The US National Transportation Safety Board (NTSB) has published its final report into the loss of a Windward Aviation Hughes 360 (N58251) in October of 2020. The Helicopter was carrying out long line operations for Hawai’i Electric and was in a high hover picking up a load when the pilot detected a loss of rotor RPM together with an engine fail annunciation. He released the load and bottomed the collective in an attempt to maintain rotor speed however the RPM continued to decay, and the aircraft impacted the heavily wooded terrain. After impact the engine continued to run, and the pilot completed an emergency shut down. The aircraft was a total loss but happily the pilot escaped with minor injuries. The NTSB found that the partial failure of the Rolls Royce 250-C20B was caused by damage to the start fuel pump. The flapper valve was wedged against the sidewall of the bypass inlet, obstructing about 50% of the discharge port. The pin was in the fuel line between the start fuel pump and the engine-driven fuel pump. The pin found in the fuel line and obstruction from the flapper valve located in the start fuel pump likely induced restricted fuel flow from the engine-driven fuel pump to the engine, which resulted in a partial loss of engine power.
