NYC07LA146

While on a 2-mile final approach to a runway, at 700 feet above ground level (agl), the helicopter pilot heard a loud "bang," which was followed by a total loss of engine power. The pilot performed an autorotation to a residential area, and the helicopter sustained substantial damage. The helicopter was manufactured in 1962, and the exact age of the engine could not be determined. The engine was last overhauled in 1990, and had accumulated about 224 hours of operation since that overhaul. Subsequent examination of the engine revealed that the number one connecting rod experienced a total failure, which also damaged the engine case.

On June 20, 2007, at 1848 eastern daylight time, a Bell-Carson 47G-Super C-4 helicopter, N867Z, was substantially damaged during a forced landing to a residence in Wall Township, New Jersey, after experiencing a total loss of engine power while on approach to Monmouth Executive Airport (BLM), Farmingdale, New Jersey. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed for the local flight, and no flight plan had been filed for the personal flight conducted under 14 Code of Federal Regulations Part 91.

The pilot stated that he departed BLM, and flew locally for approximately 1 hour. He was returning to the airport, and on a 2-mile final approach for runway 32. The helicopter was at 700 feet above ground level (agl), and an airspeed of 60 knots, when the pilot heard a "bang." The engine then lost all power, and he performed an autorotation to a residential yard. During the autorotation, the helicopter rolled partially on its right side, and sustained damage to the main rotor blades, fuselage, and tailboom.

Review of Federal Aviation Administration (FAA) records and the aircraft logbooks revealed that the helicopter was manufactured in 1962. The helicopter was equipped with a Franklin model 6V-350-A, 235-horsepower engine. The exact age of the engine could not be determined; however, it was last overhauled in 1990. The pilot reported that at the time of the accident, the engine had accumulated 224.2 total hours of operation since the last overhaul. The helicopter had been operated for 11.8 hours since its most recent annual inspection, which was performed on February 8, 2007.

The pilot subsequently had the helicopter examined at a repair facility, and noted that the number one connecting rod experienced a total failure, which also damaged the engine case. The pilot added that oil was observed throughout the engine.