History of Flight
On October 5, 2012, at approximately 0758 central daylight time, a Bell 407 helicopter, registration N406AL, was substantially damaged when it collided with terrain shortly after takeoff from Central Industries Airport (2LA0), near Intracoastal City, Louisiana. The commercial pilot, the sole occupant, was fatally injured. The helicopter was registered to and operated by Bristow US LLC under 14 Code of Federal Regulations Part 91 on a company flight plan. Day instrument meteorological conditions (IMC) prevailed for the postmaintenance flight. According to the operator, the pilot was performing the flight to check for residual oil after a routine phase inspection completed the previous evening. At 0756, the pilot activated his local flight plan via electronic message, reporting 1 hour of fuel on board. Several witnesses observed the helicopter start up, enter a low hover over the landing pad, then hover-taxi toward runway 24. One witness saw it depart on the runway heading and disappear into fog or low cloud. Shortly after departure, a sound consistent with ground impact was heard.
Personnel Information
The pilot, age 62, held a commercial pilot certificate with helicopter and instrument helicopter ratings. His last FAA second-class medical certificate was issued on April 18, 2012, with a limitation for corrective lenses. He had accumulated 11,386 total flight hours, including 11,262 hours as pilot-in-command, all in helicopters. He had 619 hours in the Bell 407, 455 hours at night, 279 hours in IMC, and 155 hours in simulated instrument conditions. Since being hired in November 2000, he had 5.0 hours of simulated instrument time, with 0.5 hours in the 12 months prior. He was qualified for Bell 206 and 407, though neither was certified for IFR. His most recent Part 135 proficiency check for the Bell 407 was on February 8, 2012, and for the Bell 206 on August 15, 2012. He flew 446 hours in the past year, 222 in the last 6 months, 118 in 90 days, and 43 in 30 days. He had flown 7 hours in the 24 hours before the accident.
Aircraft Information
The accident helicopter was a Bell 407, serial number 53481, configured for offshore personnel transport. Its type certificate required one pilot and allowed day/night VFR operations. The cockpit had flight attitude instrumentation and avionics, but the helicopter was not IFR certified. It was powered by a Rolls-Royce 250-C47B turboshaft engine, serial number CAE-847752. A normal category airworthiness certificate was issued in June 2001. The helicopter was maintained under an approved inspection program. A routine phase inspection was completed on October 4, 2012, at 11,465.5 total airframe hours. The engine had 7,530.7 hours total time. No outstanding maintenance discrepancies were found in the records.
Meteorological Information
The nearest weather station, Abbeville Chris Crusta Memorial Airport (IYA), 13.6 miles north-northeast, reported at 0755: calm wind, visibility 1/4 mile in fog, overcast ceiling 200 feet, temperature/dew point 20°C, altimeter 30.14 inHg. A witness pilot from the operator reported IMC at 2LA0 before sunrise with low cloud and ground fog. After sunrise, conditions briefly improved, allowing two helicopters to depart VFR, then IMC resumed. When the accident helicopter departed, low cloud, mist, and fog were present. The operator's base manager issued a weather alert for ground fog and zero visibility at 0634, placing all VFR operations on ground hold. At 0713, conditions upgraded to scattered ground fog, allowing VFR under caution. At 0722, another Bell 407 (N687AL) departed VFR with a pilot report of scattered ground fog but clear above. Following the accident, at 0802, the base manager reissued a weather alert for ground fog, requiring pilot consultation, and at 0827, a zero visibility alert ceased all operations. Another operator reported a helicopter that departed about 16 minutes before the accident had visibility down the entire 3,100-foot airstrip, but observed ground fog 75-100 feet thick adjacent to the east side after climbing above the tree line.
Wreckage and Impact Information
All airframe components were located at the accident site. The initial point of impact was in a small group of trees about 132 feet south-southwest of the main wreckage. Two small trees showed limb and trunk damage about 20 feet above ground; a third tree 32 feet into the debris path had damage about 15 feet above ground. The magnetic heading from initial impact to main wreckage was about 035 degrees. A depression attributed to the left toe skid appeared to be the first ground impact. Left float blow-down bottles were found in that depression. Other landing gear components lay between the initial impact and main wreckage. The main wreckage consisted of the fuselage and tailboom, with the fuselage resting on its right side against trees and overgrowth. Flight control continuity could not be established due to multiple separations, all consistent with overstress. Hydraulic control servos moved freely. The transmission, mast, and main rotor hub separated as a unit. Main rotor blades showed bending and delamination from ground impact. The tailboom separated at the fuselage attach point and also forward of the tail rotor gearbox. One tail rotor blade was fractured midspan; the other appeared undamaged. No preimpact failure or malfunction was found in the structure, drive train, flight controls, hydraulic system, or rotor systems. All fractures were from overload during impact. The engine remained attached by oil lines, found vertical with compressor section partially buried. The N1 drive train rotated freely after debris removal. Compressor impeller blades had tips bent opposite rotation. N2 drive train rotated freely. About 1 tablespoon of fuel was collected from the fuel nozzle supply line. The combustion liner was undamaged with normal burn signatures. Magnetic chip detectors were oil-covered and free of foreign material. The engine and ECU were retained for further examination.
Flight Recorders
The helicopter was equipped with an Appareo Flight Data Monitoring system with a crash-hardened recorder, including GPS and attitude reference. It recorded 3-axis accelerometer and GPS data but not airspeed or engine parameters. Data was stored on a non-removable memory device and a removable SD card. The SD card contained records from the accident flight and the previous 98 power cycles. The accident flight data began at 0752:43 and was about 6 minutes long, with about 2 minutes of significant ground movement. The helicopter maneuvered at low altitude until 0756:50, then hover-taxied northeast, turned northwest, then west-southwest, increasing altitude at 0757:55. It took off from runway 24. About 20 seconds later, it reached 255 feet altitude and 51 knots ground speed on the departure heading. It then entered a left descending turn with a maximum bank of 38 degrees and nose-down pitch of 20 degrees, achieving a 1,600 feet per minute descent. The final data point at 0758:30 showed 37 feet altitude, 20 degrees left roll, and 17 degrees nose-down pitch, about 113 feet from the initial impact point and 255 feet from the final wreckage location. At that point, the helicopter had turned about 200 degrees from the runway heading. The non-removable memory device yielded no additional data beyond 0758:30.
Medical and Pathological Information
An autopsy on October 8, 2012, at the Louisiana Forensic Center attributed the pilot's death to multiple blunt-force injuries from the accident. FAA's CAMI performed toxicology tests; carbon monoxide, cyanide, and ethanol were not detected. Pioglitazone and Rosuvastatin were found in blood and liver samples. Pioglitazone (Actos) is an oral antidiabetic agent for type 2 diabetes; Rosuvastatin (Crestor) treats elevated cholesterol. FAA medical records dating to May 1980 showed no disclosure of diabetes or elevated cholesterol, and the pilot did not report any medications on his most recent medical application.
Tests and Research
On November 14, 2012, the engine's electronic control unit (ECU) was examined at the Triumph Engine Control Systems factory. Nonvolatile data analysis showed no malfunctions in the full authority digital engine control (FADEC) at the time of the accident. No unexpected records or incident recorder information were stored, indicating no event triggers were detected during the flight. The manufacturer attributed the lack of recorded faults to a sudden loss of FADEC system power at impact. On February 19, 2013, an engine teardown was completed at the Rolls-Royce factory. Damage to the compressor impeller blades, scoring of the aft impeller face, impeller inducer shroud, and blade tracks of the gas producer and power turbine wheels was consistent with engine operation at impact. Ingested dirt was found throughout the engine airflow path. No mechanical anomalies from a preexisting condition or failure that would have precluded normal operation were identified.