SEA97LA118

The pilot reported that he lifted off vertically and turned the helicopter downwind toward the first sling load. When the helicopter attained an altitude of 70 to 80 feet above ground level, the engine experienced a loss of power. The pilot initiated a hovering autorotation and just before touchdown, the left side landing skid collided with a 17 gallon fuel jug. The helicopter began to roll to the right and the right side landing skid collided with the ground and collapsed. The helicopter continued to roll to the right and came to rest on its right side. Post accident investigation of the engine revealed that the pneumatic line at the fuel control of the engine was disconnected. Two days prior to the accident the fuel control had been replaced and the mechanic stated that all of the B-nuts had been properly torqued. The pneumatic line, B-nut and threads, and the mating connection on the fuel control were inspected for damage. There was no evidence of damage found to indicate how the B-nut could have backed off the fuel control connection if it had been properly torqued.

On May 21, 1997, at 1000 Pacific daylight time, a Hughes 369D, N8306F, registered to and operated by Olympic Air Incorporated as a 14 CFR Part 133 external load operation, experienced a loss of engine power during takeoff near Moclips, Washington. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter was substantially damaged when the right side skid collapsed on landing and the helicopter rolled onto its right side. The commercial pilot, the sole occupant, was not injured. The flight had originated from Aberdeen, Washington, approximately 30 minutes prior to the accident.

In a written statement, it was reported that the pilot flew the 20 minute flight to the intended work area and landed to talk to the ground crew. After the brief discussion, the pilot attached the 100-foot long line to the helicopter. The pilot returned to the helicopter and lifted off vertically and turned the helicopter downwind toward the first sling load. The pilot reported that the helicopter attained an altitude of 70 to 80 feet above ground level when the engine experienced a loss of power. The pilot turned the helicopter into the wind and initiated a hovering autorotation. Just prior to touchdown, the left side landing skid collided with a 17 gallon fuel jug. The helicopter began to roll to the right and the right side landing skid struck the ground and collapsed. The helicopter continued to roll to the right and came to rest on its right side.

Post accident inspection of the engine by an inspector from the Federal Aviation Administration (FAA) Flight Standards District Office, Renton, Washington, reported that the pneumatic line at the fuel control of the engine was found disconnected. The inspector reported that the line routes Pc air from the compressor scroll through a tee on the power turbine governor to the Bendix fuel control.

Maintenance records indicate that the fuel control was replaced two days prior to the accident, and flight records indicate that the helicopter accumulated a total flight time of 4.8 hours since the fuel control installation. The mechanic who performed the work stated that the B-nut on the pneumatic line had been properly torqued during the installation of the fuel control.

The FAA inspector reported that the pneumatic line, the flare at the end of the tube, the B-nut and threads, and the threads to the mating connection on the fuel control were inspected for damage. The inspector stated that there was no evidence of damage found to indicate how the B-nut could have backed off of the fuel control if it had been properly torqued.