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
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
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.
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
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
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.
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
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
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
Including support and role equipment the procurement programme is expected
to cost £750M.
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.
INVOLVED WITH THIS PROJECT
EADS - Test Equipment, ATE upgrades