N690WR
Eurocopter France EC120B
Personnel on the offshore oil platform reported hearing the helicopter approaching the platform to land. They then felt the platform shake at which time the helicopter engine noise stopped. One witness reported that prior to this the engine sounded normal. They stated they went outside and saw debris in the water on the north side of the platform, damage to the flare boom, and debris scattered on the platform. The helicopter and its occupants were later located and recovered from 101 feet of water, approximately 2,900 feet from the platform. The personnel reported the winds were out of the south at 20 to 25 knots when the accident occurred. The platform is oriented north/south with the helipad located on the south end of the platform. Two flare booms extend out over the water from the raised structure at the north end of the platform. These flare booms are approximately 100 feet in length. The flare booms, which are angled out toward the northwest and northeast corners of the platform, are angled up approximately 40-degrees. The helicopter contacted the flare boom located on the northwest corner of the platform. Examination of the helicopter and engine failed to reveal any mechanical failure/malfunction, which would have resulted in the accident. Data recorded in the Vehicle Engine Multifunction Display revealed recorded faults, which were associated with post impact system failures. The pilot had been flying off shore operations for approximately seven months prior to the accident.
HISTORY OF FLIGHT On February 12, 2007, at 0811 central standard time, a single-engine turbine powered Eurocopter EC120B, N690WR, operated by ERA Helicopters LLC, was substantially damaged when it contacted an offshore oil production platform, Vermillion 200A, located in the Gulf of Mexico. The helicopter was approaching the platform to land when the accident occurred. The commercial pilot and passenger were fatally injured. Visual meteorological conditions prevailed and a company flight plan was filed. The flight was operating under 14 Code of Federal Regulations Part 135 at the time of the accident. The flight originated from Vermillion 199 at 0807, with the intended destination of Vermillion 200A. Vermillion 199 is located approximately 4 statute miles southwest of Vermillion 200A. The last radio transmission between the pilot and dispatch was when the pilot reported departing Vermillion 199 and that he had 1.4 hours of fuel on board. Personnel on Vermillion 200A reported the pilot made a radio call stating that he was approaching the platform for landing. They stated they heard the helicopter, then they felt the platform shake. One person stated the helicopter sounded normal until the platform shook at which time the engine noise stopped. They stated they went outside and saw debris in the water on the north side of the platform. They also noted debris on the platform and damage to the flare boom at the north west side of the platform. None of the personnel saw the helicopter prior to the impact. The personnel reported the winds were out of the south at 20 to 25 knots when the accident occurred. The helipad is located on the south end of the platform. PERSONNEL INFORMATION The pilot, age 46, held a commercial pilot certificate with helicopter and instrument helicopter ratings. He also held a flight instructor certificate with helicopter and instrument helicopter ratings. The flight instructor certificate was last renewed on March 18, 2006. The pilot was issued a second-class medical certificate on July 10, 2006. The medical certificate contained the limitation, "Must wear and possess correcting lenses for distant and near vision." According to records supplied by ERA Helicopters LLC, the pilot had a total helicopter flight time of 1,434 hours, of which 1,368 hours were as pilot-in-command. The pilot's total flight time in an EC120 was approximately 171 hours. The pilot did not have any EC120 experience prior being hired by ERA on July 17, 2006. The pilot was currently working a 21-day on, 21-day off duty schedule. He was stationed on the Vermillion 200A platform during the days he was on duty. The pilot's last duty rotation began on January 25, 2007. On the day of the accident the pilot departed Vermillion 200A at 0709 and flew to two other platforms prior to returning to Vermillion 200A, which is when the accident occurred. His total flight time for that day was 28 minutes. AIRCRAFT INFORMATION The accident helicopter was a 1999 Eurocopter EC120B, serial number 1059. It was a multi-purpose, single-engine, five-seat helicopter. On February 10, 2007, the helicopter was flown to the ERA facility near Morgan City, Louisiana, where it underwent a scheduled airworthiness check. The total aircraft time listed at the inspection was 6,027.2 hours. The total aircraft time at the time of the accident was 6,030.8 hours. The helicopter was not equipped with dual controls at the time of the accident. Items listed on the Airworthiness Checklist included "Check emergency float bottle for correct pressure indication", and "Inspect emergency float hoses and fittings for chafing, condition, and security." The helicopter was equipped with a Turbomeca Arrius 2F engine, serial number 34041, which supplied 432 shaft horsepower. This engine was installed on N690WR on July 7, 2006, at an engine total time of 3,295 hours. Records from the Airworthiness Inspection on February 10, 2007 indicated the engine had a total time of 3,711.3 hours, the gas generator had a total time of 6,228.64 cycles, and the power turbine had a total time of 6,778.05 cycles. According to ERA, the helicopter was generally based off shore on Vermillion 200A where it normally would stay for five nights prior to coming back to shore for maintenance. METEOROLOGICAL INFORMATION The closest weather reporting facility was on the South Marsh 107 platform, located approximately 41 miles southeast of Vermillion 200A. At 0920, the weather was recorded as: visibility 10 miles, clear skies, winds 165 degrees at 20 knots gusting to 25 knots. HELIPAD INFORMATION Vermillion 200A is located approximately 60 miles on the 185-degree radial from the White Lake Very High Frequency Omnidirectional Range (VOR). The VOR is located near Pecan Island, Louisiana. The platform is primarily two levels with raised structure above the upper level on both ends of the platform. The upper level of the platform is approximately 120 feet above the water. The helipad is located on top of the raised structure at the southern end of the platform. The helipad is approximately 20 feet above the upper level of the platform. Two flare booms extend out over the water from the raised structure on the north end of the platform. These flare booms are approximately 100 feet in length. The flare booms, which are angled out toward the northwest and northeast corners of the platform, are angled up approximately 40-degrees. A flare boom is a tubular structure with an associated catwalk, which is used to burn off natural gas waste during the oil production process. The flare boom that was contacted was on the northwest corner of the platform. WRECKAGE AND IMPACT INFORMATION The wreckage was located at a water depth of 101 feet, approximately 2,900 feet from Vermillion 200A. The wreckage was recovered from the water at 2352 and was transported to a storage facility in Morgan City, Louisiana. Platform Inspection of Vermillion 200A revealed the helicopter contacted the flare boom on the northwest corner of the platform. Scrapes, dents, and gray and blue paint transfers were visible on both the boom and the catwalk at a location that was approximately two-thirds the way up the flare boom from the platform. A light on the end of the flare boom was broken and honeycomb material identified as being from the helicopter's fenestron was found on the flare boom. Scrapes, dents, paint transfers, and a broken light were also found on the elevated structure on the east side of the platform. Pieces of the main rotor blade and several main rotor blade tip weights were found scattered primarily on the northeast side of the platform. Wires were also located on the platform, which were identified as being from the helicopter's tail position light. Main Wreckage The top of the cabin was crushed downward and although damaged, the floor was intact. The instrument panel including the Vehicle Engine Multifunction Display (VEMD) were cut away from the main wreckage during the wreckage recovery from the water. These components were then recovered from the water approximately one week later, after the wreckage examination. The cockpit flight controls remained in their respective positions. The windscreen, doors, and door panel were separated. The right skid was separated at the aft attach point. The left skid was intact. The cyclic control was intact and continuity was established from the cockpit up to the mast. The throttle twist grip was seized in the fly position. The collective control moved freely throughout its full range with no resulting movement in the swashplate. The rivets which connected the torque tube to its control output lever under the left side floorboard had sheared. Continuity was established from the break rearward to the swash plate. The anti-torques pedals were jammed in the full left pedal input position. The tail rotor flex ball cable was separated near the tailboom separation. Control continuity was established up to the point of the tailboom separation. The tailboom was separated near the fuselage/tailboom transition area. The fenestron gearbox and fenestron blades were separated and missing. The tailboom was separated into several pieces and the fenestron was separated from the tailboom. Rectangular puncture holes were visible in the tailboom skin. These holes matched the size and shape of the main rotor blade tip weights. Yellow and red paint transfers were visible on the left side of the tailboom. The separated portion of the tailboom contained an impact mark indicative of a main rotor blade strike. The lower half of the fenestron was separated into several pieces. Rotational scoring was visible on the upper left portion of the fenestron shroud. A series of uniformly spaced scratches was visible on the outside surface of the fenestron. Five rectangular shaped entrance holes were visible on the right side of the fenestron. The corresponding exit holes were visible on the left side of the fenestron. These holes matched the shape and size of the main rotor blade tip weights. The fuel shutoff valve was in the open position. All of the circuit breakers were in except for the strobe light circuit breaker. The hydraulic switch on the collective was in the normal, guarded position, and the hydraulic system components were intact. Main Rotor The main rotor brake was not engaged. The red blade was separated approximately 24 inches from the root of the blade. The blue blade was separated approximately 36 inches from the blade root. The yellow blade tip was missing and the blade was cracked about 18 inches from the blade root. The yellow blade contained a 7mm indentation near the tip of the blade. A piece of a main rotor blade leading edge was located on the platform. This piece contained yellow paint transfer marks. All of the main rotor control assembly components were intact. Transmission and Engine The transmission coupling shaft exhibited a torsional separation approximately 10 inches aft of its forward flange. The direction of twist at the separation was consistent with sudden main rotor stoppage. The aft end of the transmission shaft was intact and connected. The shaft was free to move in the free wheel direction, but could not be moved in the drive direction. The main transmission and hydraulic magnetic chip plugs were clean. The fuel and oil pre-blockage indicators were not in the bypass position. The rear engine mounts were twisted and broken. The compressor was seized. All of the power turbine blades had been shed and had exited through the exhaust duct, which contained numerous dents on its interior surface. The bottom right side of the exhaust duct was crushed inward. The fuel and oil filters were clean. Fuel and oil were present in their respective filter cavities. The oil system magnetic chip plugs were clean. The fuel flow pointer and the anticipator pointer were positioned at 50 and 35 degrees, respectively. Both the fuel flow and anticipator cables and connections were bent and pulled. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy of the pilot was performed by the Lafayette Parish Coroner's Office on February 15, 2007. The final autopsy report listed the cause of death as "multiple blunt force trauma." The FAA's Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot. All test results were negative. SURVIVAL ASPECTS The pilot and passenger were both reportedly located strapped in their seats and the seat belts were cut during extrication. The helicopter was equipped with attenuating seats. The left front seat pan showed deformation to the right and the seat pan was buckled in the center. The right front seat pan was also crushed. The float activation lever in the cockpit was pulled back and bent to the right. The left skid float was partially inflated. The right skid float was not inflated. The forward air supply line attachment nut was found loose. The life raft was stowed in its pack and two life vests were found floating on the surface of the water after the impact. TESTS AND RESEARCH The Vehicle Engine Multifunction Display (VEMD), Sextant Model number F9111, is a device that displays engine and aircraft parameters during flight and records information for maintenance purposes. The VEMD is located on the instrument panel and contains two calculation modules, lane 1 and lane 2, and a screen module. The VEMD begins recording specific failures and exceedences as soon as the helicopter's electrical system is functional. The VEMD was shipped to Thales Avionics, Inc., where the data was downloaded. The data was then sent to the Bureau d'Enquetes et d'Analyses our la Securite de l'Aviation civile (BEA) in France for further analysis. The data revealed the accident flight was designated as number 2916 and that the flight report was not completed, indicating that the flight did not end normally. According to the data, 25 failures were detected and recorded by the VEMD at 5 minutes (mn) 17.00 seconds (s) lapsed time. According to Eurocopter, these failures were most likely associated with the impact and subsequent power supply loss. Six other failures were also recorded. One of the six, SURV_DOM_FF_RT (71), is associated with the fuel flow temperature sensor. This failure was recorded on all the previous flights which had data stored in the VEMD. The other failures SURV_DOM_TRQ (54), SURV_ALIM_OTHER1 (14), CROSS_BATC (84) and SURV_DOM_T4 (70) were recorded between 5mn 21.50s and 5 mn 25.50s, after the initial 25 failures. According to Eurocopter the last four failures are defined as: SURV_DOM_TRQ (54): "Torque value domain checking." This code appears as soon as the first value of over torque is detected. For the EC120 VEMD, the first value of over torque is 110 percent. SURV_ALIM_OTHER1 (14): "Test of ASIC IOM value." ASIC = Application Specific Integrated Circuit; IOM = In Out Module. That means: "checking of VEMD voltage alimentation (5v&[plus/minus]15v)." In this case, with the associated parameters, a default on the voltage value generated this code. CROSS_BATC (84): "Dissimilarity check between BATC value acquired by a module and value received through the crosstalk." BATC = Current of the Battery. That means that the system detected an anomaly at the battery current level. SURV_DOM_T4 (70): "T4 [turbine] value domain checking." This code appears as soon as the first value of high T4 temperature is detected. For the EC120 VEMD, the first value of abnormal temperature is 840 degrees C.
The pilot's inadequate compensation for the gusty wind conditions which resulted in his failure to maintain clearance with the structure extending from the offshore oil platform. Contributing to the accident was the gusty wind condition.
Source: NTSB Aviation Accident Database
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