Accident Details
On July 25, 2016, at approximately 1050 central daylight time, a Texas Helicopter OH-13H/M74A, registration N10009, sustained substantial damage when it was struck by a passing semi-trailer truck. The incident occurred during reloading operations near Minonk, Illinois. The helicopter was operated by Hendrickson Flying Service of Rochelle, Illinois, under Title 14 Code of Federal Regulations Part 137 as an agricultural application flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight.
The agricultural application nurse truck was stationary and parked on the right shoulder of a paved rural county road, facing west. It was completely clear of the roadway surface, and its hazard lights were activated, according to the loader. The helicopter was positioned on the elevated helipad atop the nurse truck with its engine running and rotor blades turning. The nose of the helicopter faced north, and the tail boom and rotor disk extended approximately 8–10 feet over the road.
Statements
The loader reported that he was in the process of reloading the helicopter's product tanks when a westbound semi-trailer truck drove underneath the rotor disk and struck the tail boom. The impact rotated the helicopter 20–30° from its original position on the helipad, but the helicopter remained upright and on top of the helipad. The right side of the truck's cab and the cargo cover and frame of the trailer were damaged.
The truck driver informed a Federal Aviation Administration (FAA) inspector that he believed he had sufficient clearance to pass safely under the tail rotor. He maintained that the accident was not his fault. When asked why the helicopter was positioned so that the tail boom extended 10 feet over the highway, the pilot explained that parking closer to an adjoining field would cause the platform to tilt, making landing for servicing difficult. The loader stated that, in the future, if loading operations must occur off a well-traveled road, measures would be taken to ensure the tail boom does not overhang the main road.
Inspector's Observations
After examining the accident site, the FAA inspector noted that other flat areas were available in the vicinity but were considered too far from the field being sprayed. The inspector also noted that the tilt mentioned by the pilot would not have been significant nor would it have impeded the highway.