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.

Image copyright UK Defence Journal.

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.

A Merlin MK4 on HMS Queen Elizabeth.

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.

Image copyright UK Defence Journal.

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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Alex T



We need more of these excellent machines.


Yes instead of more foreign made Chinook’s

Daniele Mandelli

For ASW yes.

For lift then I’d buy more Chinooks!


I wouldn’t,its cheaper for Merlines and more flexible and we pay British workers not Trump land.
The new Chinooks are special forces optimised and the quieter smaller Merlin that can fly from anywhere and fold down for storage is beter.


Chinooks are the best for hvy lifting and hot and high terrain. That’s just a fact. That’s why the Brits and just about every other Western ally uses them. Would be foolish to replace them in that role with Merlins. Hence the Brits have both airframes.

Btw, America has never been defined by a President. It is a country that has protected freedom all over the world no matter who’s in the Oval Office. Is it a perfect country? No, far from it but without America and it’s people the world would be a very different place today.


I agree with dan. The Merlin is great at what it was designed for and we need more of them . However the Chinook is also an amazing machine and gives our armed forces capabilities that the Merlin can not. Our armed forces should have the best equipment we can get hold of. If that equipment can be reasonably made in the UK then that is what we should go for but if not then we should not spite ourselves and have less suitable equipment.

Trevor Holcroft

I agree with Dan. Talking about Trupmland is daft. America is our ally and it’s equally daft to try to pretend that we can afford to design and build our own Chinook type plane.
Indeed I would say that we too should have a leader that puts UK first… followed (along side?) by our allies.

Daniele Mandelli

This is the CHF variant, ex RAF aircraft.

How does the HM2 ASW variant differ?

Cam Hunter

Did the RAF get more chinooks or anything to make up for losing the Merlins?

Daniele Mandelli

Yes 14. Was to be 22.

Not the recently announced Chinook order this was back in 2009 when Cottesmore was closed as an RAF station and 2 Harrier squadrons were cut.

Cam Hunter

We’ve lost so many dam RAF bases! And there even more historic bases closing soon!!. And Only having 1 in Scotland sucks!, I was looking at google earth and right across the moray Firth coast there’s dozens of old RAF bases on the coast they are everywhere. Right now as I’m writing typhoons are screaming over head with full afterburners heading west from Lossiemouth, so atleast we still got Lossiemouth and it’s only getting bigger. But RAF Kinloss should have been the p8s dedicated European base….

Daniele Mandelli

Agree Cam.

At least many of the RAF Stations are retained on the MoD estate should they be needed again.
Many become army barracks like Leuchars.

One that was not retained was Coltishall, as I understand the infrastructure was naff.

Lyneham, Brawdy, Wattisham, Leuchars, Kinloss, Chivenor, Wyton, Honington as examples all re used.

Agree Kinloss should be the P8 location.


Yes many have been retained in various ways, mostly as Army Barracks but some as MOD establishments, a bit of future proofing I believe from the RAF there. There has been too much cuts for money saving all at the expense of strategy(e.g. all eggs in one basket etc) and it must affect the RAFs ability to have options instead of grouping every aircraft in a couple of bases. I heard somewhere that leuchers is gonna reopen, I believe its gonna take back QRA for a while at least, I could be wrong. Look at Brize Norton, it is massive,… Read more »


A question just popped into my head which maybe someone can answer, where do the military go for medical care since ALL military hospitals have been closed from Haslar to Stonehouse to Uxbridge to Nocton Hall to whatever Army hospitals there were?
That has to be such a massive loss in capability to be able to deal with your own casualties in their own facilities instead of relying on presumable NHS hospitals! The money savings cannot possibly justify that!

Daniele Mandelli


QE Hospital Birmingham has a military wing, and there are several MoD hospital units at NHS hospitals where DMS staff and QARANC nurses work.

Daniele Mandelli

I would also add that seeing the tech advances in civilian hospital surgery that is indeed the best place for our wounded and also our military medical staff to get best practice with the professionals of the NHS.

If privacy is needed the military have their own private wards.

The closure of the hospitals is one cut I am not concerned with.

Rehabilitation centres like Headley Court are another matter and I hear another site is in the offering once Headley closes.

Trevor Holcroft

Let’s be realistic. This is nor WW2 when we had thousands of planes and 1000 bomber raids.

Trevor Holcroft

Re Hospitals… I seem to remember that Belfast Hospital developed leading expertise with gunshot wounds and probably blast wounds as well.


It does not have a ramp at the back and has facilities for launching sonar buoys a dipping sonar and a large radar under its nose.


I am pretty sure the RAF Merlins had a rear ramp.

Daniele Mandelli

They do. I think GWM meant the FAA ASW HM1 / HM2 variants have no ramp?


I am sure the naval versions also have ramps… Although maybe I have only seen the ex RAF ones…

Daniele Mandelli

Sorry, my question was badly worded. I know systems wise differ for the ASW variant, I meant concerning the mods to the HC, folding rotors and tails and the like. I assume the original HM1’s all had that as standard.


You are correct. After double checking the Navy versions did already appear to have folding tails and blades.

Daniele Mandelli

Thank you Lee.
Whatever the mods of either the HC2 or HM2 more would be nice.


I don’t think there are any structural differences between the navy and Raf merlins. As far as I know the differences were in the installed systems. I think they had different radars and the navy ones were able to fire torpedoes. I think the RAF ones had a larger fuel load. Basically nothing that could not be replaced in a refit.


Nice article Henry. Thanks.

Nick C

Lee, the only structural difference between the variants is the ramp on the junglie, the ASW mk 2 doesn’t have it. Otherwise the main parts such as the engines and drivetrain are all very similar if not identical, which helps with spares and maintenance. The differences are all in the systems for the very different jobs they can perform. I take issue with Daniele’s point about lift. On land yes, Chinooks can heft a lot. But the picture of the hangar gives it away, four Merlins for one Chinook. And there is a lot of space between the aircraft in… Read more »

Captain P Wash

Punched well above our Weight Nick C.

Daniele Mandelli

Nope, fair comment Nick concerning Chinook fitting inside.


That is the real downside to the Chinook you cannot quickly fold the blades. The actual fuselage is nearly the same length as a Merlin, but it is at least half as wide again for the skinny tank versions. Folding the blades can be done, but it is labour intensive as components needs to be disconnected and you must leave either one blade pointing aft or forward beyond the fuselage. From past experience the Chinook has a much better availability than the Merlin (Jungly version) as it could be repaired/patched up quicker. A good example is check out pictures of… Read more »


Just out of interest, is there anyone currently in the navy on here who actually has some insight into just how many Merlins and Wildcats the navy is short of if all our assets had to go onto a war footing? From my fairly limited ignorant observations, i keep wondering why an appropriate helicopter (s) isn’t/aren’t assigned to each platform full time. They are the vital to a ships ability to see and to fight, and I can’t see that there are enough for all active ships to have one each when sailing now we have the carriers sucking them… Read more »


The main issue is the HM2 there are only 30 and they have to cover carrier strike (14) the TAS equipped Type 23’s and training,so they will be heavily worked resulting in long term maintained problems.

Daniele Mandelli

I’m not military, but will have a go at that, happy to be corrected by the more knowledgeable 815 NAS forms or did form Ships Flights, assigned to each Frigate / Destroyer, for embarked Lynx, now Wildcat helicopters. The OCU unit for Wildcat, 715 NAS, carries out the MCT role too with 1 flight always ready. We had as many as 88 Lynx at one time, but with the demise of much of the escort fleet 28 is maybe enough for the available 19 escorts, taking into account those in refit. The Merlin force has reduced to 3 squadrons. Originally… Read more »


Isn’t the issue only going to get worse once the T31 come online? If they are going to be forward based around the world, that will mean helicopters will need to posted with them for long durations. At least now the T23’s are rotated from their home base mostly on shorter deployments. This would mean less available for rotation with our ships

Captain P Wash

Well Yes, but don’t let that Interfere with Government thinking. After all, They know best when It comes to the future of the UK and all who care for It.

What i’m seeing today just Boils my Piss.

Oh and, Bring back the Marathon Bar too.

Daniele Mandelli

You and me both captain.

Having derided and demonized Corbyn for years and called him Britain’s greatest security risk last week, May is now trying to get him to help her beat her own elected MPs, who were elected on a manifesto of leaving the EU, Customs Union, and Single Market, to stay in an EU becoming a federal Europe whom no one voted for, and which we had a referendum in which the vote was to leave!

You truly could not make it up and goodness knows what grass roots tory activists will think.


No they will have wildcat

John Clark

Captain and Daniele, “boils my piss” sums it up beautifully!

It’s hard to get to grips with the level of damage the Parliamentarians have done to our democracy of late.

The answer is simple, don’t vote for these self serving idiots ever again, both the Tories and Labour have wiped their arses with our democracy and flushed it down the toilet.

I will be voting and supporting whatever “proper” pro British (non racist), BREXIT supporting party that emerges from this chaos and will never vote for the Tories ever again.

Captain P Wash

That’s It then, I’m going to start up a new Brexit Party.

Let’s call It, “Boils my Piss” BMP.

Daniele Mandelli

Brexit party John. Where Nigel is I am.

John Clark

With you Daniele, joined up and await further news with great interest, as the party mobilises.

I will happily follow Nigel too…

Alan Garner

Without turning this into a politics forum; the problem with Farage’s new party is it splits the pro brexit vote. I think the main parties will be quietly very happy he has done this, for that very reason. Like most of their arrogance, however, I see it coming back to bite them on the arse in years to come but that will likely be too late, and who knows the level of damage will have been done by these despicable people by then? Closer to topic, I hope either Ukip/Farage party manage to overcome first past the post to gain… Read more »


nice cockpit upgrade but still light on ground suppression. what about 2in AG rockets similar to apache? theres two sponsens doing very little and they are (or were) wired up

Captain P Wash

It’s another “Built for but not with” Platform.


I am still not convinced turning RAF transport Merlins to Naval ones was wise.
I think we should have bought new Naval transport Merlins.
The conversion was expensive, risky & for only a relatively short service life.
Am I right in thinking that the hangar on QE/PoW can take CH-53K & V-22?

Daniele Mandelli

Gordon Brown put paid to that reportedly as Chancellor. There was a budget for a new helicopter called SABR Support Amphibious Battlefield Rotorcraft in the early to mid 2000’s to replace the ageing Sea King Commando HC4’s. In the never ending series of defence cuts undertaken by New Labour that helicopter budget was cut. So they took existing from the RAF instead, reducing our overall numbers in the process. At least the Merlins are all with a single service now. The moment Johnson Beharry VC turned his back on him for disrespecting the forces and refused his hand was brilliant… Read more »


Any reason why the Chinook cannot have folding blades? It would mean more can be stowed in the hanger.


The HC4 has a ramp. 95% of Electrics rewired. Different glass cockpit window. Flares, Chaff, sensors, cameras.