History of Flight
On May 12, 2011, about 1517 central daylight time, a Bell OH-58C helicopter, registration N9263Y, impacted terrain during an aerial application flight near New Athens, Illinois. The helicopter was registered to and operated by Couch Helicopter Service, Inc., Walcott, Arkansas, under 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from New Athens, Illinois, at an unconfirmed time.
The helicopter was used to spray fungicide on a wheat field. According to the operator, the pilot would land on a support truck platform in the farm field for refilling chemicals and fueling while the engine remained running. The pilot had completed twelve such cycles and was proceeding back to the field when the accident occurred.
Two employees witnessed the accident. One reported that after the helicopter lifted off the truck and climbed westward, it passed over a rise, then a loud noise was heard. He saw the tail rotor separate and the helicopter spin about the rotor shaft axis. The second employee also heard a sound and saw the tail boom missing; the helicopter spun at least five times before it went behind a rise. Both witnesses responded, extricated the pilot, and began CPR until emergency medical services arrived.
Personnel Information
The pilot held a commercial pilot certificate with single- and multi-engine land, helicopter, and instrument ratings. He was issued a second-class medical certificate on June 9, 2010, with no restrictions. His flight logbook was not recovered, but he reported 23,000 hours of flight experience on his most recent medical certificate application.
Aircraft Information
The helicopter was originally a U.S. military Bell OH-58C, serial number 69-16239, operating under Rotorcraft Development Corporation Type Certificate R00006DE as a restricted category military surplus helicopter. It was a single main rotor design with an anti-torque tail rotor on an aft boom, powered by a 420-horsepower Rolls-Royce T63-A720 engine, serial number AE-405191.
Maintenance records showed an annual inspection on June 14, 2010, and a 100-hour inspection on April 28, 2011. At the accident, the helicopter had an estimated total time of 12,694.6 hours. It was equipped with a spray boom system and chemical hopper.
Meteorological Information
The weather observation from Scott Air Force Base/Mid America Airport, about 13 nautical miles north, recorded at 1455: wind from 220 degrees at 10 knots, visibility 10 miles, clear sky, temperature 30°C, dew point 15°C, altimeter 29.85 inches of mercury.
Wreckage and Impact Information
The helicopter came to rest upright on a rolling wheat field. The main wreckage was about 250 feet west of depressions with spray nozzles. The tail rotor and aft tail boom were found between the nozzles and main wreckage. Tail rotor blades were intact and rotated freely. A tail rotor driveshaft cover had diagonal impact marks consistent with main rotor blade contact. One main rotor blade showed black paint transfer and was fractured; the other had trailing edge buckling. The fuselage was nearly broken in two at the rear passenger door area. The engine exhibited no preimpact defects; rotational scoring and metal splatter indicated engine operation at impact. Control continuity was confirmed except for side-to-side cyclic movement due to cockpit damage, and tail rotor pedal continuity could not be determined. All damage was consistent with impact, and no preimpact deficiencies were found. The tail boom separation was consistent with main rotor blade impact.
Medical and Pathological Information
An autopsy attributed the pilot's death to blunt trauma to the chest received in the accident. Toxicology testing detected 217.6 ug/ml of acetaminophen in urine.
Tests and Research
Data from the Ag-Nav GPS receiver showed the last flight segment lasted 22.6 seconds. The helicopter took off from the support truck, traveled west, accelerating to about 52 mph. GPS altitude remained nearly constant, varying by 6 feet, with the lowest recorded altitude of 325 feet. Topographic data indicated ground elevation between 410 and 420 feet.