On June 27, 2003, a Hiller UH-12E (registration N62417) was involved in an aviation accident near Elk Mound, WI. Investigators recorded the probable cause as: The pilot's failure to maintain clearance from the terrain. Factors contributing to the accident were the whirlwind, the turbulence, and the helicopter's low altitude. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter impacted terrain after encountering a reported whirlwind during a spraying pass. The pilot stated the aircraft suddenly slammed into the ground and cartwheeled before stopping.
Incident Overview
A helicopter operating as an agricultural spray aircraft impacted terrain after encountering a reported "whirlwind" during a spraying pass. The pilot, who was uninjured according to the source, provided details of the sequence of events.
Pilot Report
The pilot reported that he was on a spray pass at a "good altitude" and at a speed of 55 miles per hour. He noted seeing the whirlwind but was not concerned by it. According to the pilot's statement, "suddenly it felt [he] was slammed into the ground and out of control." The helicopter then cartwheeled approximately 60 to 100 feet before coming to a stop.
Post-Impact Condition
The helicopter came to rest after the cartwheeling motion. The source does not specify the extent of damage to the aircraft or any injuries to the pilot. No further details from the investigation were provided in the source.