Leonardo (AgustaWestland) AW101 / EH Industries EH101 Merlin Medium Lift / Multirole Helicopter
The massive AgustaWestland Merlin helicopter is powered by no fewer than three turboshaft engines to achieve the desired performance for military and civilian causes.
Authored By Staff Writer; Content ©www.MilitaryFactory.com
The AgustaWestland AW101 "Merlin" (formerly the EH Industries EH101 Merlin) is a medium-lift, multi-purpose, multi-role helicopter developed as a joint venture by the British and Italians. To date, sales have increased and its battlefield reach has broadened considerably since development began in the 1980s. The AW101 is a large helicopter system driven by no fewer than three turboshaft engines and the airframe can support a myriad of military- and civilian-minded requirements to include general passenger transport, maritime defense, anti-submarine warfare (ASW), airborne early warning (AEW), search and rescue (SAR), amphibious support, disaster relief and medical evacuations. Over 140 of the type have been produced as of this writing.
By the late 1970s, the world was still embroiled in its "Cold War" arms race. Another war waging across the European battlefields remained an all too real possibility and, undoubtedly, a plethora of military weaponry would be called into play should the Cold War ever go "hot". Key to the success of NATO in the region would be control of the surrounding waters and, as such, ship-based rotary-wing systems would prove of great value. The British and Italian navies found themselves looking for a more modern anti-ship/anti-submarine option to replace their aging American Sikorsky H-3 Sea King platforms (these being produced locally by Westland and Agusta in their respective countries). While the British had already committed to the development of the proposed Westland WG.34, no prototype was constructed before a joint development initiative was struck concerning Westland and Agusta to produce a common end-product as a cost-effective solution. To compliment the agreement, "EH Industries" (European Helicopter Industries) was set up in London in 1980 as a 50/50 partnership. Each participating nation could then receive the same helicopter product at cost, differing only slightly in their final delivery presentation to suit their individual navy requirements.
To evolve the product further, the helicopter was then envisioned to compete on the global market against the Sikosrky UH-60 Blackhawk medium-lift helicopters which had already entered service in 1979. The AgustaWestland helicopter would be designated as the "AW101" and, in 1984, formal agreements between Great Britain and Italy were secured and a mock up was showcased the following year at the Paris Air Show. The first prototype (PP1) went airborne on October 9th, 1987 and proved the large helicopter design viable. The program evolved to include PP2 through PP9, each developed to achieve specific program goals. The British made use of the PP1 testbed while the Italians worked the design through their PP2, this achieving first flight on November 26th, 1987. For the British, the engine of choice became the Rolls-Royce Turbomeca RTM332 series turboshaft while the Italians elected for the General Electric CT7-6 series, the latter produced locally under license through Alfa Romeo Avio and Fiat. Initially, a rear loading ramp was only an Italian military requirement but this was eventually taken up by the British military as well. The PP3 was the civilian-minded prototype and first flew on September 30th, 1988. PP4 and PP5 (first flights on June 15th, 1989 and October 24th, 1989 respectively) were both Westland products, the latter achieving a shipborne landing in 1991. Agusta delivered the PP6 to which first flight was recorded on April 26th 1989 and this prototype made its first shipborne landing in 1991 as well. Westland claimed the PP8 prototype whilst Agusta finalized the PP9 prototype.
All appeared well for the joint helicopter endeavor until the end of the Cold War in 1991. This global shift forced all competing frontline militaries and their governing politicians to rethink spending efforts in a new world devoid of an arms race. The Canadians, who initially held interest in the new EH Industries product, abandoned thoughts of procurement in 1993 after a new government was elected. Steep financial penalties resulted in the cancellation and a new helicopter competition emerged that, once again, ended with the selection of the EH101 in 1997. Despite the setback, Britain and Italy were forced to press on and make good on their expensive venture, ultimately completing development and securing quantitative production orders for their respective navies. These orders were formally placed in 1995 with deliveries beginning in 1997. In 2000, Agusta and Westland were formally merged to become the Anglo-Italian concern of "AgustaWestland" and all previous product designations still in production were therefore updated to the well known "AW" designation. With this merger, the EH Industries product banner was no longer needed and dropped from use soon after. In June of 2007, the EH101 was officially being designated as the "AW101". The British went on to know the helicopter as the "Merlin".
Much care was taken into the design arrangement and appearance of the Merlin, generating a well-contoured system with the cockpit fitted at the extreme forward end of the tubular fuselage with the cabin just aft. The cockpit is well- glazed with excellent vision to the front, above, below and to the sides for both pilot positions with entry accomplished via two hinged automobile-style doors for each person. Cockpit controls in the Merlin are redundant though only require operation by a single pilot. The cabin area is attached to the cargo hold and is dotted with rounded rectangular windows for viewing out of the aircraft. There are blister-type viewing ports further aft to assist in loading/unloading. The cargo hold is to the rear under the tapered empennage. The powerplants are all fitted into streamlined compartments atop the cabin/cargo area and drive a tail rotor via a long-running shaft within the tail boom assembly. The tail boom is completed with a pair of low-set horizontal tail planes and a single vertical tail fin and its specifically designed to be tapered from the ground to allow access to the rear fuselage powered cargo door. The five-bladed rotor mast sits close to the fuselage roof and sports distinct blade tips designed for maximum efficiency when cutting through the air. These are known as BERP from the Westland/RAE "British Experimental Rotor Program". Rotor diameter is 61 feet. The engine nacelles protrude from the sides of the aircraft roof. The tail rotor is a similar assembly though naturally smaller in overall dimension, four-bladed and offset to the portside of the aircraft to counter the torque spin of the main rotor assembly. The main and tail rotors can be folded for ship-board storage. The undercarriage is wholly retractable and consists of a pair of single wheeled main landing gear legs and a twin-wheeled nose landing gear leg. The main legs retract into side sponsons attached to the fuselage (aft of amidships in the design) while the nose landing gear retracts under the cockpit floor. Merlin construction incorporates Kevlar armor along the sides, underside and cockpit framing as well as aluminum-lithium alloy throughout. The main rotor blades are made out of composite materials for lighter overall weight and efficiency (including noise reduction). Beyond its standard crew of four (two pilots and two specialists), the Merlin can house 45 standing infantrymen (assault transport, 24 seated infantry (if installed with cabin seating) or 16 medical litters with room for applicable medical crew (MEDEVAC role). in lieu of cabin personnel, the Merlin is completely capable of hauling cargo pallets in the hold or through an underslung function under the fuselage.
The Merlin can be outfitted with various avionics suites to suite operator requirements. This includes both land-based and maritime types that aid in navigation, communications, automated flight and landing. Additionally, radar systems are equally modular in the Merlin design and can consist of surveillance, search and weather avoidance radar variations. A radar warning receiver (RWR) alerts the crew of inbound threats including homing missiles. There is an integrated Direction Infrared Countermeasures suite with automatically dispensing chaff and flare launchers. Navigation is through GPS. Night-vision goggles provide pilot sighting in the dark and is further aided by the modular turret system that can accept Forward-Looking Infrared (FLIR).
The Merlin series can be left unarmed but its standard armament is a self-defensive network of up to three 7.62mm general purpose machine guns. One machine gun can be fitted to the powered loading ramp at the rear to which the ramp remains lowered in flight. This position can engage any ground-based entities engaging the Merlin itself or provide cover fire for infantry entering or exiting the aircraft. Each fuselage side can sport machine guns on pintle mounts for similar defense. More offensive military-minded roles of the Merlin can see wingstubs fitted for the mounting of unguided rocket pods and machine gun pods. For maritime defense, some navies have outfitted their Merlins with up to four homing torpedoes, anti-submarine depth charges and anti-ship missiles. Collectively, these weapons serve to counter threats posed by both surface and underwater enemies as needed. External fuel tanks can be installed to the aircraft for increased operational ranged while the Merlin is also designed to accept in-flight refueling from a lead aircraft.
The British Merlin is fitted with no fewer than three large Rolls-Royce Turbomeca RTM322-01 series turboshaft engines each developing up to 2,312 shaft horsepower. All told, this supplies the basic airframe with a top speed of 192 miles per hour, an operational range out to 863 miles and a service ceiling of up to 15,000 feet. Rate of climb is listed at 2,000 feet per minute. Her general empty weight is 23,150lbs with a maximum take-off weight (MTOW) of 31,200lbs.
Global operational use of the Merlin series has grown since the type's inception and today include Algeria, Canada, Denmark, India, Indonesia, Italy, Japan, Portugal and the United Kingdom. The Algerian Navy is expected to take delivery of the type soon. The Canadian model is designated as the CH-149 (AW320) Cormorant. The Royal Danish Air Force operates Merlins with their Eskadrille 722 while India has ordered the AW101 as a VIP transport within the IAF. Similarly, the Indonesian Air Force has placed a quantitative order for a dozen airframes. The Italian Navy stocks its 1st and 3rd flight groups with Merlins. Japan makes use of theAW101 in both military and civilian-minded roles (law enforcement). Portugal has set up one squadron of Merlins under the Squadron 751 Puma name. The British Royal Navy began use of the Merlin through its 700M Naval Air Squadron flight group charged with evaluating the platform from 2000 to 2008. Since then, the Merlin has seen considerable use in the 814, 820, 824 and 829 Naval Air Squadrons. The British Royal Air Force is another operator of the helicopter, stocking the No. 28 and No. 78 Squadrons out of RAF Benson. All British, Portuguese and Danish helicopters are known under the "Merlin" name and the British remain the largest quantitative operator of the type.
There are several listed designations in the Merlin family line and most deal with its particular assignment within its respective military force rather than a drastic change in design or operating scope. Production of the helicopter has been ongoing since the 1990s and notable variants include the Royal Navy Merlin HM1, HM2, HC3 and HC3A. Two VH-71 "Kestrels" are under consideration as US Presidential VIP transport mounts with Lockheed Martin being the primary contractor. The CH-148 Petrel was the initial proposed Canadian military platform on order but later dropped from procurement - remerging as the CH-149 Cormorant.
November 2016: It was announced that the first upgraded AgustaWestland Merlin HC.4 helicopter had achieved a first-flight. Twenty-five in-service Royal Navy Merlin HC.3/HC.3A helicopters are scheduled to be upgraded to the HC.4 standard. These will succeed outgoing Sea King HC.4/HC.4+ aircraft from 2017 onward.
January 2017 - Thales and Leonardo, along with Lockheed Martin, will develop an Airborne Early Warning (AEW) kit for installation on Royal Navy Merlin Mk 2 series helicopters.