Report finds mistaken engine shutdown caused fatal Royal Navy Merlin ditching

A Royal Navy pilot was killed on 4 September 2024 when a Leonardo AW101 Merlin HC4 was ditched in the sea off the south coast of England. Military accident investigators have concluded that the commander shut down two engines by mistake.

The findings come in a heavily redacted report from the Defence Safety Authority. Lieutenant Rhodri Leyshon was at the controls from the right-hand seat when the aircraft struck the water at a high rate of descent and inverted. He is believed to have died in the cockpit.

The other two crew members got out safely. Lt Leyshon's body was found near the wreckage and recovered 115 minutes after impact.

Lt Leyshon and two other Royal Navy personnel, a second pilot and a rear crewman, neither named in the report, were flying deck landing training from the carrier HMS Queen Elizabeth that day. The crew, from 846 Naval Air Squadron of the Commando Helicopter Force, had flown from RNAS Yeovilton, departing at 17:02, and completed eight deck landings before a meal break.

The helicopter, built in 2001 and carrying the military registration ZJ135, left Queen Elizabeth at 20:35 for night landings using night-vision goggles. About 11 minutes later, roughly 0.25nm from the carrier and travelling at 65kt at 125ft above sea level, a serious fault developed in the number two Safran Helicopter Engines RTM322 powerplant. A rubber diaphragm in the high-pressure fuel metering unit had split.

Examination after the accident found a 5mm-long split in the diaphragm.