On May 28, 2006, a Hughes 369HS (registration N9244F) was involved in an aviation accident near Mattituck, NY. Investigators recorded the probable cause as: A loss of engine power due to undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter suffered a total loss of engine power while maneuvering below 100 feet over shore and ocean. The pilot performed an autorotation and activated floats; the helicopter impacted water twice, becoming inverted. Both occupants egressed and were rescued.
Incident Overview
During aggressive maneuvering over the shore and ocean, at an altitude below 100 feet above ground level, the helicopter experienced a total loss of engine power. The pilot initiated an autorotation and deployed the float system. The helicopter struck the water in a level attitude with sufficient forward speed to submerge and then rebound 15 to 18 feet into the air. A second impact occurred, this time with the helicopter inverted.
Occupant Egress and Rescue
Both occupants successfully egressed from the submerged helicopter and were rescued shortly after reaching the surface.
Postaccident Examination
A postaccident examination revealed that the main rotor blades had damage consistent with a loss of power. However, examination of the engine and powertrain systems was inconclusive as to the cause of the power loss.