Overview
A helicopter was operating above a radio tower while a worker on the tower attached a 50-foot line from the helicopter to an antenna. During the maneuver, the helicopter settled, and the main rotor blades collided with the antenna and its mounting pole. The main rotor separated from the helicopter, which then descended uncontrolled until impact with the ground.
Injuries and Damage
The worker on the tower sustained a broken left ankle when the helicopter struck the antenna. The helicopter sustained substantial damage due to the collision and subsequent ground impact.
Pilot Toxicology
Toxicology tests performed on specimens from the pilot revealed the presence of diphenhydramine: 0.214 mcg/ml in blood, 0.597 mcg/ml in liver fluid, and diphenhydramine detected in urine. Diphenhydramine is an antihistamine with sedative effects.
Operator and Equipment Records
FAA records indicated the helicopter operator held a Title 14 CFR Part 137 Aerial Application Certificate. However, there was no record that the operator held a 14 CFR Part 133 External Load Certificate. Additionally, the helicopter's logbook contained no record of an FAA Form 337 (Major Repair and Alteration) for installation of the external load hook. This hook had reportedly been installed by the pilot approximately one week before the accident.
Weather Conditions
The wind at the time of the accident was reported as steady at about 15 mph, with no gusts.