On May 21, 1997, a Hughes 369D (registration N8306F) was involved in an aviation accident near Moclips, WA. Investigators recorded the probable cause as: Inadequate installation of the fuel control by company maintenance personnel and a loose nut on a line. A disconnected Pc line was a factor. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a vertical takeoff for sling load operations, a helicopter experienced an engine power loss at 70-80 feet. The pilot's autorotation landing was complicated when the left skid struck a 17-gallon fuel jug, causing a rollover.
Accident Sequence
The pilot reported lifting off vertically and turning the helicopter downwind toward the first sling load. As the helicopter reached an altitude of 70 to 80 feet above ground level, the engine lost power. The pilot immediately initiated a hovering autorotation. Just before touchdown, the left side landing skid collided with a 17-gallon fuel jug. The impact caused the helicopter to roll to the right, and the right side landing skid struck the ground and collapsed. The helicopter continued rolling until it came to rest on its right side.
Post-Accident Investigation
A post-accident examination of the engine revealed that the pneumatic line at the fuel control unit was disconnected. The fuel control had been replaced two days prior to the accident. The mechanic who performed the replacement stated that all B-nuts had been properly torqued. Investigators inspected the pneumatic line, its B-nut and threads, and the mating connection on the fuel control for damage. No evidence of damage was found that would indicate how the B-nut could have backed off the fuel control connection if it had been properly torqued.