What happened
On August 7, 2025, at approximately 10:59 central daylight time, a Hughes 369D helicopter, registration N173AL, was destroyed during an external load flight near West Alton, Missouri. The aircraft, operated by Excel Helicopters, was performing a Part 133 operation.
ADS-B data indicates the pilot departed from the north bank of the river at approximately 10:25. The flight pattern involved three trips between the north bank and a powerline support tower located on the south bank. The final ADS-B signal was recorded at 10:35.
A witness on a nearby tow vessel observed the pilot and a crewmember attempting to attach an orange safety marker to a power line. During this process, the lineman was standing on the left skid while wearing a safety harness. As the pilot maneuvered the helicopter closer to the lines, the tail of the aircraft struck a power line.
Following the impact, the tailboom partially separated from the airframe. The cockpit then struck the line, creating sparks. The helicopter subsequently fell onto the deck of a barge, where a post-impact fire occurred. The crew of the tow vessel used the vessel's fire station to extinguish the flames. There was no structural damage to the barge or its contents.
The investigation
The wreckage of the helicopter consisted of the fuselage, engine, main rotor transmission, main rotor hub, and the forward section of the tailboom. Fragments of main rotor blades were recovered at distances ranging from 26 to 176 feet from the main wreckage. The aft portion of the tailboom, including the tail rotor and horizontal stabilizer, was not recovered and is presumed to be in the river.
Investigators retained the helicopter wreckage and the video data recorder from the tow vessel for examination. A plan was established to use side-scan sonar to search the river bottom near the accident site.