Bell 407 accident near Pecan Island, Louisiana, June 8, 2015
On June 8, 2015 at about 7:32 pm local time, a 1999 Bell 407 (helicopter), registered N501PH, was substantially damaged in an accident during enroute (cruise) near Pecan Island, Louisiana. It was flown under charter and air-taxi rules (Part 135). No one was hurt; 5 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The fatigue fracture of the tail rotor gearbox attachment studs, which resulted in a loss of tail rotor control and a subsequent hard landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 8, 2015 · about 7:32 pm local time
- Place
- Pecan Island, Louisiana · map
- Type
- Accident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 407, built 1999 · all 407s on the register
- Registration
- N501PH · no longer on the register · serial 53401
- Damage
- Substantial damage
- Flight
- Flight · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The operator reported that the helicopter air taxi flight was in cruise about 1,000 ft above ground level when the pilot felt an impact and a strong vibration. The pilot completed an instrument and functional control check and could not immediately identify any anomalies. The pilot stated that, as he slowed the helicopter for landing, he noticed a "heavy mechanical sound and strong vibration." The vibration worsened, and the pilot began to have difficulty controlling the helicopter; he subsequently initiated an autorotation and deployed the helicopter's floats. The helicopter touched down in a marshy area, and the pilot and passengers egressed. During the landing, the main rotor blades contacted the tail boom and one of the tail rotor blades, resulting in separation of the tail rotor gearbox (TRGB) support structure, which was subsequently located in the marsh. A postaccident examination and metallurgical analysis revealed that fatigue fractures on two of the four TRGB attachment studs likely existed before the accident flight. As the fatigue fractures grew larger through the first two attachment studs, their load-carrying capability lessened, and the additional load was transferred to the remaining attachment studs. The progressive failure of the fatigued TRGB attachment studs led to the vibrations felt by the pilot and, ultimately, the uncommanded right yaw and subsequent loss of tail rotor control. The reverse- bending, high-cycle fatigue fracture initiation mode observed on two of the TRGB studs suggests the fatigue fractures were a result of a loss of torque of the attachment stud nuts. The reason for the loss of torque could not be determined based on the available information.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Flight control sys malf/fail during enroute (cruise) defining event
- Autorotation Hard landing
- Autorotation Off-field or emergency landing
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Attain/maintain not possible
- cause Aircraft › Aircraft propeller/rotor › Tail rotor › Tail rotor blade › Failure
- cause Aircraft › Aircraft propeller/rotor › Tail rotor › (general) › Fatigue/wear/corrosion
- cause Aircraft › Aircraft propeller/rotor › Tail rotor › (general) › Damaged/degraded
- cause Aircraft › Aircraft propeller/rotor › Tail rotor › (general) › Capability exceeded
- Environmental issues › Physical environment › Terrain › Rough terrain › Contributed to outcome
- Environmental issues › Physical environment › Terrain › Water › Contributed to outcome
Pilot
- Certificate: airline transport pilot, flight instructor
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,959 hours in all; 829 in this make and model; 20 in the last 30 days; 2,155 as pilot in command; 1,051 on instruments
- Last flight review: July 13, 2014
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 16,638 hours
- Last inspection: approved inspection programme, August 7, 2014
- Maximum gross weight: 5,250 lb
- Landing gear: fixed
- Engine: Allison 250-C47B (turboshaft); 1,430 hours total
- Operator: Phi INC
The flight
- Departed from: Vermilion Block GM
- Destination: Pecan Island LA
Weather at the time
- Light: daylight
- Wind: from 140° at 8 knots
- Visibility: 10 statute miles
- Sky: scat at 10,000 ft
- Temperature: 84°F (29°C), dew point 73°F (23°C)
- Altimeter: 29.97 inHg
- Observation at 7:53 pm from KARA, 35 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 4 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N501PH the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.