History of Flight
On May 28, 2014, about 1015 central daylight time, a Texas Helicopter Corp OH-13H/M74A agricultural helicopter, N51853, registered to the pilot, sustained substantial damage after colliding with trees and a building near Little Falls, Minnesota. The commercial pilot was seriously injured in the accident, was hospitalized, and succumbed to those injuries eight days later on June 5, 2014. The aerial application flight was conducted under 14 Code of Federal Regulations Part 137. No flight plan was filed, and visual meteorological conditions prevailed. The flight originated at 0945 from a nearby private agricultural staging area.
A witness traveling on a nearby highway observed the helicopter cross the highway and head toward farm buildings bordering a large field that the helicopter was spraying. The witness reported that when the helicopter was about three-quarters down the field, it seemed to "hop" as if encountering rising air, then veered to the right. The helicopter pulled up to about twice the height of nearby trees and began rapidly spinning. The witness lost sight when their vehicle passed trees, then saw smoke from one of the farm buildings.
The chemical truck operator stated they were staging about half a mile from the field. He noted no issues with the pilot or helicopter that day and said the pilot should have been nearly done treating the field. The pilot was spraying in a direction toward the farm buildings.
At 0944, the pilot contacted Miller Army Air Field advisory frequency, advising he would be spraying a field northeast of the airfield below 100 ft for about an hour. The controller informed him of an active restricted area, wind 040 degrees at 5 knots, and altimeter 30.11 inches.
Local law enforcement found the helicopter impacted into the roof of an all-metal pole shed. The pilot was strapped in his seat, unconscious but breathing, and was transported by helicopter to St. Cloud, Minnesota.
Personnel Information
The pilot, age 71, held a commercial pilot certificate with airplane, single-engine land, and rotorcraft helicopter ratings. His logbook recorded approximately 17,370 total flying hours and 4,500 hours in the accident make and model, with 25 hours in the preceding 90 days. He completed a flight review on April 1, 2013, and held a valid second-class medical certificate dated March 24, 2014, with a limitation for corrective lenses.
Aircraft Information
The helicopter was a Texas Helicopter Corp OH-13H/M74A, serial number 78-021, manufactured in 1978. It had a restricted special airworthiness certificate for agricultural pest control, dated May 17, 2000. It was powered by one Lycoming VO-435-A1F fuel-injected reciprocating engine, rated at 260 horsepower. The helicopter underwent a 100-hour/annual inspection on May 2, 2014, at a total time of 7,686.0 hours. The hour meter at the accident indicated 2,445.7 hours.
Meteorological Information
At 0959, the routine aviation weather observation at Little Falls, Minnesota, 10 miles south of the accident site, recorded wind 100 degrees at 3 knots, clear skies, 10 statute miles visibility, temperature 66°F, dew point 43°F, and altimeter 30.09 inches Hg.
Wreckage and Impact Information
The debris path began with a large tree 70 yards east-southeast of the main wreckage, where part of a tail rotor blade and cut branches were found. Cut branches led west toward the farm buildings. The main wreckage, including cabin, fuselage, tail boom, main rotor system, and most of the tail rotor, was embedded in the roof of a metal pole shed. The tail boom and tail rotor rested against the east wall. The main rotor separated from the transmission and rested in a nearby tree. Flight control continuity was confirmed. Post-removal examination of the engine, transmission, and other systems revealed no pre-impact anomalies.
Medical and Pathological Information
The pilot died eight days after the accident. An autopsy performed on June 6, 2014, by the Ramsey County Medical Examiner determined the cause of death as complications of a closed head injury due to a helicopter crash. Toxicological tests detected drugs that were the result of life-saving treatment: atropine, doxazosin, lorazepam, and morphine.