The UK Royal Navy's Merlin maritime helicopter made its operational debut in a theatre far removed from that for which the aircraft was conceived

A quarter of a century ago, when the Soviet submarine threat was the preoccupation of the UK Royal Navy, a requirement was raised for a new anti-submarine warfare (ASW) helicopter to operate from Invincible-class aircraft carriers and Type 23 frigates forming part of NATO's ASW striking force. Exploiting the extended detection ranges achieved by very low-frequency passive towed array sonar in the deep waters of the Greenland-Iceland-UK (GIUK) gap, this so-called Sea King Replacement (SKR) was envisaged as a sub-hunter supreme.

Fast forward to early 2003. After a long and complex gestation, the SKR has manifested itself as the Merlin HM1, a three-engined 16t class maritime helicopter based on the EH101 air vehicle developed by AgustaWestland. The last aircraft off the production line has just been handed over by prime contractor Lockheed Martin UK Integrated Systems, and 814 Naval Air Squadron (NAS) has undertaken the first front-line embarkations onboard the carrier HMS Ark Royal and the auxiliary oiler replenishment vessel RFA Fort Victoria.

But the world has moved on. The Cold War threat against which the aircraft was specified faded away some time in the early 1990s, as a result of which the Royal Navy's Merlin procurement was capped at just 44 helicopters. In the meantime, the service has re-oriented itself to address a new mission as a maritime enabler for joint force projection, a change accompanied by a new concept of operations and a shift away from blue-water operations into the confines of the littoral.

So is Merlin a legacy of the Cold War without a job to do? Not according to Lt Cdr Nick Dunn, commanding officer of 814 NAS. "What we have in Merlin is a multi-mission helicopter which is exceptionally robust and extraordinarily versatile," he says. "Its recent performance in Operation Telic [the UK's contribution to operations in Iraq] has demonstrated just how capable an asset it is."

So it was that a helicopter originally designed to operate in the cold waters of the GIUK gap saw its baptism of fire in the somewhat warmer climes of the Gulf. Four aircraft from 814 NAS embarked aboard RFA Fort Victoria in January this year, together with 12 pilots, eight observers and eight aircrewmen (including augmentees from 700M Operational Evaluation Unit [OEU] and 824 NAS). Another four personnel from the Warfare Support Centre at RNAS Culdrose (home to the Royal Navy's Merlin squadrons) were embarked to form an organic operational support cell.

"We were already familiar with operations aboard Fort Victoria, having embarked three aircraft aboard her during the latter part of 2002," says Dunn. "In some ways, operating from an AOR is preferable to a carrier in that it offers better habitability, an excellent ship/air interface and engineering spaces better suited to our needs. The hangar can accommodate three aircraft, leaving just one outside," he adds.

"Our only limitation was the SHOL [ship/helicopter operating limit] which was overly restrictive, having been based on read-across SHOL data from RFA Argus. That meant that while Fort Victoria has a two-spot flightdeck, we were only cleared to operate from the aft spot," says Dunn.

After sailing through the Mediterranean, the Suez Canal, Red Sea and Indian Ocean, Fort Victoria was deployed into the northern Gulf as part of the UK Amphibious Task Group. With no submarine threat, 814 NAS was primarily tasked as an anti-surface warfare asset. "The principal threat we faced was a swarm attack from small, fast inshore attack craft [FIACs]," says Lt Cdr Richard Creech, latterly senior observer with 700M OEU, who augmented 814 NAS for the duration of Operation Telic. "So our main role in theatre was force protection, patrolling a 'buffer zone' between 10nm [18.5km] and 30nm off the task force to look for unidentified radar contacts."

Specific tasking

Secondary roles comprised vertical replenishment, troop transport (between task force units rather than to the battle line), and long-range helicopter delivery service (HDS). "The aircraft was appropriately configured to reflect our specific tasking," says Creech. "With no ASW requirement in-theatre, the [AQS-950] active dipping sonar (ADS) was removed from the aircraft to free up space in the cabin. Eight seats were fitted plus racks for four stretchers, giving us a limited casevac capability.

"A stabilised 7.62mm general purpose machine gun [GPMG] was fitted in the forward starboard window. We flew with a port weapon station fitted, and SACRU [Semi-automatic cargo release unit] for loading and vertical replenishment," says Creech.

The waters around the northern Gulf were extremely crowded. "There was a lot of traffic, plus other contacts like mooring buoys and oil rigs," explains Creech. "But the Blue Kestrel radar performed very well, giving excellent resolution against FIAC-type swarm targets. This allowed us to obtain a superior surface picture and relay this across the force via Link 11.

"What was also significant was that Merlin was readily welcomed into the network by the US Navy link controller. The same could not be said of many other UK assets in theatre," adds Creech.

During the three weeks of hostilities, 814 NAS was tasked to provide one aircraft on station in the force protection role 24h a day. A second aircraft was typically flying six hours a day performing HDS transits (the longest being a 460km [250nm] leg from the top of the Gulf to Bahrain) or other utility operations. Taskings frequently required aircraft and crews to operate away from Fort Victoria for up to 10h.

Lt Cdr Colin Miller, senior observer with 814 NAS, says the Merlin's ability to manage concurrent tasks was impressive. "We could do force protection, link management and stretcher/troop transfer at the same time, and we had the legs. No other UK helicopter could do all this at the same time.

"Also, Operation Telic served to demonstrate that aircraft role change and reconfiguration could be achieved in about 14h, compared with about three weeks for the old Sea King HAS6," Miller says, adding: "Furthermore, when the ADS was later refitted it went back in with no integration problems whatsoever. The Sea King was historically a rather different story."

Flying under combat conditions allowed tactical and operational development to be driven forward at a rate unattainable in normal peacetime operations. "Merlin operational capability advanced three years in three months," says Miller. "We went through two full military aircraft releases and 14 service deviations to extend the aircraft operating envelope."

"We also achieved a number of equipment firsts," says Miller, adding: "For example, flying in full NBCD protective clothing; installation of the GPMG in the starboard window; the ability to carry a full fuel load; and clearance to operate Mode 4 IFF. We also received expanded cross-deck clearances to allow for operations with other ships in the task force."


There was general satisfaction with the performance and functionality of the Merlin weapon system. One limitation was the absence of an electro-optical sensor to allow positive identification of contacts at long range. A second high-frequency radio would also be welcome, and it is acknowledged that the current electronic support-measures system is not suited to the signal-dense littoral, having originally been designed to meet a "blue water" requirement.

Creech pays tribute to the air engineering effort on board Fort Victoria, saying: "Over 800h were flown in total during the hostilities, and only one sortie was lost to unserviceability. The air engineering team performed engine changes and main rotor gearbox changes at sea on condition each aircraft flew approximately 200h - there was no traditional 'hangar queen' giving up spares to keep the others flying."

However, it would be wrong to pretend that Merlin is not experiencing difficulties in its introduction to service. The acclaim that has greeted the aircraft's performance in the Gulf - which by common consent exceeded all expectations - has been tempered by continued issues surrounding aircraft sustainability and training output.

These problems stem largely from the concurrency of design, integration and production activities accepted by the original Merlin HM1 programme. As a result, aircraft have been delivered to varying modification states, complicating configuration management and fleet maintenance.

Spares shortages

In addition, spares consumption has exceeded original forecasts, with many components requiring replacement well in advance of their predicted life. The need to support 814 NAS during contingency operations in the Iraq theatre further exacerbated chronic shortages in certain line items, and has had a marked knock-on effect on aircraft serviceability (and flying hours) in the UK. It is acknowledged by the Royal Navy that only by increasing the number of flying hours will the service fully understand the spares provisioning and maintenance routines required to sustain the aircraft.

With maintenance man hours per flight outstripping initial predictions (which were predicated on the Sea King) the service has not been able to keep as many aircraft serviceable as it would like. This shortfall has in turn had an impact on the aircrew training pipeline through 824 NAS (the operational training squadron) at RNAS Culdrose.

To collectively address these issues, the key programme stakeholders - the Royal Navy, the Merlin Integrated Project Team, Lockheed Martin and AgustaWestland - are progressing a series of recovery measures. An in-service retrofit programme running over the next three years is intended to bring all aircraft up to agreed baseline standards, and incorporate a number of fixes identified from early operating experience.

Furthermore, the number of aircraft being introduced to support both training and front-line squadrons is being capped in the near term. This serves three goals: first, it alleviates the pressure on engineering staff; second, it will allow those aircraft flying to produce the data needed to mature aircraft sustainability and drive down maintenance man hours; and third, it scales back the requirement to generate additional aircrew. Both 814 NAS and 820 NAS will continue to operate just four aircraft apiece for the foreseeable future, and will not increase to their full six-aircraft complement until late 2006.

Those in the operator community see Merlin making a transition from a troubled infancy to a typically challenging adolescence, showing enormous promise but continuing to frustrate in certain areas. But the message from Merlin's front-line deployment to the Gulf is nonetheless overwhelmingly positive. "Merlin is maturing into a genuine multipurpose maritime patrol helicopter," says Dunn.

"What we want now is to further improve its versatility and develop a true 'plug and play' mission system architecture to allow additional capabilities to be brought aboard. For example, an electro-optical sensor system, a defensive aids suite and perhaps an air-to-surface missile in due course," says Dunn. "My hope is that the forthcoming Capability Sustainment Plus programme can deliver a package that fully exploits the enormous potential already demonstrated by Merlin in Operation Telic."

Source: Flight International