Rare insight into the Royal Navy’s Commando Helicopter Force

The reign of the RN Sea King HC4 comes to an end

They say that legends aren’t born, but made.The reputation of the Royal Navy’s Commando Helicopter Force (CHF) Sea King HC4 fleet has been forged in the heat of battle, under fire in every theatre of operation undertaken since the dark-olive chariots first entered service with their fearless, elite operators some 37 years ago.


Now standing at just seven ‘cabs’ on the 848 Naval Air Squadron flightline from a heyday of 40-plus, even those final seven machines will have more tales to tell than most assets the world over. Indeed, just one airframe – the 1981-build ZA298 – has been shot down three times in three different battle grounds.
But time waits for no man.


The reign of the scarred Sea King HC4s will end on Mar. 31 (as will the service of 848 NAS), with the passing of duty to the AgustaWestland Merlin fleet transferred from Royal Air Force ranks. These machines will have undergone a modification programme to suit the Royal Marine Commando troop deployment role, and also represent an inevitable leap in capability despite an expected total fleet of 25 modified airframes by 2020.

The writing was first on the wall for the Sea King HC4 replacement 2010 ahead of the five-year transition plan, with the 2010 Strategic Defence Review decree that all RAF Merlin HC3s would be transferred to the Royal Navy’s Commando Helicopter Force.


On Sept. 30, 2014, the Merlins were formally handed over and the first RN Merlin unit (846 NAS) stood up concurrently with its move from RAF Benson to RNAS Yeovilton on 26th March 2015.

A Merlin Life Sustainment Programme (MLSP) is underway, transforming the original Mk3/3As to HC4/4A standard, which will ‘navalise’ the helicopters and enable an amphibious role. This includes folding main rotor blades and tail boom, avionics upgrades (digital glass cockpit to the same standard as the RN Merlin Mk2 and Wildcats).


The first of the HC4 conversions are expected to be complete in September 2017 and will eventually produce 19 HC4 and five HC4A Merlins for 845 and 846 NAS.

In the meantime, seven interim standard machines are known as “HC3i” (“i” for interim), the first of which arrived at RNAS Yeovilton on 14th October 2015. This allows ship embarkation as a Sea King HC4 ‘gap-filler’. The Merlin HC3is have the folding blades, deck lashing points, fast-rope fixtures, upgraded undercarriage and an I-band transponder.


The role remains the same. The Fleet Air Arm’s Commando Helicopter Force, otherwise known as “Junglies,” will continue to provide amphibious transport of troops and supplies for 3 Commando Brigade into the heat of battle.


After the passing of 848 NAS and its Sea King HC4s, the CHF will have three squadrons, all based at RNAS Yeovilton; 845 NAS, which is currently standing up on the Merlin; 846 NAS, which is operational on the Merlin Mk3i, having transitioned from the Sea King in 2014 (and taking on the Merlin training role); whilst 847 NAS operates the Wildcat AH1 (moving from the Lynx Mk9A) in the recce, ISTAR, fire control, FAC and light transport roles. 848 NAS was actually disbanded in 2013 as the Sea King HC4 training squadron before being reformed in May 2015 to provide Sea King ops whilst 845 NAS transitioned to the Merlin.

The Maritime Counter Terrorism role will transfer to the 846 NAS from the end of March when 848 NAS disbands.


Capt Niall Griffin MBE is the Commanding Officer of the Commando Helicopter Force, with over 3,000 flying hours.

“Everybody that has flown the Sea King will recognise what a forgiving and enjoyable aeroplane it is to fly and how well it has served us right across every operational sphere that defence has been involved in for several decades. It has been truly remarkable and the CHF saying goodbye to the Sea King at the end of March is a momentous occasion.”


“All the way back to the Falklands and into every operational theatre the UK has been into, the HC4 ops have been relentless. We recently calculated that it has spent 25 years constantly on operations around the globe – probably an unparalleled contribution to UK defence – in such different conflict environs ranging from Northern Ireland and the Falklands to the challenges Bosnia and into the deserts of Iraq and Afghanistan… plus the ongoing peacekeeping and humanitarian missions. It has been a forerunner in helicopter warfare – it is versatile, forgiving and incredibly versatile.”


“‘It is hard to pick any highlight of the Sea King career. It’s just been the versatility that stands out. It has just been consistent and reliable all the way through every theatre and that in itself is a highlight. We have been able to build up a really good reputation as a force in our support of the Marines and the wider army, purely because of the Sea King. Any of us that have flown the type have fallen in love with it, it’s such a good aeroplane that we will all miss it. For me, flying the Sea King is like putting a comfortable pair of gloves on – I feel like the Merlin will catch me out if I don’t have a good instructor with me. The Merlin has a lot more downdraft, and just from a tactical point of view, the view out the front is very different due to the Merlin’s nose-up hover attitude.”


Capt Griffin relayed a typical war story that epitomised the ‘Junglie’.

“The CO of 848 was undertaking a under-slinging a load for troops up in the mountains of Afghanistan and he took somewhere in the region of seven rounds through the aircraft. To be frank, it would have been easier to list the things that were still working on the aeroplane rather than those that the rounds took out, but it was that good an aeroplane that he still managed to fly it away, recover to an operating base for it to be repaired and re-join the fight.”


“The Merlin is a far more modern aircraft. It’s larger, allowing for more troops in the back. In theory you can sit 27 troops in the back of a Sea King but they’d have to be pretty small and the Royal Marines I know are not small at all! The Merlin is supposed to be able to take 24, but pretty comfortably. It can also carry more weight, further and quicker than the Sea King. Add to that the avionics, systems and upgrades that are part of the package and we have a far more modern and up-to-date battle field helicopter on our hands to serve our Commando customers.”


“Whilst we will have around less half the number of Merlins compared to the days of the Sea King, the fleet is the right size to support our mission. When the Sea King was introduced the combat effectiveness and size of the Royal Marines was a lot bigger… In fact UK defence was a lot bigger – I can’t even recall just how many ships the RN had when I joined and the Sea King entered service – so the scaling down in terms of the number of aeroplanes is commensurate with the task that we now have. That, coupled with the increased capacity, means we just don’t need as many as we would have done with the Sea King.”


In a last defiant stand of reign, the last Sea King HC4s excelled themselves in reliability with up to five or six of the last seven airframes being fully airworthy on the line in the last few weeks. “They were there, just waiting to be flown, which is superb’ continued Capt Griffin. The Merlin is far more complex. The warning and management systems are far more intricate so we are on a learning curve from our friends down at RNAS Culdrose who have been flying the ASW Merlin HC2 for a number of years already. At the moment, the Merlin has not been as reliable as the Sea King in recent weeks, but that is only going to get better as we get more used to it. We have had some of the engineers from Culdrose come over from the grey Merlins as well so we are building our experience levels up and are confident that it will be as reliable as the Sea King.”


‘Junglie’ pilot Lt Aaron Cross is the Commander of ‘A Flight’ within 848 NAS.

“Our role right to the end is to provide tactical mobility to the Commando Force. If you were a Royal Marines Company Commander and you had your 100 or so Marines on the battle field, you could give us a call and we would move you around to where you wanted to be in the heat of battle. The tactical element means we can do that without being shot down by the enemy. It’s what we do.”


“The other role we undertake is load-lifting. We have a big, meaty hook that allows us to take vehicles, supplies, ammo to the troops on the ground around the battlefield. Rather than just landing and dropping troops out the door, we undertake fast-roping by dropping a thick rope out the side of the door to slide down with thick gloves on, or abseiling which is similar but undertaken at 200ft compared to 100ft for fast-roping. There is also parachuting, which is right up to the top of the aircraft’s service ceiling. But we don’t stop there, the inherent flexibility of helicopters allows us to perform CASEVAC, SAR or any myriad of other secondary roles, often employing our hoist which is rated at 600lb loading up to 200ft.”


Today’s motto at ‘848’ is ‘Provide tactical mobility in all weathers by day and night in all climatic conditions’. Originally forming in 1945 as a torpedo bomber squadron, 848 NAS won Battle Honours in Normandy (1944), Okinawa (1945), Japan (1945), Falkland Islands (1982) and Kuwait (1991), with operations tempo continuing in Bosnia, Northern Ireland, Iraq (Operation ‘Telic’), Afghanistan (Operation ‘Herrick’) and The Philippines (Operation ‘Patwin). Having operated the Sea King HC4 in the training role, the unit’s frontline position came about on May 1, 2013, when it stood up to take on the operational HC4 role from 845 NAS to allow the latter to convert to the Merlin without loss of capability.
Lt Cdr Mario Carretta, ex-CO of 846 NAS is a ‘Junglie’ legend and has ‘been there’ more than most with 5,000hrs amassed over 20 years of flying the type from Gulf War I in 1991 to Afghanistan in 2008.


“This is a sad moment for me; I have been flying the Sea King since 1989 and it is just so good at the many, many roles we’ve thrown at it. For me personally the defining moment of the HC4’s career came when I was CO of 846 NAS, and we had to prepare for operations in Afghanistan. As it stood, it wasn’t capable of doing the role so we upgraded to Carson blades and the AW five-bladed tail rotor – the enhanced performance that gave us allowed us to operate at 4-5,000ft in hot temperatures in-theatre. One of the best moments in my career was flying in formation with a Lynx and them asking me to slow down! The Sea King HC4 has done all that we have asked of it and never let us down. This versatile airframe could probably go on, but times change and the Merlin will be a great aircraft – the CHF fleet will benefit from the increased speed and lift capability of the new aircraft. The maintenance will be different, not necessarily better, as the Sea King is an old aircraft so it’s less complicated whereas the Merlin is newer but more complex to maintain.”


“On a typical FAA helicopter unit you would see around 10 aircraft, which fits for embark on HMS Ocean and airlifting a Company’ explained 848’s Lt Cross. As we’ve been drawing down our fleet, we currently seven airframes right now (as at Feb. 11). We will retire another two in the week commencing 15th February, and by the time we have our decommissioning parade we will have three Sea Kings left (from the remaining seven of ZA295/U; ZA298/Y; ZA299/D; ZE427/K; ZF116/WP; ZF117/X; ZG821/G).”


“One of those aircraft is known as ‘The King of The Junglies’, the famous ZA298, which was shot down three times in three different conflicts. It has not been possible to take that thing out of the sky and, accordingly, it will take pride of place in the Fleet Air Arm Museum here at Yeovilton, along with the panels that have been repaired from the RPG that went into the side of it. Plans for the other airframes are not secured yet, but some will go to HMS Sultan… and some might be auctioned off ‘with no careful owners” Lt Cross joked.

So March 2016 will see the crown of the Sea King HC4 pass to the Merlin and into the history books, but those books will remain particularly heavy with records of its illustrious reign as helicopter royalty….

Long live the King.


Image credit: RC-Pro Photography