- Date
- March 2, 2009, 07:20 local (12:20 UTC)
- Place
- Galliano, LA
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Standing
- Aircraft
- N410RLBell 206
- Defining event
- Standing-engine(s) operating: Flight control sys malf/fail
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 28, 2009
- Report
- Approved by Office Director
- NTSB office
- Central Region
- Parties
- FAA/FSDO
- FAA report
- 20090302002519A
- Case key
- 73466
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The failure of the tail rotor driveshaft and coupling during engine start due to the mechanic's failure to properly reattach the tail rotor driveshaft and coupling during maintenance.
Findings · 1
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The commercial pilot was starting the single-engine helicopter's engine when he heard a loud bang and vibration. He immediately shut down the engine and exited the helicopter. Examination of the helicopter revealed that the tail rotor driveshaft and coupling had severed just forward of the gearbox, which resulted in substantial damage to the tail boom. The helicopter had undergone recent maintenance to the tail rotor gearbox input seal which included the removal of the tail rotor drive shaft from the coupling. When the two components were reattached, the mechanic only hand-tightened the bolts, figuring additional maintenance was still planned for the gearbox. He then installed the tail rotor drive shaft shaft cover. The mechanic moved on to another project and did not make a logbook entry of the work that he had completed or that the bolts were only hand-tightened. Another mechanic later performed additional maintenance to the gearbox, but the bolts were not checked since the maintenance manual did not require the removal of the tail rotor driveshaft cover. A .2-hour maintenance flight check was conducted and the helicopter was returned to service. The accident occurred on first engine start after it had been returned to service.
Factual narrative
On March 2, 2009, at 0720 central daylight time, a Bell 206L-3, N401RL, was damaged when the tail rotor drive shaft and coupling severed while the helicopter was sitting on the ramp with the engine running. The helicopter was operated by and registered to Rotorcraft Leasing Company, LLC, Broussard, Louisiana. The commercial pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the ferry flight conducted under 14 Code of Federal Regulations Part 91. According to the operator, the pilot heard a loud bang and vibration shortly after starting the engine. He immediately shut down the engine, and exited the helicopter. Examination of the helicopter revealed that the tail rotor drive shaft and coupling had severed just forward of the gearbox, which resulted in substantial damage to the tail boom. The helicopter had undergone recent maintenance to the tail rotor gearbox input seal which included the removal of the tail rotor drive shaft from the coupling. When the two components were reattached, the mechanic only hand tightened the bolts, figuring additional maintenance was still planned for the gearbox. He then installed the tailrotor drive shaft cover. The mechanic moved onto another project and did not make a logbook entry of the work that he had completed or that the bolts were only hand tightened. Another mechanic later performed additional maintenance to the gearbox, but the bolts were not checked since the maintenance manual did not require the removal of the tail rotor driveshaft cover. A .2-hour maintenance flight check was conducted and the helicopter was returned to service. The accident occurred on first engine start after it had been returned to service.
Aircraft
- Registration
- N410RL
- Reported as
- Bell 206 (L4)
- Category
- Helicopter
- Airframe hours
- 5,118
- Engine
- Rolls Royce 260c30, 850 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Ferry · Part 91
- Operator
- Rotorcraft Leasing Company, LLC
- Registered owner
- Rotorcraft Leasing Company, LLC
- Airworthiness certificate
- Standard, Transport
- Last inspection
- AAIP · February 15, 2009
- Departed
- GAO · Galliano, LA
- Destination
- GAO · Galliano, LA
- Flight plan
- Unknown
- Airport
- GAO · South Lafourche Leonard Miller
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 32
- Injuries
- None
- Certificate
- Commercial
- Instrument ratings
- Helicopter
- Medical
- Class 2, Without waivers/limitations
- Last flight review
- October 20, 2008
- Seat
- Right
- Flight hours
- 1,292 total · 81 in this make and model · 1,250 as pilot in command · 36 in the last 90 days · 15 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Variable at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 30 °F, dew point 30 °F
- Observed at
- GAO
Docket · 3
The files NTSB released with the investigation on May 29, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 15.3 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.