NTSB Factual Report

HISTORY OF FLIGHT

On July 5, 2005, at 0826 central daylight time, a Rockwell S-2R, N3211R, operated by Dakota Air Spray, collided with transmission lines during an aerial application flight approximately 12 miles south of Bristol, South Dakota. The commercial pilot was fatally injured. The airplane was substantially damaged. The Title 14 Code of Federal Regulations Part 137 aerial application flight was operating in visual meteorological conditions without a flight plan. The flight originated from a private airstrip in Bristol, South Dakota, about 0805.

A witness to the accident reported seeing the airplane flying to the north-northeast, almost paralleling the power lines. The airplane then made a turn and contacted the power lines. The witness reported seeing the airplane in a left bank, but was not sure if the bank occurred prior to or after the airplane contacted the power lines. The airplane then descended to the ground.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with a single-engine land rating. This certificate contained the limitation, "Carrying passengers in airplanes for hire is prohibited at night and on cross country flights of more than 50 nautical miles."

The pilot's most recent medical certificate was issued on April 19, 2005. The medical certificate contained the limitation, "Shall wear corrective lenses for near and far vision." According to Federal Aviation Administration (FAA) records, the pilot reported having 7,100 hours of flight time as of the date of his most recent medical examination, 20 hours of which were accumulated in the previous 6 months.

According to FAA records, the pilot's commercial pilot certificate was suspended for 30 days in 1997 for another accident in which he contacted power lines. This accident is addressed in National Transportation Safety Board report CHI97LA124.

The president of Dakota Air Spray stated the pilot lived his entire life in the Bristol area and he was very familiar with the location of the power lines.

AIRCRAFT INFORMATION

The airplane was a low-wing single, single-engine, single-place restricted category airplane used for aerial application. The airplane was equipped with a Pratt and Whitney Canada PT6A-15AG engine. Logbook records indicate the last annual inspection of the airplane was completed on March 18, 2005, at a total aircraft time of 5,933.1 hours and a tachometer time of 893.1 hours.

METEOROLOGICAL INFORMATION

The weather reporting station located at Aberdeen Regional Airport (ABR), Aberdeen, South Dakota, approximately 35 nautical miles northwest of the accident site, listed the conditions at 0853 as: Wind - 060 degrees at 4 knots; Visibility - 10 statute miles; Sky Condition - Clear; Temperature - 16 degrees Celsius; Dew Point - 12 degrees Celsius; Altimeter Setting - 30.15 inches of Mercury.

WRECKAGE AND IMPACT INFORMATION

The FAA conducted an on-scene examination of the accident site. The static lines that were contacted were part of the Basin Electric Power System. These lines generally travel from northwest to southeast in the area of the accident. The lines are strung between steel towers that are approximately 100 feet in height. Each tower has two static lines that are strung along the tops of the towers, each supported by its own arm of the tower. There are three main transmission lines running between the towers that are located below the static lines. The static lines that were separated were on the southeast side of tower number 24-373. One of the lines was severed and the other was disconnected at the tower. One of the static line arms on tower 24-373 was visibly bent. The Day County Sheriff's Office reported that the impact with the wires resulted in damage to the static line arms on 13 other towers.

The airplane came to rest inverted in a slough approximately 30 to 40 yards north-northwest of the power lines. The outboard section of the right wing was bent downward and the right wing section of the spray boom was separated from the airplane. One propeller blade contained a leading edge gouges similar in diameter to the static line. The right main gear was separated from the airplane and was located near the tower 24-373. The gear strut contained a series of impressions indicative of it having contacted the static line.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted on the pilot by LCM Pathologists, P.C., Sioux Falls, South Dakota, on July 6, 2005.

Toxicological tests on the pilot were conducted by the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma. The results were negative for all tests performed.

ADDITIONAL INFORMATION

The FAA was a party to the investigation.

NTSB Probable Cause

The pilot's failure to maintain clearance with the static lines between the transmission towers. A factor associated with the accident were the static lines.