What happened
On June 9, 2018, a Robinson R44 helicopter, registration N529DW, was performing Part 135 aerial photography operations for a boating event on Lake Winnebago. After completing a 1.5-hour flight over various waterways and dropping off a photographer at a field near the Fox River, the pilot departed to fly to Wittman Field (OSH) for refueling.
While flying northwest, the helicopter struck the top two lines of an unmarked five-line array—consisting of a static wire and a fiber optic line—that spanned the Fox River. The lines were positioned approximately 100 feet above the water. Surveillance footage and witnesses observed the aircraft pitch up upon impact, at which point the tail rotor separated from the airframe. The helicopter then descended into the river. The pilot sustained 1 fatal injury due to drowning and blunt force trauma.
The investigation
Investigators examined the wreckage, which was recovered from the river approximately 300 feet from the initial wire strike. The impact caused significant damage to the entire structure, including a crushed cockpit and a missing left canopy section. While the main rotor blades remained attached, a 180-foot section of 7-strand steel cable was found wrapped around the main rotor hub and both blades, causing cuts to the blades.
The tail rotor assembly, including the tail boom, drive shaft, and push-pull tube, fractured approximately 4 feet aft of the forward flex plate. The tail rotor itself separated from the aircraft and was not recovered. Mechanical examination of the airframe showed no evidence of malfunctions or failures that would have prevented normal operation. Toxicology results for the pilot were negative for drugs, alcohol, carbon monoxide, and cyanide.