Exclusive inside look at the Royal Navy’s upgraded Merlin helicopter

Henry Jones spent a day getting to know the new Merlin Mk4 with 845 Naval Air Squadron at RNAS Yeovilton.

Returning to RNAS Yeovilton after several hours in the air, one of the crew smiles and jokes “lots of aircraft out today – Russia will be watching”. Fair enough; Yeovilton is home to the world’s most advanced amphibious battlefield helicopter, the newly upgraded Merlin Mk4.

The £388 million upgrade has transformed the capability of the aircraft. The Merlin now has folding rotors and a folding tail, a flare system to evade heating seeking missiles, and a touch screen cockpit suite. Roughly 95% of the internal wiring is also brand new.

The new folding rotors and tail mean four Merlins can fit in the same hanger space as one Chinook. Two Merlin can also fit on one of HMS Queen Elizabeth’s aircraft lifts.

A Chinook helicopter and four Merlin helicopters in the hangar of HMS Queen Elizabeth, showing the different in space taken up by each type.

The Mk4 has an improved defensive aids suite which, for the first time, includes a chaff dispenser. The aircraft also has 6 chaff bins that can counter and confuse radar guided missiles. The Merlin’s laser turret counters heat seeking missiles.

However the most impressive aspect of the Merlin’s new defensive suite is the ‘Laser Warning System’. This alerts the crew if laser guided weapons are targeting the aircraft and can also be used to locate the suspect weapon.

When the crews are training, they can program foreign weapons into the system to simulate operating in a contested environment. Notably, this allows them to train against Russian used missiles.

These counter measures are part of the Merlin’s LAIRCM or ‘Large Aircraft Infra Red Counter Measures’ system.

One of the crew told me that the defensive systems make it “one of if not the most well protected helicopters on the planet”.

The aircraft also has 5 mounts on the fuselage for General Purpose Machine Guns (GPMG). The crew boast that while the Chinook uses miniguns, these can’t be detached from the aircraft and brought with you in the event of a crash landing. A GPMG can be.

The new Merlin also has an upgraded cockpit suite, with touchscreen displays and the ability to fly instrument patterns. These screens will also be used to control the cameras that are going to be fitted to the aircraft later this year. This gives the Merlin a flexible Intelligence, Surveillance, Target Acquisition and Reconnaissance (ISTAR) capability.

Another boast for the Merlin is its range: up to to 5 hours on its internal fuel tanks is huge for a helicopter. This range could be further boosted by air-to-air refuelling.

Officially, the Mk4 can refuel while airborne: it has all the necessary internal piping. The Royal Navy however does not currently fund this as a capability, and would need significant investment to make it a reality. Air-to-air refuelling remains merely an aspiration for the Merlin.


I’ve been lucky enough to see a wide range of armed forces equipment in action. None of it left me more impressed than the Merlin Mk4 did.

The U.S. has a different type of helicopter for each capability it requires. The UK’s way of thinking is different; have a few types of helicopters that can fulfil all the capabilities that are required. The Merlin is remarkably versatile. It is equally at home in the UK as it is in Nevada, or Norway, or in a jungle, or operating from HMS Queen Elizabeth.

We left RNAS Yeovilton a little behind schedule. That time was made up by simply flying faster. The aircraft was comfortable and remarkably stable. I was told that unlike the Chinook, when soldiers are picked up in a Merlin after a long exercise they strap in and fall straight asleep.

The Merlin is also remarkably reliable; during last year’s Exercise Joint Warrior the aircraft didn’t miss a single one of its taskings due to serviceability issues. That’s unheard of for helicopters.

All in all, a deeply impressive piece of equipment. Thank you to 845 Naval Air Squadron for hosting me.

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