The upgrade of the Royal Navy Commando Helicopter Force's (CHF's) 25-strong Merlin HC3/3A helicopter fleet to HC4/4A standard has been completed.

Upgrade work was performed on all 25 helicopters - comprising 19 HC3s and six HC3As - extending the Commando Merlin fleet's service life to 2030 and enhancing its ability to support operations carried out by the Royal Marines and other UK military forces. As part of the upgrade a new folding main rotor head and folding tail was fitted to each helicopter, allowing for two Merlins to fit on one of the Queen Elizabeth-class aircraft carriers' onboard lifts when the type is supporting Carrier Strike Group operations around the globe.

An improved defensive aid suite (DAS) with a system that warns against and locates hostile laser-guided weapons has also been integrated onto the Merlin as part of this life extension upgrade. "These upgrades mean that many consider the Merlin HC4/HC4A to be the world's most advanced amphibious battlefield helicopter," Defence Equipment & Support, the procurement arm of the UK Ministry of Defence (MOD) said in a press release.

As a helicopter that is charged with carrying out multiple roles - including search and rescue, counter-narcotics, anti-piracy, maritime security and hurricane relief support operations - this upgrade allows the Merlin HC4/HC4A to embark and operate from both Queen Elizabeth-class aircraft carriers, amphibious assault ships, Duke-class (Type 23) frigates and eventually Daring-class (Type 45) destroyers.

Leonardo Helicopters performed the upgrade under the Merlin Life Sustainment Programme (MLSP) at its facility at Royal Naval Air Station (RNAS) Yeovilton in Somerset. In addition to the Merlin upgrade, two new pilot simulators, a procedures trainer and a rear crew training device - which leverages augmented reality (AR) technology - is now in place at Yeovilton.

Commenting on the Merlin upgrade, Col Mark Johnson (Royal Marines), commanding officer of the CHF, said: “The Merlin [HC4/4A] - colloquially known as the Commando Merlin - is proving to be a game-changing capability upgrade for the CHF. It has already demonstrated itself to be a critical enabler of the Royal Navy’s strategic outputs – contributing to the security of the UK, enabling the Carrier Strike Group to deliver the F-35 from the maritime, and delivering the United Kingdom’s Commando Forces in the littoral."