Royal Air Force Merlin

The AgustaWestland EH101 is a medium-lift helicopter originally developed as a joint venture between Westland Aircraft in the UK and Agusta in Italy for military applications but also marketed for civil use.

In 1977, the UK Ministry of Defence issued a requirement for a new anti-submarine warfare (ASW) helicopter to replace the Royal Navy's Westland Sea Kings. Westland responded with a design called the WG.34 that was approved for development. Meanwhile, the Marina Militare (Italian Navy) was also seeking a replacement for its (Agusta-built) Sea Kings, leading Agusta to a series of discussions with Westland about the possibility of a joint development. This culminated in the joint venture being finalised in November 1979 and a new company (EH Industries) being formed to manage the project the following year. EH is an abbreviation for Elicottero Helicopter, incorporating both the English and Italian words for "helicopter." As the design studies progressed, EH became aware of a broader market for an aircraft with the same broad capabilities required by the British and Italian navies, leading to a more generalised design that could be customised for specific customers and applications. After a lengthy development, the first prototype flew on October 9 1987. EH Industries no longer exists, having been incorporated into the parent when the two companies merged.

The nomination 'EH101' is actually a typographical error that stuck: the aircraft was originally designated EHI (Elicottero Helicopter Industries) - 01

The aircraft was manufactured at the AgustaWestland factory in Yeovil.

The military version of the EH101 is powered by either three Rolls-Royce Turbomeca RTM322 turboshafts (UK, Canada, Japan, Denmark and Portugal), or three 1,491 kW General Electric CT7-6 turboshafts (Italy). Engine inlet particle separator systems provide protection when operating in sandy environments. Each engine is supplied by a separate self-sealing fuel tank using dual booster pumps. Each tank holds 1,074 litres of fuel. A fourth tank acts as a reservoir supply, topping up the main tanks during flight. A fifth transfer tank can be added to increase range, as can airborne refuelling. The engines power a 18.59 metre diameter five bladed main rotor. The rotor blades are constructed from carbon/glass with nomex honeycomb and rohacell foam, edged with titanium alloy. Computer control of the engines allows the EH101 to hover reliably in winds of over 80 km/h.

The modular aluminium-lithium fuselage structure is damage and crash resistant, with multiple primary and secondary load paths. Active vibration control of the structural response (ACSR) uses a vibration-cancelling technique to reduce the stress on the airframe. The EH101 is rated to operate in temperatures ranging from -40 to +50 degrees C. High flotation tyres permit operation from soft or rough terrain.

The cockpit is fitted with armoured seats for the crew, and can withstand an impact velocity of over 10 m/s. Dual flight controls are provided, though the EH-101 can be flown by a single person. The pilot's instrument displays include six full colour high-definition screens and an optional mission display. A digital map and Forward Looking Infrared system display can also be installed.

A chin turret can be fitted with a 12.7mm machine gun. The stub wings have hardpoints for rocket pods. The EH101 is equipped with chaff and flare dispensers, directed infrared countermeasures, infrared jammers, missile approach warners, and a laser detection and warning system. The HM Mk1 model can carry 4 Sting Ray torpedoes or Mk 11 Mod 3 depth bombs, though at present cannot use Sea Skua missile.

The military version EH101 can accommodate 30 seated or 45 standing combat troops and their equipment. Alternative loads include a medical team and 16 stretchers, cargo pallets. The cabin floor and rear ramp are fitted with flush tie-down points, a roller conveyer for palleted freight and a cargo winch. The ramp can take a 3,050 kg load, allowing it to carry vehicles such as Land Rovers. An cargo hook under the fuselage can carry external loads of 5,440 kg. A rescue hoist and a hover trim controller are fitted at the cargo door.

The navigation system includes a GPS and inertial navigation system, VHF Omnidirectional Radio range (VOR) instrument landing system (ILS), tactical air navigation (TACAN) and automatic direction finding. The EH101 is equipped with helicopter management, avionics and mission systems linked by two 1553B multiplex databuses. A Smiths Industries OMI SEP 20 automatic flight control system provides dual redundant digital control, giving autostabilisation and four-axis auto-pilot operation.

The Royal Navy's final order was for 44 ASW machines, originally designated Merlin HAS Mk.1 but soon changed to Merlin HM Mk.1. The first fully operational Merlin was delivered on May 17 1997, entering service on June 2 2000. All aircraft were delivered by the end of 2002.

These aircraft are commonly regarded as the most advanced air-born ASW platforms in the world.

The UK is considering the Merlin as a replacement for the Westland Sea King ASaC7 in the Airborne Early Warning (AEW) role.

The Royal Air Force ordered 22 transport helicopters designated Merlin HC3, the first of which entered service on December 11 2000.

The Merlin HC3 is operated by No. 28 Squadron RAF, based at RAF Benson. The type breaks new ground for the RAF in being equipped with an inflight refuelling capability, however due to the lack of a suitable UK tanker aircraft, this capability is not cleared for use.

The first operational deployment was to the Balkans in early 2003. They are currently deployed to southern Iraq as part of Operation Telic.

The first Italian Navy production helicopter (M.M.I. 01) was first flown on the 4th October 1999 and it has been officially presented to the Press on the 6th December 1999 at the Agusta factory. The delivery to Italian Navy started at the beginning of 2001. The Italian Government has signed a contract to procure 16 EH101 helicopters that will be delivered to Italian Navy in the following variant: 8 anti-surface and anti-submarine (ASW) aircraft; 4 early-warning (AEW) aircraft; 4 utility aircraft.

Canada has had a troubled history with the EH101. Following the lead of the UK and Italy, the Canadian government placed a $4.4 billion (CAD) order in 1987 for 48 (later 42) EH101s to replace the Canadian Armed Forces's CH-124 Sea Kings and CH-113 Labradors. These were to be assembled in Canada under the designations CH-148 Petrel (33 originally, reduced to 28) and CH-149 Chimo (15) in the anti-submarine warfare (ASW) and air/sea search and rescue (SAR) roles respectively. The whole programme was cancelled, however, after a change of government in 1993, leading to the payment of $500 Million in cancellation penalties.

In 1998, the Canadian government announced that the CH-113s would now be replaced by a new search-and-rescue variant of the EH101, carrying the designation CH-149 Cormorant. Unlike the Petrel/Chimo contract, these fifteen aircraft were to be built entirely in Europe. The first two aircraft arrived in Canada in September 2001 and entered service the following year.

The first operational CH-149 flight occurred in 2002 when a Cormorant of 442 Squadron performed a medevac from a merchant ship 200 km offshore in Hecate Strait. An even more dramatic demonstration of Cormorant capabilities occurred in late 2002 when a 103 Squadron CH-149 successfully flew a 1,200 km round-trip rescue mission to a container ship off Newfoundland. Two refuelling stops at the Hibernia oil platform were required.

On July 13, 2006, a Canadian CH-149 Cormorant crashed of the coast of Nova Scotia killing 3 personnel and injuring 4 during a joint search and rescue exercise. This helicopter belonged to 413 Transport and Rescue Squadron. An investigation into the cause of the crash is ongoing. At this point, the Military investigators have ruled out mechanical failure of the tail rotor and all normal operations have been restored.

When it became obvious that the Sea Kings were in need of immediate replacement, the EH101 was again part of a Canadian competition (the Maritime Helicopter Project), versus the Sikorsky H-92, for a total price tag of $5 billion. The Sikorsky entry won the competition on July 23, 2004; it is to be known as the CH-148 Cyclone.

Also in 2001 AgustaWestland signed a deal with Lockheed Martin and Bell Helicopter Textron to market the aircraft in the US under the designation US101. It competed for and won the VIP and "Marine One" Presidential transport roles currently carried out by H-3 Sea King or the smaller VH-60 White Hawk. The US101 will be built in the United States and fitted with largely American systems and equipment, General Electric turboshafts for example.

On 28 January 2005, the US101 was announced as the winner of the contest to supply the next Marine One helicopter for the transportation of the President and other VIPs. In doing so, it beat the Super Hawk, Sikorsky's contending entry, and became the first non-Sikorsky helicopter to fulfill the Marine One role since 1957. The order is for 23 aircraft, to equip the Marine One squadron, HMX-1. These aircraft will be given the military designation VH-71A.

The Tokyo Police became the first civil customer for the type when they purchased a single example in 1998. In 2003, the Japan Maritime Self-Defense Force ordered for 14 aircraft to use in the MCM (Mine Cleaning Mission) and transport role. MCH-101, JMSDF's temporary name, is going to replace MH-53E, for MCM and S-61, for support of the Japanese Antarctic observations.

The Portuguese Air Force acquired 12 of such aircraft in three different versions: 6 in SAR, 4 in CSAR and 2 in SIFICAP (Fisheries Control) configurations. All versions are NVG capable, the CSAR versions adding a "Defensive Aids Suite" (DAS), weapons carriage and "Air to Air Refueling" (AAR), while the SIFICAP carries the APS-717P radar.

In 2001 Denmark announced the purchase of EH101 for SAR duties (8 units) and tactical troop transport (another 6 units). The last of the 14 EH101's will be delivered in 2006 and will become operational early 2007.

General characteristics:

* Crew: 4
* Capacity:
o 30 seated troops or
o 45 standing troops or
o 16 stretchers with medics
* Length: 74 ft 10 in (22.81 m)
* Rotor diameter: 61 ft 0 in (18.59 m)
* Height: 21 ft 10 in (6.65 m)
* Disc area: 2,992 ft² (271 m²)
* Empty weight: 23,150 lb (10,500 kg)
* Max takeoff weight: 32,188 lb (14,600 kg)
* Powerplant: 3× Rolls-Royce/Turbomeca RTM322-01 turboshafts, 2,312 shp (1,725 kW) each


* Maximum speed: 167 knots (192 mph, 309 km/h)
* Range: 750 nm (863 mi, 1389 km)
* Service ceiling: ft (m)
* Rate of climb: ft/min (m/s)


* Guns: 2× general purpose machine guns
* Bombs: 2,200 lb (960 kg) of bombs and rockets


* GPS navigation system
* VHF Omnidirectional Radio range (VOR) instrument landing system (ILS)
* Tactical air navigation (TACAN)
* Smiths Industries OMI SEP 20 automatic flight control systemPermission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts.
Virtual Magic is a human knowledge database blog. Text Based On Information From Wikipedia, Under The GNU Free Documentation License. Copyright (c) 2007 Virtual Magic. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

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