NTSB Factual Report

HISTORY OF FLIGHT

On May 25, 1998, about 0032 eastern daylight time, a Bell 206L-3 helicopter, N96CW, collided with a high tension static ground wire, and subsequently the ground, during cruise flight, at Indian Trail, North Carolina. The helicopter was operated by U.S. Helicopters, Inc., under the provisions of Title 14 CFR Part 135, and visual flight rules. Night, instrument meteorological conditions prevailed at the accident site. A flight plan was not filed. The commercial pilot and the four passengers were fatally injured, and the helicopter was destroyed. The on-demand, passenger flight originated from a helicopter landing zone at the Charlotte Motor Speedway, Charlotte, North Carolina, at 0010, and was destined for Monroe, North Carolina.

According to US Helicopters, Inc., the pilot was conducting passenger transport from the Charlotte Motor Speedway to various destinations in the Charlotte area. The pilot was on his last trip of the day, and departed the Speedway with four passengers on board destined for the Monroe Airport. Upon de-planing of the passengers at Monroe, he was scheduled to return to US Heliport (NC56).

Prior to departing the Speedway, the pilot informed a co-worker that weather at the time was VFR with 3 miles visibility. The passengers received a pre-flight briefing from the co-worker and the co-worker personally insured that all passengers had their seatbelts properly secured, and that the doors of the helicopter were properly closed. According to the co-worker, the pilot had last reported that he was proceeding east along highway 74, about 0025.

According to witnesses, in the immediate area, the helicopter was observed flying low, in fog, with its lights on. It subsequently collided with a wire about 150 feet above the ground, then came to rest in the median of U.S. Highway 74.

PERSONNEL INFORMATION

The pilot was certificated as a commercial pilot and certified flight instructor with instrument ratings in single engine, multi-engine land and helicopters. The pilot reported having 5000 hours on his last medical examination. The pilot's most recent second class medical was issued on April 13, 1998. The pilot's most recent flight review was dated July 29, 1997, and was given in a Bell 206 Helicopter. Additional pilot information may be obtained in this report on page 2 and 3 under the section titled Owner/Operator and First Pilot Information.

AIRCRAFT INFORMATION

The Bell Long Ranger III, 206L-3, serial number 51286, N96CW, was a single engine, land-based helicopter configured for one pilot and four passengers, and was equipped with a wire protection system. The aircraft's total time was about 1445 hours. On March 6, 1998, the helicopter received an annual/100 hour inspection. Review of the airframe and engine logbooks and maintenance records found no open faults or pre-existing discrepancies.

METEOROLOGICAL INFORMATION

Instrument meteorological conditions prevailed at the accident site. According to witnesses, visibility at the Charlotte Motor Speed around mid-night was about 3 miles. The report from the Monroe ASOS (Automatic Surface Observation System) located on Monroe Airport was 300 feet overcast sky condition, 1.75 miles visibility in mist. Additional meteorological information may be obtained in this report on page 4, under the section titled Weather Information.

WRECKAGE AND IMPACT INFORMATION

The accident site was located on US highway 74 near the community of Indian Trail, North Carolina. Global Positioning System (GPS) Coordinates: N35 degrees, 3'.9" and W080 degrees, 38'.5". The wreckage was located on the north shoulder of the eastbound lane of the divided highway with the nose of the helicopter pointing to the west. The highway was running from northwest to southeast in that area. Approximately 100 feet to the northwest of the main wreckage was a set of 230 kilo-volt power lines, which crossed the highway at a 90-degree angle. The power lines were mounted on steel truss towers and the two static wires were 150 feet above the roadway. The southeast static wire was separated and the ends of the wire extended into the trees southeast of the towers on both sides of the highway. Examination of the ends of the separated static line revealed cup-cone type fractures. There was no damage noted on the northwest static wire or the main conducting wires of the power line system. None of the wires contained marker balls and the wires were depicted on the Charlotte VFR Terminal Area Chart dated January 30, 1997. The surrounding area of the accident site was flat leading up to the power lines on the aircraft's flight path. The trees in the immediate area of the accident site were approximately 75 feet high. They did not obscure the power cables or the towers, which were approximately 75 feet above the trees. Approximately 50 yards from under the power cables to the resting point of the aircraft was littered with aircraft debris ranging from the aft section of the tailboom, with the tail rotor assembly attached, to window Plexiglas and fly-away gear.

Examination of the fuselage found it severely distorted from a heavy ground impact in an 85-degree rolled left attitude, and crushing of the left side of the fuselage structure was evident. The tailboom was not present on the fuselage and overload fracturing of the structure of the aft fuselage was noted at station 121. A portion of the cowling over the engine oil tank and cooler exhibited a diagonal cut on its left side. The helicopter was equipped with a wire strike protection system and the upper and lower cutter assemblies were still mounted to the roof and underside of the nose. No significant damage was seen to the protective coating on the blades of the upper or lower cutter assemblies.

The tailboom was destroyed and the aft portion of the tailboom containing the tailrotor had separated from boom station 148. The horizontal stabilizer was found separated from the tailboom structure. Both end plates on the stabilizer were found separated. One of the end plates exhibited 3 large cuts several inches apart.

The tailrotor 90-degree gearbox and hub and blade assemblies were still mounted on the aft section of the tailboom. The tailrotor was operable with no significant damage noted to the blades. The pitch change mechanism was operable.

The landing gear was heavily damaged during the accident sequence. Both skid tubes were separated from the front and rear crosstubes from overload fracturing at the skidtube/crosstube attachment fitting. The skid tubes and crosstubes were located adjacent to the main fuselage wreckage. Heavy mechanical scrapes and gouges were found on the forward sides of both left and right legs of the forward crosstube. These scrapes and gouges extended from the skid tube attachment fitting upward to just outboard of each belly saddle. No scrape marks were noted on the rear crosstube.

The main rotor hub and mast were still attached to the main transmission in the main wreckage. The mast was bent approximately 10 degrees just below the static stop contact zone. Both main rotor blades were heavily damaged from ground impact and portions of the afterbody were torn away. Portions of the separated main rotor blade afterbody exhibited chordwise mechanical damage. One area of one main rotor blade, which remained attached to the hub, was scorched on the aft edge near the outboard doublers. No evidence of wire contact was seen on either of the main rotor blades. The main rotor pitch links were fractured. The swashplate and collective sleeve were operable. However, the collective lever idler link was fractured. The boost control linkages from the swashplate and collective lever to the hydraulic servo actuators were intact. The servo actuators were intact and all control-input linkage was connected. The hydraulic system components were intact and fluid was present in the reservoir. The linkage from the hydraulic servos to the cyclic and collective were undamaged.

The engine was found mounted in the fuselage. All lines, fittings and linkage were attached. The transmission was free to rotate. The forward end of the main driveshaft had pulled out of the outer coupling from impact; however, the remainder of the driveshaft was not damaged.

MEDICAL AND PATHOLOGICAL INFORMATION

A post mortem examination of the pilot was conducted by the North Carolina Department of Environment, Health, and Natural Resources, Division of Postmortem Medicolegal Examination, Office of the Chief Medical Examiner, Chapel Hill, North Carolina 27599-7580. On May 27, 1998, the FAA Toxicology Research Laboratory conducted a toxicology examination of the pilot. The examination revealed no Carbon Monoxide, Cyanide detected in the blood, and no Ethanol or Drugs detected in the urine.

TESTS AND RESEARCH

On May 25, 1998, the wreckage was recovered and moved to a garage in Marshville, North Carolina, where a detailed examination of the wreckage was performed. Examination of the engine found the engine mounts were bent and broken, and the particle separator and plenum were extensively damaged. The pneumatic tubing was bent, broken and crushed, the fuel pump housing was cracked and the flange and the bleed valve was separated from the scroll. N1 was rotated but was found to be binding at the main and tail rotor driveshaft outputs on the accessory gearbox. When the shafts were removed, N2 rotated free and smooth and was continuous to the output shaft. The scroll was dented and bent on the top, left side. The right side compressor air discharge tube was crushed and bent and the exhaust duct was crushed.

The fuel supply line from the vertical fireshield to the fuel nozzle was filled with fuel, the fuel filter was filled with fuel and the fuel was clear and bright. The engine oil tank was cut open and did not contain any oil. There was, however, oil in various supply lines, as well as spilled oil at the accident site. Both engine chip detectors were clean.

ADDITION INFORMATION

The wreckage was released to the owner US Helicopters, Inc., PO Box 625, Marshville, North Carolina 28103 on May 26, 1998.

NTSB Probable Cause

The pilot's failure to maintain altitude while operating in adverse weather. A contributing factor was the incoming fog and high tension static wire.