Royal Navy’s Commando Merlin helicopters achieve Full Operating Capability following major upgrade

The Merlin Life Sustainment Programme (MLSP), managed by Defence Equipment & Support (DE&S), has successfully transitioned the fleet from the AW101 Mk3/Mk3a models to the fully ship-optimised Mk4/Mk4a variants. In total, 19 Mk3 and six Mk3a helicopters have been upgraded, significantly improving the capability of the Commando Helicopter Force (CHF) to support both Royal Marines and wider UK military operations.

This transformation was achieved through a collaboration between DE&S, Leonardo Helicopters UK, and the Royal Navy. The upgrades include a folding main rotor head and tail, allowing two helicopters to fit on a single aircraft lift aboard Royal Navy carriers, as well as an enhanced defensive aid suite to counter laser-guided threats. These modifications make the Merlin Mk4/4a one of the world’s most advanced amphibious battlefield helicopters.

Captain Neil Mathieson RN, Merlin Delivery Team Leader at DE&S, highlighted the significance of the upgrades. “The key difference between the Mk3/Mk3a and the new variant is that the Mk4/Mk4a has been fully ‘ship optimised’ to allow it to embark and more efficiently operate from Royal Navy vessels,” he explained. He added that these improvements ensure the fleet is globally deployable for all maritime operations.

Beyond operational enhancements, the aircraft now share greater commonality with the wider Merlin fleet, benefiting from a modernised cockpit and avionics suite. This alignment with the Merlin Mk2 model extends the service life of the helicopters to 2030, ensuring continued interoperability and maintenance efficiency across platforms.

Clive Scott, Senior Vice President of Leonardo Helicopters UK, praised the role of British engineering in delivering these upgrades. “Our workforce is proud to have delivered these upgrades for the Royal Navy Merlin fleet from our site in Yeovil, the home of British helicopters,” he said. He also noted that the AW101 platform, used by allies such as Japan, Italy, and Poland, continues to set the standard for maritime operations.

An integral part of the upgrade programme is the introduction of cutting-edge synthetic training technology. The new training system at RNAS Yeovilton includes two pilot simulators, a procedures trainer, and an augmented reality-based rear crew training device, providing a step-change in aircrew training capability. This co-located facility allows for more effective mission rehearsal and front-line training.

With FOC now declared, the Commando Merlin is officially cleared to operate from Royal Navy aircraft carriers, amphibious assault ships, Type 23 frigates, and Royal Fleet Auxiliary vessels. It will also integrate into operations from Type 45 destroyers, further expanding the Royal Navy’s air mobility capabilities.

The upgrades enable Merlin helicopters to play a central role in littoral manoeuvre operations, where aircraft are launched from naval vessels to conduct amphibious missions before returning to the ship. This capability enhances the Royal Navy’s ability to conduct rapid-response missions, including search and rescue, counter-narcotics, anti-piracy, and humanitarian relief operations.

The £399 million MLSP contract with Leonardo has not only delivered a world-class capability but has also strengthened UK defence manufacturing. The enhancements provide long-term cost efficiencies in maintenance, training, and logistics, ensuring that the Royal Navy’s Commando Helicopters remain at the forefront of modern amphibious operations.