Dakota forecasted for the accident time: ceiling overcast at 3,000 feet msl with cloud tops to flight level (FL)180, widely scattered light rain showers, and wind from the east at 20 knots with gusts to 30 knots. Prior to the 2045 CDT Area Forecast, another Area Forecast that included South Dakota was issued at 1345 CDT. The portion of the Area Forecast directed toward the central and eastern portions of South Dakota forecasted for the accident time: ceiling overcast at 3,000 feet msl with clouds layered up to FL300, scattered thunderstorms with light rain, cumulonimbus cloud tops to FL400, wind from the southeast at 20 knots with gusts to 35 knots. Airmen's Meteorological Information (AIRMET) SIERRA for IFR conditions was issued at 1959 CDT for a region that included the accident location. AIRMET TANGO for moderate turbulence for altitudes below 15,000 feet was issued at 1545 CDT for a region that included the accident location. The AIRMET also addressed strong surface winds for a region that did not include the accident location. AIRMET ZULU for moderate ice for altitudes between the freezing level and FL200 was issued at 1545 CDT for a region that included the accident location. There were no non-convective Significant Meteorological Information (SIGMET) advisories active for the accident location at the accident time. There were two Convective SIGMETs issued for convection close to the accident location in the two hours prior to the accident time According to the United States Naval Observatory, Astronomical Applications Department Sun and Moon Data, the sunset was recorded at 2037 and the end of civil twilight was 2109. The moon rose at 0615 on the following day. At the time of the accident the wind turbine tower #14 recorded the wind velocity at 9.7 meters per second or 21 miles per hour and the ambient temperature was 7 degrees C. The pilot logged on to the CSC DUAT System on April 26, 2014, at 2141:36 and requested a low altitude weather briefing quick path service. The pilot identified the route of flight as a direct flight between KHRX and 0D8, at an altitude of 8,500 feet. AIDS TO NAVIAGATION The FAA Twin Cities Sectional Chart 87th edition, dated 9 January, 2014, through 26 June, 2014, depicted the city of Highmore, South Dakota, and the Highmore Airport on the southern edge of the chart boundary. The city of Highmore and the airport were both within the same boundary box with a maximum elevation figure of 24 or 2,400 feet msl. The maximum elevation figure immediately south of Highmore was 27 or 2,700 feet msl. An obstacle at an elevation of 276 feet above ground level (agl) and 2,180 feet msl was depicted immediately south of the city of Highmore. A wind farm was depicted south and east of Ree Heights, South Dakota – this wind farm was at an elevation of 420 feet agl and 2,447 feet msl. The wind farm involved in this accident was not depicted on this sectional chart. The FAA Omaha Sectional Chart 89th edition, dated 6 February, 2014, through 24 July, 2014, depicted the city of Highmore, South Dakota, and the Highmore Airport on the northern edge of the chart boundary. The city of Highmore and the airport were both within the same boundary box with a maximum elevation figure of 24 or 2,400 feet msl. The maximum elevation figure immediately south of Highmore was 27 or 2,700 feet msl. A wind farm was depicted south and east of Ree Heights, South Dakota – this wind farm was at an elevation of 420 feet agl and 2,447 feet msl and 420 feet agl and 2,500 feet msl. A single obstruction was depicted on the chart about 7 miles south of the city of Highmore, just to the east of highway 57. The obstruction was at an elevation of 215 feet agl and 2,335 feet msl. A group of obstructions was depicted on the chart about 9 miles south of the city of Highmore, just to the west of highway 57. The obstructions were at an elevation of 316 feet agl and 2,496 feet msl. The wind farm involved in this accident was not depicted on this sectional chart as a wind farm. According to the FAA, the 90th edition of the Omaha Sectional Chart, effective from 24 July, 2014, through 5 February, 2015, added the depiction of the accident wind farm just south of the city of Highmore. This depicted the wind farm west and southwest of highway 57 at an elevation of 2,515 feet msl. In addition, an unlit obstruction at an elevation of 415 feet agl and 2,597 feet msl was depicted just south of the wind farm boundary. There are no instrument approach procedures into 9D0. There are two RNAV (GPS) approaches, runway 13 and runway 31, into 0D8. FLIGHT RECORDERS The accident airplane was equipped with an Apollo GX-50 panel-mount 8-channel GPS receiver. The unit includes a waypoint database with information about airports, VOR, NDB, en route intersections, and special use airspace. Up to 500 custom user-defined waypoints may be stored, as well. The GX-50 is a TSO-C129a class unit capable of supporting IFR non-precision approach operations. Thirty flight plans composed of a linked list of waypoints may be defined and stored. The real-time navigation display can be configured to show: latitude/longitude, bearing, distance to target, ground speed, track angle, desired track, distance, and an internal course deviation indicator (CDI). The unit stores historical position information in volatile memory; however, by design there is no method to download this information. The unit was sent to the NTSB Vehicle Recorders Lab in Washington D.C. for download. Upon arrival at the Vehicle Recorders Laboratory, an exterior examination revealed the unit had sustained significant structural damage. An internal inspection revealed most internal components, including the battery, were dislodged. Since the internal battery was dislodged and the unit relied upon volatile memory to record information, no further recovery efforts were attempted. WRECKAGE AND IMPACT INFORMATION The accident scene was located in level, vegetated terrain, in the middle of a wind turbine farm, about 10 miles south of Highmore, South Dakota. The terrain was vegetated with short and medium grass. The wreckage of the airplane was fragmented and scattered in a radius to the north, through to the west, and then through the south, surrounding the base of wind turbine tower #14. The fragmented pieces of the fuselage, empennage, engine and propeller assembly, and both wings were accounted for in the field of debris. MEDICAL AND PATHOLOGICAL INFORMATION The autopsy was performed by the Sanford Health Pathology Clinic on April 29, 2014, as authorized by the Hyde County Coroner's office. The autopsy concluded that the cause of death was multiple blunt force injuries and the report listed the specific injuries. The FAA's Civil Aerospace Medical In
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.
Source: NTSB Aviation Accident Database
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