MERLIN MK1
 

Merlin HM MK1 (formerly Merlin EH101) 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). The 44th and final aircraft was delivered in December 2002.

The collaborative programme began in 1979 through EH Industries - the company formed by Agusta of Italy and GKN Westland in the UK. Designed in Western Europe, it is the largest collaborative helicopter project in history.

In 1991 the United Kingdom selected IBM-Aerospace Systems Integration Corporation (ASIC) (subsequently Loral-ASIC, now Lockheed Martin ASIC (LMA)) as prime contractor to complete Royal Navy development, integration of the Mission System and production of 44 aircraft. Since then progress has been made on the programme through the award of the Collaborative Production Investment contract in March 1992 to EH Industries. Contracts were also awarded to Lockheed Martin ASIC for the Merlin Training System (MTS) in July 1994, and the Merlin Support and Spares Availability System (MSSAS) in July 1996.

The first flight by a production Merlin was on 6 December 1995 and the first mission system fitted Merlin Mk1 flew in January 1997. Royal Navy Intensive Flight Trials began on schedule in December 1998.

The Royal Navy operate the aircraft from 4 aircraft Squadrons and single aircraft flights, with worldwide detachments from a range of ships including CVS, RFAs and Type 23 frigates. An 8 aircraft training Squadron and full motion simulator is based at RNAS Culdrose in Cornwall. The aircraft was effectively employed on Force Protection Duties during the Gulf War.

Work is currently underway on a significant programme to sustain the capability of the in service Merlin Mk1 aircraft to Out of Service Date (OSD) through the Merlin Capability Sustainment Programme (MCSP).


The aircraft has a state-of-the-art, integrated mission system, which processes data from an extensive array of on-board sensors, giving Merlin an independent capability to search for, locate and attack submarine targets. It is this autonomous capability which makes Merlin unique among ASW helicopters.

The aircraft and its mission system are managed by two computer systems, linked by dual data buses. The cockpit is designed for operation by a single pilot, with the auto-pilot allowing for hands-off flight for most of the mission.

Normally flown by a crew of three - pilot, observer and aircrewman - Merlin is equipped with the Thomson-Marconi active "dunking" sonar which gives enhanced submarine detection ranges, and the GEC Marconi AQS 903 acoustic processor. All crew stations can access the management computers and operate the tactical displays. These are fed by the Marconi Blue Kestrel radar which possesses full 360-degree coverage and an ability to Track-While-Scan surface contacts. It can also pass tactical information via a datalink to other participating units; a significant capability which has not been utilised by maritime helicopters before.

Based at Royal Naval Air Station (RNAS) Culdrose, Cornwall, 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, casualty evacuation, troop carrying and Search and Rescue.
 

The physical characteristics of Merlin are:

All-up weight = 14,600kg
Rotor diameter = 18.6m
Length = 22.8m
Width = 4.55m The anticipated service life of the aircraft is 35-40 years.

The overall total cost of the programme = £4.65 billion.

The Prime Contractor is Lockheed Martin ASIC. The aircraft is a development of the military Naval version of the Anglo-Italian EH101 and has a degree of commonality with the Medium Support Helicopter variant, the Merlin HC Mk3. The EH101 is manufactured by Agusta Westlands which is an Italian / UK based company. The International Development Programme (IDP) under which the EH101 was developed was an Anglo-Italian collaborative programme. Each nation is currently procuring variants of the baseline helicopter. USA, Canada, Denmark, Portugal and Japan have also procured variants of the EH101.

MERLIN MK3

Staff Requirement (Air) 440 for a Medium Support Helicopter (MSH) was approved in March 1994. In March 1995, the Secretary of State announced that 22 EH101 Support Helicopters would be procured together with a smaller number of Chinooks, to meet the MSH requirement. The SH(EH101) contract was awarded in June 1995.
 

SH(EH101), designated the Merlin HC Mk3, fills a capability gap between Chinook and Puma. Based on the military utility version of the Anglo-Italian EH101, Merlin Mk3 is designed to operate by day and night, in hot and high or cold and icing conditions undertaking a wide variety of missions.
 

Designed to carry 24 troops in crash attenuating seating, fitted with active noise reduction (ANR) headphones.

Under slung loads up to 4.1 tonnes can be carried. A range on internal fuel in excess of 1000km, the operating range can be extended by role fit extended range tanks or an air to air refuelling capability, continuous operations are possible. It will support ground forces in a wide range of operational scenarios, including combat search and rescue, in National, NATO and UN operations. A range of role-fit and portable support equipment is also available to further tailor the aircraft for special operations.

A detachment of 6 Merlin aircraft from 28 (AC) Squadron has been the major element of the JHC contribution to post-war support helicopter operations in Iraq. Operating in the desert, in extremely arduous conditions, the aircraft has exceeded every expectation of performance, reliability and availability.

The Merlin HC Mk3 is a significant advance in capability and also reflects the progress in both roles and capabilities of support helicopters. The Merlin HC Mk3 has a single main rotor configuration powered by three uprated Rolls Royce Turbomeca RTM322 engines. It has an all up take off mass of 14.6 Tonne, maximum speed of 167 knots vne and range on internal fuel in excess of 1000km. The operating range can be extended by using internal ferry tanks or an air to air refuelling capability; continuous operations are possible.

The aircraft is designed to carry 24 troops in crash attenuating seating, fitted with active noise reduction (ANR) headphones. The seats can be folded away and a range of cargo or small vehicles loaded via a rear ramp or side door. A cargo winch and roller conveyor for palletised freight are integrated. Under slung loads can be carried.

The aircraft incorporates the latest technology in composite structures, multiple system redundancy and enhanced health and usage monitoring to minimise life cycle costs. Active control of structural response (ACSR) struts reduce vibration at all speeds. It is designed to be highly reliable, maintainable and supportable away from its normal operating bases.


Pilot workload is eased with automated flight control and aircraft management, integrated GPS/INS based navigation, extensive communication systems and Night Vision Goggle (NVG) compatible electronic instruments and displays.

All of the aircraft will be fitted with a comprehensive Defensive Aids Suite (DAS) that will include a Radar Warning Receiver (RWR), a Laser Warning Receiver (LWR), Chaff and Flare dispensers and a Directional Infra-Red Countermeasures (DIRCM) system. A limited number will also be fitted with Forward Looking Infra-Red (FLIR).

3g agility and a low noise signature enhance effectiveness and minimise environmental impact. Wire strike protection, armoured crash attenuating crew seats, automatic fire protection systems and the defensive aids provide enhanced survivability. 

Work is currently underway to provide a new armament option onboard the aircraft.

Including support and role equipment the procurement programme is expected to cost £750M.

The First flight took place on 24 December 1998.

Logistic Support Date was achieved in Nov 99.

Aircraft RAF02 was delivered to DERA Boscombe Down on 19 Jan 2000 to commence Military Aircraft Release trials.

ISD (delivery of six aircraft) achieved in - Jun 2000
Final aircraft of 22 delivered November 2002

The Prime Contractor is Augusta-Westland Helicopters Limited which is an Italian / UK based company. The aircraft is a development of the military utility version of the Anglo-Italian EH101 and has a degree of commonality with the Naval variant, the MERLIN HM Mk1.

The International Developer Programme (IDP) under which the EH101 was developed was an Anglo Italian collaborative programme. Each nation is currently procuring variants of the baseline helicopter. USA, Canada, Denmark, Portugal and Japan have also procured variants of the EH101.