Aviation Accident Summaries

Aviation Accident Summary FTW04FA186

Cameron, LA, USA

Aircraft #1

N1078C

Bell 206 L-1

Analysis

The 18,056-hour pilot made a mayday distress call on the common traffic advisory frequency stating that "he was going down." No further radio transmissions were received from the pilot. The helicopter impacted the water about 8 miles short of it intended destination. The positioning flight was scheduled from an offshore oil platform to the company's on-shore operations base. Signatures of the recovered wreckage were consistent with an uncontrolled impact with the water. There were no reported eyewitnesses to the accident, and no significant weather was reported in the area at the time of the accident. No mechanical anomalies were found with the airframe or the engine during the course of the investigation. The engine teardown examination at the engine manufacturer's factory did not reveal any anomalies that could have prevented normal operations. Several helicopter components and parts were further examined at the helicopter manufacturer's laboratory. No anomalies or pre-existing faults were found with any of the examined parts.

Factual Information

HISTORY OF FLIGHT On July 17, 2004, approximately 0930 central daylight time (CDT), a Bell 206L-1 single-engine turbine powered helicopter, N1078C, registered to and operated by Rotorcraft Leasing Company L.L.C. (RLC) of Broussard, Louisiana, as Apache 51, was destroyed when it impacted water in the Gulf of Mexico during a forced landing near Cameron, Louisiana. The airline transport rated pilot, sole occupant of the helicopter, was fatally injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 positioning flight. The flight originated from the offshore platform West Cameron (WC) 645 at 0838, and was destined for the company's Cameron onshore operations base (CAM), near Cameron, Louisiana. On the first flight of the day on July 17, 2004, the pilot departed CAM at 0643 and arrived at High Island (HI) 350 at 0745. Apache 51 departed HI 350 at 0755 and arrived at WC 544 at 0804, where the helicopter was refueled. The pilot reported the fuel-on-board to be 2 hours and 30 minutes, with an estimated time of arrival at CAM to be 0940. At 0814, Apache 51 departed WC 544 for WC 645. Apache 51 arrived at WC 645 at 0830. At 0838, Apache 51 departed WC 645, reporting two hours of fuel-on-board and a distance of 105 nautical miles to CAM with an estimated arrival time of 0940. While en route, Apache 51 made position reports every 15 minutes as required by RLC to the company's communications center. These reports included the remaining miles to the intended destination, which were at 85, 59, and 27 nautical miles from CAM. At 0928, the pilot reported to RLC's communication center on frequency 129.8 that he was 10 miles south of CAM. The pilot then switched to the local area common traffic advisory frequency (CTAF) of 123.05. A representative from RLC stated that 10 miles out from CAM is the last standard call to RLC, and the standard arrival altitude is 500 feet. Approximately 0930, another pilot who was flying in the vicinity reported hearing on local area common traffic advisory frequency, 123.05 mhz, the following: "Mayday, mayday, mayday, Apache (garbled), I'm going down, I'm going down, 10 miles south of Sabine... I mean 10 miles south of Cameron." The commercial pilot tried to confirm Apache 51's location, and heard "10 miles south of Cameron, 10 miles south of Cameron." No further radio transmissions were received from Apache 51, and there were no reported eyewitnesses to the accident. PERSONNEL INFORMATION The 66-year old pilot had been employed by RLC since December 28, 1999, and was assigned to CAM. He began his seven-day work schedule on July 16, 2004, by driving from his home in Nederland, Texas, about one hour away, before reporting for duty at 0545. The pilot departed on the first flight of the day on July 16, 2004, at 0637, and returned to the CAM base at the end of the day at 1805, logging 8.0 hours of flight time. The next morning on July 17, 2004, the pilot reported for duty at 0545, before departing on the first flight of the day. Two co-workers (flight follower and pilot), who also work for RLC and knew the pilot, noted uncharacteristic behavior on the day before and the day of the accident. Both witnesses observed that an otherwise focused, precise, and cheerful pilot exhibited confusion and agitation, which resulted in numerous flight-communication errors that were made by the pilot during the two-day period. The pilot held an airline transport certificate with a rotorcraft helicopter rating. The pilot was issued his most recent first-class medical certificate on December 29, 2003, with the restriction of "must wear lenses that correct for distant vision and possess glasses that correct for near vision." According to company records, the pilot had accumulated 18,056 hours total flight time, all in helicopters, of which 10,530 hours were in the accident make/model helicopter. In the preceding 90 days, the pilot had logged 226 hours of flight time, and in the preceding 30 days, he had logged 85 hours of flight time. On January 26, 2004, in accordance with 14 CFR Part 135 recurrent and proficiency check training requirements, the pilot satisfactorily completed RLC's Bell helicopter 206 series annual recurrent training course and check ride. The pilot had also completed RLC's Bell Helicopter 407 training requirements on April 13, 2004. AIRCRAFT INFORMATION The 1980-model Bell 206L-1, serial number 45392, was powered by a 650-horspower Rolls-Royce Allison 250-C30P turbo shaft engine, serial number CAE 898015, driving a two-bladed main rotor system and a two-bladed tail rotor. There was no flight data recorder or cockpit voice recorder installed on the helicopter, nor was there a requirement for one. The Bell model 206 helicopters are maintained in accordance with Aircraft Type Certificate Data Sheet number H2SW and the appropriate Bell model Maintenance Manual. The Bell model 206 series of RLC's Approved Aircraft Inspection Program (AAIP) requirements (regardless of model) are: 1. 200-hour tail rotor gearbox and transmission oil change. 2. 600-hour hydraulic and facet filter bypass. 3. 7-day airframe inspection. 4. 3-month emergency equipment inspection. 5. 6-month float inspection. 6. 12-month main rotor mast internal inspection. 7. 24-month flight control bolt inspection. In addition, RLC's Bell 206L-1, L-3, and L-4 accomplish the following inspections: 1. Daily preflight inspection. 2. 100-hour airframe inspection. 3. 300-hour airframe inspection. 4. 1200-hour airframe inspection. The AAIP requires that the Allison Model 250-C30 engine be maintained in accordance with Engine Type Certificate Data Sheet number E1GL, and engine life-limited parts be replaced in accordance with Allison Operation and Maintenance Manual 16W2. Engines parts that require overhaul are to be overhauled in accordance with Allison Overhaul Manual 14W3. The original 250-C28 engine was removed from the helicopter and converted to a 250-C30P engine in accordance with Allison Commercial Engine Bulletin (CEB) 72-3120 authorization, and returned to service on April 5, 2004. The conversion was listed under RLC's work order 2369, with engine total time of 2,734.7 hours. The engine was reinstalled on N1078C on May 3, 2004, in accordance with Air Services International, Supplemental Type Certificate (STC) SH296NM. On May 12, 2004, N1078C was released for service after being refurbished (paint, windows, interior, wiring harness, and several avionic and component changes). The 100-hour airframe, 300-hour airframe, and the 1,200-hour airframe inspections were also accomplished. The engine had 2,734.7 hours and the airframe had 22,469.8 hours. On July 4, 2004, the Allison 250C30 150-hour engine inspection was accomplished. The airframe total time was 22,612.5 hours and the engine total time was 2,869.4 hours. On July 11, 2004, the 7-day airframe inspection was accomplished. The airframe total time was 22,641.1 hours. On July 14, 2004, the 100-hour airframe inspection was accomplished. The airframe total time was 22,658.5 hours. On July 15, 2004, the 200-hour tail rotor gearbox and transmission oil change was accomplished. The airframe total time was 22,666.4 hours. RLC's component status report dated July 15, 2004, was reviewed for verification of component serial numbers and times. Bell Helicopter Service Bulletins and Airworthiness Directives were reviewed for compliance, with no noted discrepancies. N1078C's maintenance logbook was reviewed from June 1, 2004 to July 16, 2004, including corrective actions for all discrepancies. No anomalies or unusual events were noted, and no open discrepancies or deferred items were listed in maintenance records at the time of the accident. Maintenance training records for the two maintenance technicians assigned and working at the Cameron onshore base were reviewed, and no discrepancies were noted. A weight and balance form sheet was computed for the NTSB's investigator-in-charge (IIC), with estimated weight for crew, cargo, and fuel for determining center of gravity (CG). The result of the computation was that the aft, forward, and lateral CG ranges were within the gross weight limits. Fuel samples were taken by RLC from WC 544 (last location the helicopter was fueled) at 1119 on July 17, 2004. The fuel sump and filters were checked and found absent of visual debris and fungus. The fuel samples were clear and bright with no anomalies noted. From RLC's maintenance records, N1078C was estimated to have had a total of 22,676.7 hours at the time of the accident, and the engine had accumulated a total of 2,931.30 hours, with 53.9 hours since the last inspection and 196.6 hours since the last overhaul. METEOROLOGICAL INFORMATION The Petroleum Helicopters Inc. (PHI) weather facility at Cameron Heliport (K7LA5), near Cameron, Louisiana, reported at 1012 CDT, wind 250 degrees at 9 knots, visibility 7 statute miles, few clouds at 4,000 feet, few clouds at 12,000 feet, broken clouds at 25,000 feet, temperature 30 degrees Celsius, dew point 23 degrees Celsius, and an barometric pressure of 29.94 inches of Mercury. A pilot for RLC that was in the Cameron area at 0930 reported: "clear skies with unlimited visibility, temperature 80-85 degrees, wind out of the southwest at about 10 knots, and no smoke or haze." A pilot for another company that heard the mayday radio transmission stated that the "weather was very good, with some haze, but good visibility and no rain in the area. The wind was light and variable, and nothing in the area that would give low visibility, lightning, or turbulence." An employee working on platform WC 61, (about five miles west of the wreckage site) saw a line of thunderstorms, oriented east to west, move through the area earlier in the morning. He also reported a brief period of intense rain and recalled seeing a number of waterspouts on the eastern end of the storm. Visible satellite imagery showed a broken line of cumulus and towering cumulus clouds extending from approximately 10-12 nautical miles southeast of Galveston, Texas, east-northeastward to near Grand Chenier, Louisiana. The broken line of clouds was generally stationary, but cloud elements within the line moved east northeastward during the time of the accident. In addition, satellite imagery showed that the line of cumulus was diffused in the area just south of the accident location. The visible satellite imagery (with a nominal resolution of one kilometer) did not indicate any clouds within about 3 nautical miles of the accident site. A cellular cloud mass located about 4-5 nautical miles southwest was the only prominent cloud feature near the accident. Lake Charles (KLCH) Weather Surveillance Radar-1988, Doppler (WSR-88D) reflectivity data for 0924:44 and 0932:30 did not indicate any radar echoes in the vicinity of the accident. The cloud mass shown in the satellite imagery southwest of the accident site was depicted in the reflectivity data as diminishing in intensity during the six minute period. Maximum radar tops were shown as decreasing from about 8,000 feet to about 4,000 feet. A Meteorological Factual Report by a senior meteorologist from the NTSB is included in the docket of this report as supporting documentation. COMMUNICATIONS There are statements from two pilots from different companies that heard the emergency mayday radio transmission. Both of these pilots stated that the pilot from Apache 51 sounded professional and calm. His voice was clear with no background noise, however, there was no reason given by the pilot for the emergency distress call. AERODROME INFORMATION The Gulf of Mexico is divided into block areas (three statute miles long and three statute miles wide), for oil/gas lease identification, and according to information from Helicopter Association International (HAI), there are over 5,500 offshore production platforms along the coastline of several states and into the Gulf. WRECKAGE AND IMPACT INFORMATION The wreckage was located about 12 miles south of Cameron, Louisiana, at latitude 29 degrees 38.015 minutes North, longitude 93 degrees 18.470 minutes West. The main body of the fuselage was recovered approximately 1440 on July 21, 2004. The depth of the water is 30-40 feet in the area. The recovered wreckage was moved onto a boat and transported to shore. The wreckage was then hauled by truck to RLC facilities at Broussard, Louisiana, for examination by the NTSB investigator-in-charge (IIC), with representatives from the Federal Aviation Administration (FAA), RLC, Bell Helicopter, and Rolls-Royce. The helicopter was broken into four main sections: the main cabin section, aft vertical fin and tail rotor gearbox/assembly, the cabin roof with main transmission and rotor assembly to the aft end of the passenger compartment, and tail boom and fuselage aft of the main fuel cell. The front of the cabin section and cockpit interior was mostly intact, with the left windshield, lower cabin chin bubble, and upper green house broken. The left side of the fuselage sustained inward crushing along its entire length. The left front door was distorted. Front and right-side cabin damage was less than the left side. The right front portion of cabin structure, including the windshield, lower cabin chin bubble, and upper green house were relatively intact. The cockpit controls and instruments, including cyclic and anti-torque pedals were intact. Rod end connections for flight controls from the cockpit to the main and tail rotor system were connected. The fuel bladders were intact, and an estimated 63 gallons of fluid (48 gallons of turbine fuel and 15 gallons of sea water) was removed when the fuel bladders were drained. The landing skids remained attached to the fuselage. Both the forward and aft cross tube skid attach brackets on the left skid were fractured, however both remained attached. RLC recovery personnel discharged the float inflation bottle prior to being transported to the RLC facility. The top portion of the central area of the aircraft, comprising the main beam, nodal beam assemblies, transmission and mast, the rotor head, and inboard portions of the main rotor blades were separated as a unit. Another section consisted of the engine, engine deck, lower aft fuselage, most of the tail boom, and tail rotor drive shafting. All of the engine mounts were fractured, but the attaching legs were securely attached to the engine. The engine remained attached by various oil and fuel lines. The lower aft fuselage exhibited upward left to right damage. The tail boom was significantly damaged, including being twisted and bent approximately one foot aft of its attach point. There was longitudinal twisting along its entire length. The tail rotor drive-train remained partially mounted atop the tail boom. The number four tail rotor drive shaft was separated at a point coincident with an upward bend in the tail boom. The number five hangar bearing and associated coupling were separated from the tail boom. The aft section of the number seven and the entire number eight sections of the tail rotor drive shaft, including the spline coupling that drives the 90-degree gearbox, were missing. The aft portion of the tail boom was separated, and consisted of the vertical fin, tail rotor 90-degree gear box, mounting attachment for the gearbox, tail rotor assembly, and cowling. One tail rotor blade was separated approximately two inches outboard of the blade grip. The other tail rotor blade was coned outward. The main transmission remained intact and attached to the upper cabin assembly of the fuselage. The drive shaft was fractured at the aft flex coupling, with circumferential scoring noted on the shaft.. The mast and drive shaft rotated freely when rotated by hand. The roots of both main rotor blades remained attached to the main rotor head. Both blades exhibited downward bending. One blade was fractured approximately 30 inches outboard of the blade retaining bolt, and the fracture surface of the portion remaining attached to the head exhibited a

Probable Cause and Findings

The helicopter's in-flight collision with water for undetermined reasons.

 

Source: NTSB Aviation Accident Database

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