Royal Navy inquiry finds engine fault caused fatal Merlin ditching

A Service Inquiry has concluded that a fatal Merlin helicopter ditching in the English Channel in September 2024 was caused by an engine fault and an incorrect diagnosis of the emergency by the crew.

The incident occurred on 4 September 2024 while the aircraft was operating with HMS Queen Elizabeth. The investigation found that a split diaphragm in the fuel system of the number two engine caused a runaway, where the engine rapidly increased speed and produced over 130 per cent torque. The crew's attempt to manage the situation led to the inappropriate diagnosis of the emergency, as they moved the switches of two serviceable engines to the OFF position, leaving the runaway engine to maintain control.

The accident resulted in the death of the Handling Pilot, while the Aircraft Commander and Aircrewman successfully escaped the aircraft.