N720RL

Substantial
None

BELL 206-L4S/N: 52027

Accident Details

Date
Thursday, June 6, 2013
NTSB Number
CEN13LA321
Location
Abbeville, LA
Event ID
20130606X65516
Coordinates
29.969293, -92.120765
Aircraft Damage
Substantial
Highest Injury
None
Fatalities
0
Serious Injuries
0
Minor Injuries
0
Uninjured
2
Total Aboard
2

Probable Cause and Findings

Failure of maintenance personnel to ensure adequate torque of a tailrotor drive shaft coupling bolt, which resulted in the partial disconnection of the drive shaft.

Aircraft Information

Registration
N720RL
Make
BELL
Serial Number
52027
Engine Type
Turbo-shaft
Model / ICAO
206-L4B06
Aircraft Type
Rotorcraft
No. of Engines
1

Analysis

On June 6, 2013, about 1115 central daylight time a Bell 206-L4 helicopter, N720RL, impacted terrain, following the loss of tail rotor effectiveness, near Abbeville, Louisiana. 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. under the provisions of 14 Code of Federal Regulations Part 91 flight. Day visual meteorological conditions prevailed for the flight which operated without a flight plan. The flight originated from the Abbeville Chris Crusta Memorial Airport, (KIYA), Abbeville, Louisiana, about 1040.

According to the pilot, he departed the airport to the southwest and approached a canal, to pick up water. At an altitude of about 20 feet, he heard a noise and then a loud "pop". The pilot added, the helicopter then started to spin to the right and that he lost tail rotor authority. After about two revolutions, he reduced the engine power to idle and the helicopter impacted terrain and water.

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, with the drive shaft cover slightly twisted.

After the helicopter was recovered from the water, the tail rotor driveshaft cover was removed. Examination of the drive shaft revealed that the coupling between the drive shaft and tail rotor gear box was only connected by one bolt. Of the drive shaft’s two bolts, one remained with its associated nut; however, the other bolt had backed out of the drive shaft, but remained in the coupling; its corresponding nut was missing.

A review of the helicopter’s maintenance records revealed that the helicopter had undergone extensive maintenance, including removing and reinstalling the tail rotor drive and hub assemblies. The accident flight was the first flight after maintenance and lasted about 0.7 flight hours.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN13LA321