FTW02TA060

The helicopter departed and was in cruise flight at 4,500 feet msl (approximately 500 feet agl) when the pilot heard a "muffled pop." Approximately 2 seconds had passed when the pilot heard a second muffled pop, followed by either the low rotor rpm or engine out warning horn. The pilot then entered an autorotation to a residential street. During the autorotation, the pilot maneuvered the helicopter to avoid a moving ground vehicle. Subsequently, the main rotor blades contacted trees, the helicopter landed hard, and it came to rest upright. The pilot had accumulated 865 hours in helicopters with 4 hours in the make and model of the accident helicopter, at the time of the accident. The engine was examined; its outer casing was intact and there was no evidence of a catastrophic engine failure. A pneumatic check was performed and no leaks were found. The fuel lines were examined and no loose fittings or fuel leaks were found. The engine was removed from the airframe, placed in a test cell, and a test run was performed. The engine operated within the manufacturer's specifications at idle, cruise, takeoff, and maximum power settings. The reason for the loss of engine power was not determined.

On December 27, 2001, at 1305 mountain standard time, a Bell OH-58A helicopter, N76PD, was substantially damaged when it landed hard during a forced landing following a loss of engine power near El Paso, Texas. The helicopter was owned and operated by the El Paso Police Department, El Paso, Texas. The commercial pilot, sole occupant of the helicopter, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the public use flight. The instructional solo flight originated from the El Paso International Airport, El Paso, Texas, at 1300, and was destined for the Dona Ana County Airport, Santa Teresa, New Mexico.

According to the pilot, he departed from the airport and was in cruise flight at 4,500 feet msl (approximately 500 feet agl) when he heard a "muffled pop." Approximately 2 seconds had passed when the pilot heard a second muffled pop, followed by either the low rotor rpm or engine out warning horn. The pilot then decided to execute an autorotation to a residential street. During the autorotation, the pilot maneuvered the helicopter to avoid a moving ground vehicle. Subsequently, the main rotor blades contacted trees, the helicopter landed hard, and it came to rest upright. During the landing, the main rotor blades were damaged and the vertical stabilizer separated from the airframe. The pilot had accumulated a total time of 865 hours in helicopters, of which 4 hours were in the OH-58A.

On January 11, 2002, representatives from Rolls-Royce and the El Paso Police Department examined the helicopter's airframe and the Rolls-Royce T63A-720 turboshaft engine. The engine's outer casing was intact and there was no evidence of a catastrophic engine failure. They performed a pneumatic check and found no leaks. The fuel lines were examined and no loose fittings or fuel leaks were found. The engine was removed from the airframe and sent to Dallas Airmotive, Dallas, Texas.

On January 17, 2002, the engine was test run at Dallas Airmotive, under supervision of the NTSB Investigator-In-Charge. The engine operated within the manufacturer's specifications at idle, cruise, takeoff, and maximum power settings.

A review of the helicopter's maintenance records revealed that, on October 22, 2001, a 1,200 hour airframe inspection and a 300 hour engine inspection were completed. The airframe had accumulated a total of 4,228.2 hours and the engine had accumulated a total of 834.0 hours at that time. At the time of the accident, the airframe and engine had accumulated a total of 4,233.9 hours and 839.7 hours, respectively.