New York, NY, USA
N78TD
Bell 206L
The helicopter landed at the heliport with approximately 220 lbs. of fuel on board. At that time, the helicopter was oriented to north, with a light westerly wind. The helicopter was on the ground for 2 to 3 minutes while ground personnel boarded passengers for a sightseeing flight. The helicopter lifted up to a hover and initially turned left 90 degrees toward west, but the wind was from the northeast at approximately 5 knots. When the pilot realized the wind was from the other direction, he then turned right about 270 degrees. The pilot initiated a southeasterly takeoff run, oriented about a 160-degree heading. During the approximate 275-foot takeoff run, the skids contacted the ground at least once as the pilot attempted to increase forward speed. The pilot felt like the helicopter did not have full power during the takeoff run; however, the pilot and passengers did not recall any cockpit warnings or anomalies. The helicopter did not gain altitude as it neared the end of the heliport, and the tailrotor struck the edge of the pier as the helicopter descended towards the water. The helicopter subsequently impacted the water and rolled inverted. Examination of the helicopter did not reveal any pre-impact mechanical malfunctions. The pilot did not ask passengers their weight, and did not have a scale at the heliport. Rather, he estimated the weight and balance. For the accident flight, he estimated 150 lbs. per person, as there were three male passengers, and three female passengers. However, the average weight of the passengers was approximately 188 lbs. The weight of the occupants and the weight of the fuel revealed that the helicopter was about 222 lbs. overweight at the time of the accident; not including the weight of clothing, personal effects, and baggage. In addition to being over the maximum gross weight, the helicopter was at or beyond its performance limits for the environmental conditions, and the takeoff was attempted with a light left crosswind or quartering tailwind.
HISTORY OF FLIGHT On June 14, 2005, at 1338 eastern daylight time, a Bell 206L helicopter, N78TD, was substantially damaged when it impacted the East River during takeoff from the Port Authority Downtown Manhattan/Wall Street Heliport (JRB), New York, New York. The certificated commercial pilot and five passengers sustained minor injuries, while one passenger was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local commercial sightseeing flight conducted under 14 CFR Part 91. According to his written statement and telephone interview, the pilot reported that the helicopter was based at Teterboro Airport (TEB), Teterboro, New Jersey. The helicopter was fueled the previous night, and had approximately 220 pounds of fuel on board at the time of the accident. After repositioning to JRB, the helicopter was on the ground for 2 to 3 minutes, while another employee boarded the passengers. The helicopter was oriented about a northerly heading at JRB, and although heliport operations reported the wind as calm, the pilot recalled the wind from the west (left) when he landed. Upon departure, the pilot initially entered a hover and turned left, but then realized the wind was from the northeast from approximately 060 degrees at 5 knots. The pilot then turned right and began a southeasterly takeoff run, about a 160-degree heading. During the approximate 275-foot takeoff run, the skids may have contacted the heliport once. The pilot felt like the helicopter did not have full power during the takeoff run. However, he verified the torque at 96 percent and the temperature was "OK." Additionally, the pilot stated he did not hear or see any cockpit warnings. He then thought that the helicopter may need more forward speed, and he attempted to increase the speed. The helicopter did not gain altitude as it neared the end of the heliport, so the pilot executed a turn to the right in an attempt to clear the tailrotor from the pier, but the tailrotor struck the edge of the pier as the helicopter descended. The helicopter then impacted the water, the pilot deployed the floats, and the helicopter rolled quickly inverted. When asked about the lack of engine power, the pilot stated that normal full power for the helicopter was 100 percent torque, but the manufacturer allowed 105 percent torque for 5 seconds. The pilot normally obtained 90 to 98 percent torque during takeoffs, depending on temperature and wind. Although there were no cockpit warnings, the pilot thought that the rotor rpm might have been low as the helicopter descended into the water. When asked about the reason for the lack of engine power, the pilot added that sometimes dirt or dust could lodge in the fuel system (N1 governor) and then dislodge during the impact sequence. When asked if the helicopter was overweight, the pilot stated no, because he was able to hover with an indicated turbine outlet temperature TOT of 720 degrees C, and 92 percent torque. Review of a surveillance video, provided by the New York City Department of Transportation, revealed that the helicopter lifted up to a hover, and performed an approximate 90-degree left turn. The helicopter then performed an approximate 270-degree right turn, and began a southeasterly takeoff run over the heliport. Upon reaching the end of the heliport, the helicopter descended into the water and rolled inverted. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with ratings for airplane single engine land, airplane multiengine land, instrument airplane, and helicopter. The pilot's most recent Federal Aviation Administration (FAA) first class medical certificate was issued on November 1, 2004. The pilot reported a total flight experience of 6,520 hours; of which, 5,800 hours were in helicopters. In addition, the pilot flew 191 hours during the 90-day period prior to the accident, all of which was in helicopters. AIRCRAFT INFORMATION The helicopter was manufactured in 1977, and equipped with a Rolls-Royce (Allison) model 250-C20R/2, 450-horsepower, turboshaft engine. The helicopter was maintained under a Manufacturer's Inspection Program. The most recent 100-hour inspection was performed on June 2, 2005. At that time, the helicopter had accumulated at total of approximately 17,140 hours. The helicopter accumulated about 15 additional hours from the time of the inspection, until the time of the accident. METEOROLOGICAL INFORMATION A weather recording station (KNYC) was located in Central Park, New York, about 5 miles north of the accident site. The recorded weather at 1351 was: wind from 290 degrees, varying from 140 degrees to 040 degrees, at 7 knots; visibility 10 miles; ceiling broken at 5,500 feet; temperature 88 degrees F; dew point 66 degrees F; altimeter 29.64 inches Hg. WRECKAGE AND IMPACT INFORMATION Examination of the wreckage revealed that the majority of the helicopter remained intact, and the emergency skid floats had inflated. The front windscreens had separated, and the upper portion of the fuselage exhibited slight bending to the right. The rotor mast also exhibited bending, and a witness mark was observed on the mast, consistent with rotor hub contact. The outboard sections of both main rotor blades had separated approximately 3 feet from the blade roots. The remaining portions of the inboard rotor blades were curled upward near the separation point. In addition, the tailboom partially separated about 2 feet forward of the 90-degree gearbox. The partial separation was consistent with impact damage. One tail rotor blade was separated approximately 6 inches from the blade root, consistent with impact damage. The other tail rotor blade remained intact, and was bent outward. The tail rotor pitch change linkage remained intact. Review of the cockpit revealed that the throttle was in the full throttle position. Throttle control continuity was confirmed from the throttle to the fuel control unit. Flight control continuity was confirmed from the collective and cyclic to the point of control linkage separation at the swashplate. The linkage separation was consistent with impact damage. Flight control continuity was confirmed from the pedals to the tailrotor pitch change linkage. Continuity was also confirmed from the tail rotor through the 90-degree gearbox, and rotational scoring was noted on the short shaft. In addition, continuity was confirmed from the main rotor, through the transmission and engine, to the point of separation at the tailrotor. Although the pilot reported 220 lbs. of fuel onboard at the time of the accident, the director of operations for the operator estimated about 275 lbs. of fuel. Fuel was observed in the fuel lines leading to the engine, and the airframe fuel filter. Approximately 28 ounces of fuel was recovered from the airframe fuel filter. The fuel was bright, clear, and yellow in color. Some sediment was noted at the bottom of the sample container. TESTS AND RESEARCH Engine On September 8, 2005, the engine was disassembled and inspected at the manufacturer's facility, under the supervision of a Safety Board investigator. An air system leak test was performed using 50 psi of air pressure. The test did not reveal any leaks with the air system. The front compressor support was not received from the recovery facility. The starter pad, freewheeling unit, tachometer pad, and exciter were among the airframe components removed for the inspection. Approximately 1/2-ounce of fuel was recovered from the fuel line that connected the fuel control unit to the fuel nozzle. The fuel was consistent in odor and color to Jet A aviation fuel. The fuel was clear, bright, with no contamination observed in the sample. Approximately 2 ounces of fuel was recovered from the engine driven fuel pump. The fuel was consistent in odor and color to Jet A aviation fuel. The fuel was clear, bright, with no contamination observed in the sample. The engine driven fuel pump fuel filter was intact, clean, and no debris was observed. The drive shaft to the engine driven fuel pump was intact. The fuel nozzle was disassembled and inspected. The fuel nozzle filter was intact, clean, and no debris was observed. The power turbine governor, and the fuel control unit were removed. They were observed to be intact, with no discrepancies noted. In addition, the oil filter was intact, oil was present, and no metallic debris was observed on the oil screen. Also, no metallic debris was observed on the upper or lower chip detectors. Examination of the gas producer turbine and power turbine did not reveal any discrepancies. The turbine wheels and vanes were intact, and no damage was observed. The coupling adapter was also intact. The compressor blades were intact and no damage was observed to the blades or the shroud. ADDITIONAL INFORMATION Survival Factors Several of the passengers reported that they viewed a safety video, and were issued personal flotation devices prior to boarding the helicopter. The video provided information on seatbelts, exits, and use of personal flotation devices. The passengers added that the video did not include information on ditching procedures. Review of 14 CFR Part 91 revealed that there was no requirement for the operator to brief the passengers on ditching procedures. None of the passengers recalled any cockpit warning signals prior to impact. A representative from the helicopter manufacturer stated that the floats attached to the skids were supposed to be completely deployed by the pilot before impacting the water. The floats were designed to keep the helicopter from sinking, but could not prevent rollover if deployed in the water. Weight and Balance When asked about the helicopter's weight and balance for the accident flight, the pilot stated that he did not ask passengers their weight, and did not have a scale at the heliport. Rather, he estimated the weight and balance. For the accident flight, he estimated 150 lbs. per person, as there were three male passengers, and three female passengers. When asked if the helicopter was overweight, the pilot stated "no," he was able to hover with 92 percent torque and "720" indicated on the temperature. After the accident, an FAA inspector questioned the passengers about their weights. The passengers reported their weights as 132 lbs., 176 lbs., 187 lbs., 207 lbs., 210 lbs., and 213 lbs. In addition, the pilot weighed approximately 190 lbs. Although the pilot estimated 150 lbs. per passenger, the average weight of the passengers was approximately 188 lbs. The basic empty weight of the helicopter was 2,687.40 lbs. The maximum gross weight of the helicopter was 4,000 lbs., which yielded a useful load of 1312.60 lbs. The weight of the fuel was 220 lbs., as reported by the pilot. The total weight of the occupants was approximately 1,315 lbs. Those weights revealed that the helicopter was about 222 lbs. overweight at the time of the accident; not including the weight of clothing, personal effects, and baggage. Performance Review of a flight manual for the make and model helicopter revealed that the maximum takeoff (5 minute limit) TOT was 810 degrees C. Review of the Power Check Chart, contained in the flight manual, revealed that at 88 degrees F, at sea level, with a TOT of 810 degrees C, the available torque was approximately 92 percent. Review of the Hovering Ceiling In Ground Effect Maximum Continuous Power chart, contained in the flight manual, reveled that at 88 degrees F, at sea level, the maximum hover weight of the helicopter was approximately 3,800 lbs. Review of the Hovering Ceiling In Ground Effect Takeoff Power chart, contained in the flight manual, reveled that at 88 degrees F, at sea level, the helicopter could hover at 4,000 lbs; however, the chart did not provide data beyond the helicopter's maximum gross takeoff weight. Review of FAA-H-8083-21, "Rotorcraft Flying Handbook," revealed: "Performance... Temperature Temperature changes have a large affect on density altitude. As warm air expands, the air molecules move further apart, creating less dense air...High temperatures cause even low elevations to have high density altitudes... Weight As weight increases, the power required to produce the lift need to compensate for the added weight must also increase. Most performance charts include weight as one of the variables. By reducing the weight of the helicopter, you may find that you are able to safely takeoff or land at a location that otherwise would be impossible... Winds... Takeoff and climb performance is greatly affected by wind. When taking off into a headwind, effective translational lift is achieved earlier, resulting in more lift and a steeper climb angle. When taking off with a tailwind, more distance is required to accelerate through translational lift." On the National Transportation Safety Board Pilot/Operator Aircraft Accident Report form, under "Mechanical Malfunction Failure," the pilot checked "No." Wreckage Release The wreckage was released to a representative of the owner's insurance company on June 16, 2005.
The pilot's inadequate preflight planning, which resulted in an attempted takeoff with an overweight helicopter, and subsequent impact with a pier and water. Factors were a high ambient temperature and unfavorable winds.
Source: NTSB Aviation Accident Database
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