846 NAS return to RNAS Yeovilton - Image © Lewis Gaylard

846 NAS return to RNAS Yeovilton – Image © Lewis Gaylard

With the retirement of the Sea King HC.4 set for March 2016, Commando Helicopter Force (CHF) has taken a significant step in the long transition phase to, ultimately, the Merlin HC 4.

Lewis Gaylard reports for Flightline UK from RNAS Yeovilton as 846 NAS returned with their Merlin HC3 helicopters. All photography by the author. 

Thursday 26th March witnessed the return of 846 Naval Air Squadron (NAS) to its ‘spiritual’ home of Royal Naval Air Station (RNAS) Yeovilton in Somerset. Flying in formation the six AgustaWestland AW101 Merlin HC.3/3A troop transport helicopters returned home after three years based at RAF Benson in Oxfordshire. Their route included JHC Command, Salisbury Plain and over the factory airfield of AgustaWestland in Yeovil before ‘running in’ to Yeovilton.

The first complete Royal Navy ‘Commando’ aircrew graduated on the Merlin at RAF Benson on 16th November 2012. Training for the ‘Jungly’ ground crew was also undertaken at Benson and well over a Hundred have so far converted to Merlin.

The commanding officer of 846NAS, Lt Col Derek Stafford is proud of the squadrons new aircraft and being the first ‘Jungly’ Merlin CO and commented; ‘I’m deeply honoured and truly humbled to be not only the first Commanding Officer of the Squadron in the Merlin era, but also to have had the privilege of leading the return of 846 back to its spiritual home here at Yeovilton.

We have already operated the Merlin in Jordan last year and earlier this year we deployed to RNoAF Bardufoss in Norway for Exercise Clockwork 15. The immediate plan for the squadron is to maintain a Very High Readiness posture so we are capable, and ready to deploy worldwide should the need arise. These challenges will be met with the same qualities of determination, professionalism and cheerfulness in the face of adversity that were displayed by our forebears and are encapsulated in the ‘Jungly’ ethos.

The transition of the RAF’s Merlin Force to the RN’s Commando Helicopter Force (CHF) was announced in the Strategic Defence & Security Review (SDSR) in 2010. The 25 Merlin HC3/3A aircraft will undergo a Merlin Life Sustainment Programme (MLSP) at an estimated cost of £445 million which includes converting the current HC.3/3As into the HC.4/4A configuration.

This not only provides ship optimisation with folding main-rotor blades and tail boom, but more importantly, a life sustainment package to solve obsolescence issues. It will also provide an avionics upgrade to provide a ‘glass’ cockpit common to the RN’s Merlin HMA.2 and similar to the AW159 Lynx Wildcat. The HC.4/4As will then have a full operational capability out to 2030.

The return of 846 NAS to Yeovilton will see their ex-RAF Merlin HC.3s will be converted to an initial embarked capability and designated Merlin iHC.3s. These aircraft will bridge the operational capability gap between the retirement of the Sea King HC.4s on 31 March 2016 and the arrival of the first Merlin HC.4 in September 2017.

The seven Merlin iHC.3s aircraft will be equipped with folding main rotor head but no tail fold. The main rotor fold function will be able to be operated by ground crew. New fast rope points, strengthened undercarriage and new lashing points for deck operations will also be introduced. The first aircraft is due to be delivered in September and all seven aircraft delivered by 1 April 2016 to meet the Sea King out of service date (OSD).

The MLSP will be conducted in two main phases. Phase 1 will convert nine Merlins to the HC.4 standard, with all nine aircraft having a full operational capability by 29 February 2022. Phase 2 will see the remaining Merlin HC.3s/HC.3As and seven iHC.3s enter the MLSP to eventually see CHF operating 25 Merlin HC.4s/HC.4As (19 HC.4s and six HC.4As), with a full operating capability predicted for 31st March 2022. The MLSP will make the Merlin HC.4/HC.4A almost identical, and both aircraft will operate within ether of the two front-line squadrons.

Captain Niall Griffin, Commanding Officer of the Commando Helicopter Force said: “The arrival today of six Merlin helicopters of 846 NAS from RAF Benson to RNAS Yeovilton marks another milestone in the transition of the Commando Helicopter Force from the Sea King to the Merlin. 


“Over the next year we will see a gradual build up of Merlins here in Somerset, as we relocate from Benson. By Easter next year both front line Merlin squadrons, 845 NAS and 846 NAS, will be co-located here at RNAS Yeovilton, once more being reunited with 847 NAS and their new Wildcat battlefield helicopter.

“Whilst there are clearly exciting times ahead, it is important to look back on the aircraft which the Merlin replaces. When the Sea King Mk4 retires next March, it will have been in service for some 37 years, serving in more Operational Theatres than any other Fleet Air Arm aircraft.

“The Force is currently very busy and looking further ahead to the autumn, CHF will be participating in the Royal Navy’s Flagship deployment to the Mediterranean, Cougar 15, as well as training with 3 Commando Brigade Royal Marines in the Mojave Desert, California. Both represent excellent training and will continue to keep us at Very High Readiness as a Force.” 

The Commando Helicopter Force’s transition from the Sea King HC4 to the Merlin will continue at RAF Benson when 845 Naval Air Squadron stand up in place of 28 (Army Cooperation) Squadron RAF in May 2015. At this point 848NAS will re-commission at Yeovilton and will have the honour of flying the remaining Sea King to its OSD. When fully operational, 845 NAS will return home to Yeovilton to reunite all the CHF Squadrons.