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and Merlin Capability Sustainment Programme
Notes: Project designation: ST(S)6646 Status: In Service IntroductionThe EH101 is a large, three-engine'd helicopter capable of long-range autonomous operations. There are three main versions for naval, military and civilian use. The only version currently in Royal Navy use is the Merlin HM MK1 (formerly Merlin EH101), this is an Anti-Submarine (ASW) variant of the EH101 helicopter. The first aircraft was delivered in December 1998, to begin the replacement of the ageing ASW Sea King (Mk6), and the last of the 44 on order was somewhat belatedly delivered in late 2003. Merlin is designed to operate in all weathers from the flight decks of both large and small ships (Invincible class aircraft carriers and Type 23 frigates). It is powered by three Rolls Royce RTM 322 engines, is capable of speeds of up to 150 knots and has a range of 200 nautical miles. It can carry up to four homing torpedoes or depth charges, for use against threat submarines and can provide targeting information via datalink for the prosecution of surface threats. The Merlin retains all the secondary role capability of its predecessor, the Sea King, including loadlifting (vertrep), casualty evacuation, troop carrying and Search and Rescue (SAR). The aircraft officially entered RN service in 1999, the anticipated service life is 35-40 years. Based at Royal Naval Air Station (RNAS) Culdrose in Cornwall, 700M Naval Air Squadron, originally the Intensive Flying Trials Unit but is now the Operational Evaluation Unit (OEU) with three HM.1 aircraft. Next to form was 824 Squadron which commissioned in June 2000 with 8 aircraft and is responsible for training and converting crew to the Merlin. In October 2001 the first true front line Merlin unit was re-dedicated - 814 Naval Air Squadron - and became available for operations from HMS Ark Royal in May 2002. The next squadron to rededicate with Merlin was 820 in December 2003. Currently both 814 NAS and 820 NAS operate just four aircraft apiece, plans to increase them to their full six-aircraft complement by late 2006 seem unlikely to be fulfilled. The final squadron to recommission with Merlin was 829, formed on 21 October 2004 with 3 aircraft transferred from 824 . It provides ship flights for Type 23 frigates, initially it operates aircraft for HMS Lancaster, Monmouth and Westminster, but eventually it will provide six flights from a strength of eight aircraft. All aircraft assigned to this squadron will be configured to be compatible with the Prism deck landing system fitted to the flight deck of the frigates. It is unclear whether 824 will be built up to 12 aircraft as earlier planned, or will remain at 8 or 9. The operational debut of the Merlin was made in early 2003. Four aircraft from 814 NAS embarked aboard RFA Fort Victoria in January year, together with 12 pilots, eight observers and eight aircrewmen (including augmentees from 700M Operational Evaluation Unit [OEU] and 824 NAS). Fort Victoria was deployed into the northern Gulf as part of the UK Amphibious Task Group for Operation Iraqi Freedom. With no submarine threat, 814 NAS was primarily tasked as an anti-surface warfare asset against swarm attack from small, fast inshore attack craft [FIACs]. Secondary roles comprised vertical replenishment, troop transport (between task force units rather than to the battle line), and long-range helicopter delivery service (HDS). 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, to give a limited casevac capability. A stabilised 7.62mm general purpose machine gun [GPMG] was fitted in the forward starboard window, and a semi-automatic cargo release unit for loading and vertical replenishment.
Development HistoryIn the early 1970s the Royal Navy recognised that there would be a requirement to replace the Sea King towards the end of the century. This led to the signing in 1979 of a Memorandum of Understanding between the Italian and British Governments to co-operate in the joint development of a medium lift helicopter to fulfil the roles of shipborne Anti-Submarine and Anti-Surface Warfare, military utility and civilian transport. Agusta and Westland formed a 50/50 joint company called EH Industries to manage the program in 1980. In its original Staff Requirement, the Royal Navy specified some key performance markers for a Sea King replacement. The first was speed and endurance to allow operations at extended ranges and to permit quick reaction to, and attack on, submarine targets. The second feature was an integrated mission system to process data from a suite of sensors to give the helicopter an independent capability to search for, locate and attack targets. Versatility was a third key requirement to enable the helicopter to carry out a wide variety of roles and respond quickly to emergency tasking in flash points around the world. Agility was the final characteristic. The helicopter had to have sufficient power, manoeuvrability and control margins to allow safe operations from frigate-sized flight decks in demanding weather conditions, day and night. The EH101 program was given the go-ahead by the British and Italian Governments with the signing of an agreement on January 25th 1984. This provided for joint funding of the project through development to the production stage. The fourth UK/Italian MoU was signed on September 30th 1991, which started the industrialization phase. The Royal Navy's Merlin purchase was to meet Staff Requirement (Sea) 6646, which called for 66 aircraft. The Merlin may also be bought to fulfil a staff requirement for a Support Amphibious and Battlefield Rotorcraft (SABR) to replace the RN’s Westland Commando Sea King HC4s and the RAF’s Search and Rescue (SAR) Sea King Mk3s and Puma HC1 Support Helicopters; and also as a Future Organic Airborne Early Warning aircraft to replace the Sea King AEW.7. In 1991 GKN Westland ceased to be prime contractor for the RN's machines, and Loral ASIC were awarded the contract. Loral was later taken over by Lockheed Martin. The UK Strategic Defence Review, published in July 1998, stated that the Royal Navy would not receive more than the 44 Merlin HM.1s already on order. In July 2000 GKN Westland and Agusta agreed to merge their helicopter business, with the resulting company being called "AgustaWestland".
Merlin Capability Sustainment Plus (Merlin CSP) program. In June 2003 Lockheed Martin UK Ltd, teamed with Westland Helicopters Ltd (now AgustaWestland), was awarded by the MOD a 18-month Assessment Phase study worth approximately £18 million to evaluate obsolescence issues with the Merlin HM1, and assess possible upgrades. On 10 November 2004, Lockheed Martin UK Ltd submitted its proposal for what was then termed the Royal Navy Merlin Capability Sustainment Plus (Merlin CSP) program. Lockheed is proposing an update the Merlin HM Mk 1 computer architecture and flight controls, and to install a multi-mission sensor suite including an electro-optical sensor. The Merlin CSP is expected to better adapt the Merlin to the littoral underwater and surface battlespace and enhance the utility of the helicopter in other roles such as supporting civil authority. It is also hoped that the whole-life costs will be reduced and the overall reliability of the systems will be increased substantially. In addition the aircrafts weight will be decreased, thereby allowing an enhanced payload or time on station. The upgrade addresses obsolescence issues in the Merlin mission suite by adopting an open systems computer architecture ready for both technology refresh (processing power and speed upgrades) and technology insertion (new sub-systems and functions). The new computer architecture will have processing capacity and memory size more than 250 times greater than current Merlin systems. An improved human machine interface (HMI) also promises reduced operator workload - as mission systems become more versatile so the need for intuitive interfaces increases. Considerable attention will be paid to reducing operator workload whilst making simultaneous control of multiple and diverse missions a realistic possibility. The Merlin CSP project is being given enhanced importance by the Royal Navy because of the comprehensive review of the MOD’s helicopter requirements being currently undertaken by the Future Rotorcraft Coherency forum. The forum is trying rationalize projects that total nearly £4.5 billion in to a solution that fits within the £3 billion budget available over the next decade for new helicopters. There is considerable speculation that the Royal Navy’s Surface Combatant Maritime Rotorcraft (SCMR) project will be the principle victim of the review, leaving no specific replacement for the versatile Lynx HAS.3 and HMA.8, and the RN thus increasingly reliant upon the Merlin to fill in a broad range of roles as the Lynx begins to leave service from about 2009. If as expected the MOD decides to proceed with Merlin CSP, Lockheed Martin will be the designated prime contractor and lead systems integrator in a strategic business alliance with the Merlin’s air vehicle designer and manufacturer, AgustaWestland. In November 2005, the Minister for Defence Procurement, Lord Drayson, decided against approving the Merlin CSP programme despite the backing of the Defence Ministry's Investment Approval Board. However an announcement was made on 12 January 2006 that a Merlin Capability Sustainment Programme (MCSP), contract £750 million had been awarded to Lockheed Martin UK. The overall programme is expected to cost some £850M and "will ensure that the Royal Navy's EH101 Merlin Mk1 retains its position as the world's most capable maritime patrol helicopter". The Merlin CSP is now being considered as part of the Defence Ministry's overall future rotorcraft capability (FRC). According to Flight International magazine, contained within a £750 million Merlin Capability Sustainment Programme (CSP) deal awarded to prime contractor Lockheed Martin UK, the work will include the integration of new avionics, communications and navigation equipment, a new open architecture mission system and fly-by-wire controls from 2010. AgustaWestland, now a Finmeccaninca company, has said that it had been awarded a major contact worth approximately £400 million for the upgrade of 30 EH101 Merlin HM Mk1 helicopters, with an option for a further eight. To be conducted in Yeovil, the modifications will improve the aircraft’s BAE Systems Blue Kestrel maritime search radar, particularly its ability to track targets in the littoral environment. The deal, which contains an option to upgrade a further eight aircraft, reflects the objectives of the UK’s Defence Industrial Strategy white paper, which seeks to safeguard national capability in strategically important sectors of the defence industry, including rotorcraft. Published last month, the document says the Merlin CSP project will “enable the cost-effective management of obsolescence on an aircraft that has components and design features that are becoming difficult to support”. The focus of the programme is to enable cost-effective management of future obsolescence of the current aircraft’s equipment and systems, and to introduce an Open Systems Architecture (OSA) into the helicopter. The UK Ministry of Defence expects the upgrade to deliver long-term cost reductions of £575 million through the removal of system obsolescence and reduced support costs. The RN currently (Jan 2006) operates 42 Merlin HM1s for anti-surface and anti-submarine warfare tasks from the 44 delivered in 1998-2002. Tthe CSP-standard upgraded Merlin will enter service in December 2013, with the RN expecting it to stay in service until 2029. The Merlin HM Mk.1 fleet will be progressively upgraded from 2010 and will see the updated and improved aircraft come into service from 2013. The work to upgrade the aircraft will take place at AgustaWestland’s Yeovil facility in the UK. Costs & Major Milestones
Major Milestones:
DimensionsOverall folded size of the EH101 is only marginally larger than that of the SH-3 Sea King, but because of the arrangement of the undercarriage the 101 will be able to use less deck space than its predecessor.
EnginesThe development aircraft were powered by three General Electric CT-6 turboshafts. Production aircraft for the RAF and RN are equipped with the Rolls Royce Turbomeca RTM 322. The transmission cannot handle the full output of all three engines, but if one fails the remaining two engines have sufficient power to keep the helicopter flying. RN aircraft have a Hovering In-Flight Refuelling (HIFR) point in the cabin, just aft of the cargo door. AvionicsExcepting the naval/military mission equipment, the EH101 cockpit is common to all versions. Six 18x15cm multifunction colour displays replace the traditional dials. The avionics system is based on two MIL STD 1553B digital databuses which link the basic aircraft management system and mission systems. The latter, based on dual redundant mission computers, handles all sensors and displays and controls the mission bus.
The EH101 is fitted with Health and Usage Monitoring (HUM) equipment, which will monitor aspects of rotor head, transmission and mission performance, and presumably warn the pilot of any problems. HUM and the mission systems combine to reduce crew workload, an essential requirement given the long and complex missions which the helicopter undertakes. The Ferranti Blue Kestrel radar is fitted to the underside of the Royal Navy's aircraft. Blue Kestrel's 360° scan and multiple target-tracking facility make it far more capable than the the Sea Spray radar fitted to the Lynx. British aircraft also carry "Orange Reaper" ESM equipment. The ASQ903 acoustic processor processes data returned by dunking sonor or sonobuoys. Royal Navy Merlins are equipped with the Thomson Marconi Sonar FLASH (Folding Light Acoustic System for Helicopters) active dipping sonar. This comprises a submersible unit with a low frequency transmitter, and a receiving array of 12 folding arms. FLASH is suitable for both deep and shallow water operations, and is capable of operating at depths down to 700m. The EH101 has a BAe ring laser gyro as its primary navigation aid. It also has the Plessey PA5015 radar altimeter.
Performance
The EH101 Merlin/Type 23 Frigate weapon system has been designed to provide maximum operational efficiency by reducing crew workload while maintaining a very high state of readiness and aircraft availability. Coupled with these attributes, the Royal Navy's reduced manning philosophy has driven the cockpit design towards operation by a single pilot. From a pilot's standpoint, the aircraft is fully capable of being flown solo. The handling qualities are exceptional throughout the flight envelope, the autopilot modes permit hands-off flight for most of the mission, and the avionics are in some cases triple redundant with benign failure modes. EH101 can operate in sea state 6, in up to 50 kts cross winds, to allow its parent Type 23 frigate to continue monitoring its towed sonar array without the need to turn into wind. Once on deck, the rotor system can generate negative thrust while the helicopter is made fast (while) by engaging a rapid securing device called PRISM which consists of a "harpoon" in a grid on the deck. PRISM interfaces with a semi-automatic handling system for aircraft moves and weapon loading. Merlin LinksNote: Links open in new windows GKN Westland Helicopters - EH101 News Defence Procurement Agency - Merlin MH Mk1 Naval Technology - Merlin - ASW/Transport Helicopter Last revised: 4 February, 2006 |
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© 2004-8 Richard Beedall unless otherwise indicated. |
