Yauco, PR, USA
N6SR
Bell 47G-4A
While enroute to his intended destination, the pilot noticed a reduction in engine power and engine oil pressure and elected to make a precautionary landing to investigate. The pilot selected a parking lot with an approximate 25-degree upslope for the landing area. Approximately five seconds after the initial touchdown in the parking lot, the helicopter started to slide rearward and veered to the right colliding with a parked vehicle. The helicopter came to rest on its side. The helicopter and two parked vehicles burst into flames. The examination of the engine assembly and airframe remains revealed no evidence of pre-impact component failure or system malfunction. Weather conditions were favorable for the formation of carburetor ice. The pilot did not report using carburetor heat at any point during the flight. Review of information on file with the Federal Aviation Administration, revealed the pilot was issued a private pilot certificate with ratings for airplane single engine land and airplane multi-engine land. The pilot's logbook showed that he had accumulated 2,289 hours total flight time with 295 hours of flight time in the accident aircraft make and model. The pilot did not hold a helicopter pilot's rating.
HISTORY OF FLIGHT On May 25, 2002, at 1240 eastern standard time, a Bell 47G-4A helicopter, N6SR, registered to and operated by a private owner, collided with two parked automobiles and burst into flames as the pilot attempted a precautionary landing in Yauco, Puerto Rico. The personal flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The helicopter was destroyed. The right-seated owner/passenger was fatally injured, the center-seated passenger received serious injuries, and the private pilot received minor injuries. The flight departed Isabella, Puerto Rico at 1100. While enroute to his intended destination, the pilot noticed a reduction in engine power and engine oil pressure, and elected to make a precautionary landing to investigate. The pilot selected a parking lot with an approximate 25-degree upslope for the landing area. Approximately five seconds after the initial touchdown in the parking lot, the helicopter started to slide rearward, veered to the right, and collided with a parked vehicle. The helicopter came to rest on the left side. The helicopter and two parked vehicles burst into flames. PERSONNEL INFORMATION Review of information of file with the Federal Aviation Administration (FAA) Airman's Certification Division, Oklahoma City, Oklahoma, revealed the pilot was issued a private pilot certificate on September 20, 1991, with ratings for airplane single engine land and airplane multi-engine land. Review of records on file with FAA Aero medical Records, Oklahoma City, Oklahoma, revealed that the pilot held a third-class medical certificate, with limitations, issued on April 1, 2002. The pilot's logbook showed that he had accumulated 2,289 hours total flight time with 295 hours of flight time in the accident aircraft make and model. The pilot did not hold a helicopter pilot's rating. AIRCRAFT INFORMATION Review of maintenance records revealed the last recorded annual inspection was conducted on September 27, 2001, at which time the Hobbs meter showed 2380.5 hours, and the total airframe time was 1,6367.1 hours. The most current inspection on the helicopter was on January 29, 2002 and the Hobbs meter showed 2405.5 hours of flight time. The engine logbooks showed that the engine was overhauled on March 30, 2001, by High Performance Accessory Service, but was not installed in the helicopter until September 22, 2001. The engine had accumulated 401 hours since the last overhaul. METEOROLGICAL INFORMATION The nearest weather reporting facility at the time of the accident was Mercedita Airport in the city of Ponce. The 1149 surface weather observation was: 2,500 scattered, visibility 12 miles, temperature 87 degrees Fahrenheit, dew point temperature 73 degrees Fahrenheit, wind 140 degrees at 10 knots, and altimeter 30.00. Weather conditions were favorable for the formation of carburetor ice. The pilot did not report using carburetor heat at any point during the flight. WRECKAGE AND IMPACT INFORMATION Examination of the accident site showed that wreckage debris was scattered over an area approximately 100 feet long and 40 feet wide. The examination also revealed that the initial touchdown point was in a confined area, a restaurant parking lot, on a steep upslope of approximately 25 degrees. Two parked automobiles were in the vicinity of the accident site and were destroyed by the fire. The cabin area sustained extensive fire damage. All communication and navigational aids were destroyed by fire. The flight instruments and controls, and all electrical switches were also destroyed by fire. The throttle quadrant was located 15 feet forward of the tail rotor assembly. The throttle cable was still attached to the throttle lever, and the mixture cable was missing. Fire damage was observed at the mixture cable attach point. The anti-torque pedals were missing and the cyclic stick was detached and fire damaged. The fuselage sustained extensive fire damage. One main rotor blade struck a parked car and separated 36 inches from the blade grip. It was bent aft from mid-span to tip. The other main rotor blade remained on the rotor hub and sustained extensive fire damage. The entire tail boom assembly was deformed and fire damaged. Tail rotor drive pitch control cables and horizontal stabilizer cables were attached at respective attach points and were the entire length of the tail boom structure. The tail rotor pitch change linkage was functional. Tail rotor blades were sheared approximately 6 inches and 18 inches from the blade grips. Tail rotor area appeared normal with the tail rotor gearbox assembly attached. Tail skid fractures were present at the aft attach point. Engine accessories were melted and separated from the engine case. The engine could not be rotated more than approximately 1/2 inch due to fire damage. Valve train continuity could not be established due to severe fire damage. The number 1 cylinder head was melted and separated from the cylinder barrel, and the number 1 piston was observed to be intact with heat damage noted. Cylinders number 2, 3, 4, and 5 were internally examined and all pistons and valves were observed intact. The number 6 cylinder was removed and it was observed that the valves and piston were intact. The spark plugs used were not recommended nor approved by the engine manufacturer. The dual magneto and the ignition lead assembly sustained extensive fire damage. The carburetor was fire damaged and the butterfly valve was the only internal component visible. The oil pressure screen was removed and observed to have light fire debris. The oil suction screen was found at the wreckage site and was observed to contain light fire debris. Push rods, and valve springs were also found at the wreckage site, but due to their scattered placement and severe fire damage, it was undetermined which location in relation to the engine they were separated from. The examination of the engine remains revealed no evidence of pre-impact failure or malfunction. ADDITIONAL INFORMATION After the accident, the local police department took custody of the wreckage and relocated it to a nearby police heliport in Ponce, Puerto Rico for the investigation
The pilot's failure to apply carburetor heat that resulted in a partial loss of engine power and the subsequent collision with an object during the forced landing. A factor was weather conditions favorable for the formation of carburetor ice.
Source: NTSB Aviation Accident Database
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