Accident Summary
On June 6, 2013, at about 1115 central daylight time, a Bell 206-L4 helicopter, registration N720RL, impacted terrain near Abbeville, Louisiana, following a loss of tail rotor effectiveness. The commercial-rated pilot and passenger were not injured, and the helicopter sustained substantial damage. The helicopter was registered to HLW Aviation, LLC and operated by H&M Aviation, Inc., conducting a 14 CFR Part 91 flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Abbeville Chris Crusta Memorial Airport (KIYA) at about 1040.
Pilot Account
According to the pilot, after departing the airport to the southwest, the helicopter approached a canal to pick up water. At an altitude of about 20 feet, the pilot heard a noise followed by a loud "pop." The helicopter then began to spin to the right, and the pilot lost tail rotor authority. After approximately two revolutions, the pilot reduced engine power to idle, and the helicopter impacted terrain and water.
Post-Accident Examination
Examination by the responding Federal Aviation Administration (FAA) inspector revealed that the helicopter had settled into about 3 feet of water. The aft section of the tail boom appeared buckled, and the drive shaft cover was slightly twisted. After recovery, the tail rotor driveshaft cover was removed. Inspection of the driveshaft revealed that the coupling between the driveshaft and the tail rotor gearbox was connected by only one bolt. Of the two bolts, one remained with its associated nut; the other bolt had backed out of the driveshaft but remained in the coupling, with its corresponding nut missing.
Maintenance History
A review of the helicopter's maintenance records showed that it had undergone extensive maintenance, including removal and reinstallation of the tail rotor drive and hub assemblies. The accident flight was the first flight after maintenance and lasted about 0.7 flight hours.