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Aerial pick-ups; the ten tonners: offering an attractive combination of usefulness and affordability, utility helicopters of around ten tonnes are the aviation equivalent of the pick-up truck. Such aircraft are operated in large numbers, and several outstanding designs are competing for new and replacement orders.

The utility helicopter came of age in the late 1960s when the US Army's in-theatre Bell UH-1D/H 'Huey' fleet amounted to approximately 2400 of the 4000 rotary-wing aircraft in Vietnam. The short-body UH-1B/C gunship added around 1200 to the deployed total.

Between 1962 and 1964 the Huey (originally the HU-1A Iroquois) had replaced the Vertol H-21 'Flying Banana' as the standard US Army troop transport. Bell's relatively simple, easily transported two-blade helicopter made possible the service's new 'airmobile' operations, involving up to 250 aircraft in a single force-insertion. This form of warfare was developed to overcome the road transport problems (delays, mines and ambushes) that had defeated pre-1954 French Army efforts to control the countryside of what was then Indo-China.

Although they failed to stem the Communist advance, US Army helicopter operations in Vietnam were sustained from 1962 to 1975 and were conducted on a massive scale, involving the transport of up to 20,000 men and 1600 tonnes of materiel in a single week. No less than 22,000 army helicopter pilots flew in southeast Asia.

Powered by a single 1045-kW Honeywell T53, the UH-1H was designed to accommodate 14 troops or six stretcher cases and has a maximum take-off weight of 4300 kg. The last of over 16,000 Hueys was delivered in 1976, but it is estimated that over 5000 are still in use worldwide. Although most US Army Hueys have been replaced, the service still operates around 150 UH-1Hs and is thought to have over 200 in storage.

Operations in southeast Asia demonstrated that, when fitted with basic defensive armament, a utility helicopter needs a great deal more power than the Huey if it is required to lift a section of troops from hot/high sites. For the US Army the answer was the 7700-kg Sikorsky UH-60A, discussed later in this report.

The US Air Force and Marine Corps adopted the 5080-kg Bell UH-1N powered by 1342-kW Pratt & Whitney Canada PT6T-3 Twin-Pac engines. The US Air Force has 62 UH-1Ns and the US Marine Corps a further 106.

The US Marine Corps originally planned to have 100 UH-1Ns remanufactured to UH-1Y Venom standard, with two 1342-kW General Electric T700-GE-401C engines and four-blade composite rotors. This gave a gross weight of 8390 kg and increased payload by 125%. Maximum cruise speed is raised from 204 to 274 km/hr. Other improvements include the Thales Top Owl helmet-mounted sight/ display, an NVG-compatible glass cockpit and a crashworthy fuel system.

The UH-1Y first flew in December 2001 and the first production aircraft was rolled out in September 2006. On current plans, since remanufacturing the UH-1N to UH-1Y standard means that the aircraft is removed from service for two years, only the first ten will be upgraded from UH-1Ns and the rest will be new-built. Initial operational capability (IOC) is scheduled for September 2008, and the last delivery for the US Marine Corps is due in 2018. Aside from transporting personnel and supplies, the service plans to use the UH-1Y for armed escort, offensive air support, airborne command and control, search-and-rescue (Sar) and casualty evacuation duties.

Other Huey upgrades are available, but in comparison with the UH-1Y they represent relatively low-cost, modest improvements.

The US Marine Corps' so-called 'H-1 Helicopter Upgrades Program', which includes modifying the AH-1W Super-Cobra to AH-1Z Viper standard, may well eventuate as an all-new-build effort. The UH-1Y and AH-1Z both represent a massive jump from the earlier five-tonne to the eight-tonne category.

Marginally Medium

To digress briefly, a number of new designs are aimed at filling the resulting sub-eight-tonne gap in utility transports, including the 6.5-tonne Kamov Ka-60, the 'seven-to-eight-tonne' Agusta Westland AW149 and the Eurocopter/AVIC-II EC175 or Z-15.

The Ka-60 appears to have been progressing at a glacial pace since its first flight in late 1998, but there has recently been a report that production is to begin at the Ulan-Ude plant. Rosoboronexport still lists the aircraft as having 970-kW Rybinsk RD-600V engines, but it is believed that only two of these engines were built and that work on the RD-600V has now stopped. Efforts to promote a Ka-62R version with Western engines (Rolls-Royce Turbomeca RTM322s) have led nowhere. The Ka-60 (and civil Ka-62) will now be powered by the new 1120-kW Klimov VK-1500Vs.

The VK-1500V has an emergency rating (one engine inoperative) of 1415 kW, and a design service life of 12,000 hours. It is to be manufactured in two versions: one with the power off-take rearwards for Mi-8 upgrades and the other with a forward off-take for the Ka-60/62. Reports that it will be developed in cooperation with Motor Sich of the Ukraine are incorrect.

The Agusta Westland AW.149 is a larger military derivative of the 6.4-tonne AW.139, to be powered by unspecified engines in the 1500-kW class. Originally described as a 6.8-tonne aircraft, the AW.149 has evidently grown as more powerful engines became available. With so much power it could easily grow to nine tonnes.

Each of the new projects in this sub-eight-tonne class is clearly positioned to avoid competing with the next higher in the company's project range, such as the 10.6-tonne NH90 and 11.0-tonne EC725.

The Eurocopter/AVIC-II EC175 designation implies a gross weight of around seven tonnes, but a range of << 6.5 to 10.0 tonnes >> was quoted in 2005 by Eurocopter's Fabrice Bregier (more recently CEO of Airbus). Following an agreement in late 2005, each partner is to invest 300 million [euro] in the project, which is due to fly in 2009 and enter production two years later. The EC175 begins life as a civil helicopter, but it would not be surprising if China's Z-15 version also replaces the five-tonne military Z-9 (Dauphin 2).

The EC175 appears most likely to clash with the seven- to eight-tonne Korean Utility Helicopter (KUH), in which Eurocopter is working as consultant for Korea Aerospace Industries (KAI) in the Korean Helicopter Program development phase. The KUH is due to fly in September 2009 with series production to start at the end of 2011.

A joint venture is expected to be formed later to manufacture the 245 KUHs required by the South Korean Army. General Electric, assisted by Samsung Techwin, is developing the T700GE-701K engine selected for the KUH, based on the 1270-kW -701C used in South Korea's UH-60Ps. The -701K is the first of the T700 series to have a rearward power-offtake.

The classic Eurocopter medium utility helicopter is the 9000-kg AS532 AL Cougar, powered by two 1400-kW Turbomeca Makila 1A1 engines. A stretched version of the AS532 AC, it can accommodate up to 25 troops and can be heavily armed, with rockets and forward/side-firing cannon. Recent sales have included an order for twelve of these aircraft for the Bulgarian Air Force, with deliveries beginning in August 2006. Eight of the Bulgarian Cougars are to be employed as tactical transports and four as combat search and rescue aircraft. More than 700 of the Super Puma/Cougar family have been sold to 90 customers in 48 countries.

The latest member of the Cougar family is the 11,000-kg EC725, with 1800-kW Makila 2A engines, a glass cockpit and a five-blade main rotor using technology from the NH90. It has an endurance of up to five hours, which can be roughly doubled by in-flight refuelling. The EC725 can accommodate 29 troops or up to twelve stretcher cases and can carry 5000 kg as a sling load. It first flew in November 2000 and deliveries began in 2004.

The series was launched with an order for six aircraft to fulfil the combat Sar (Csar) mission for the French Air Force, followed by a contract for eight aircraft for the French Army Air Corps, the Alat, to equip the service's special operations detachment (Daos). Trials of the Air Force 'Resco' version have included deck operations from the French Navy's Charles de Gaulle aircraft carrier and Courbet frigate, to ensure suitability for ship-based Csar and anti-terrorism duties.

The EC725 Resco was declared operational in May 2006 and two months later three self-deployed to RAF Akrotiri in Cyprus to rescue French nationals from Lebanon under 'Operation Baliste'. In the face of Israeli strikes around one thousand people were evacuated in the course of 93 sorties.

Europe's 10,600-kg NH Industries NH90 is being built in two basic forms: the TTH tactical transport and the navalised NFH. The company is jointly owned by Eurocopter (62.5%), AgustaWestland (32%) and the Netherlands' Stork Aerospace (5.5%).

The NH90 has a hexagonal-shaped, all-composite, corrosion-free airframe with fly-by-wire controls. It first flew in 1995, and in 2000 the first production contract was signed for a total of 253 NH90s plus 54 options for France, Germany, Italy, the Netherlands and Portugal.

In 2001 Finland, Norway and Sweden announced the NH90 as the winner of their tripartite Nordic Helicopter competition, adding orders for a further 52 plus 17 (recently reduced to seven) options. The Swedish Army version has a cabin raised by 24 cm to provide greater headroom. In August 2003, Greece became the ninth customer with 20 plus 14 options. In July 2004 Oman signed for 20.

In June 2005 Australia contracted for twelve MRH90s, which are a multi service marinised version of the TTH, and in June 2006 added 34 more. Of the total, 40 will be operated by the Australian Army and six by the RAN. New Zealand ordered nine in July 2006 and at the end of the year Spain authorised the purchase of 45. Assuming that this and Belgium's planned procurement of ten TFHs are completed, this will bring the firm total to 455 NH90s for 14 customers, with options on a further 76 units.

With the initial assembly lines in France, Germany and Italy now augmented by others in Finland, Australia and Spain, and 25 different NH90 variants, there have inevitably been delays. However, the TTH was cleared for service in March 2006, and the first deliveries (three aircraft to the German Army) took place later in the year. Deliveries to Greece, Finland and Sweden will begin during 2007, with 38 due to be handed over by the end of the year. The NFH is scheduled for certification in 2008 and the annual production rate will rise to 80 units between 2009 and 2011.

Further sales are anticipated to some of the launch customers. Reports indicate that the consortium has submitted a proposal for 30 NFHs to Germany (which has so far ordered TTHs), and that France (which has ordered only NFHs) is expected to invite proposals for 34 helicopters in the TTH class, with options on a further 34.

Huey Replacement

As indicated earlier, the US Army's 4300-kg UH-1H was largely replaced by the 7700-kg Sikorsky UH-60A Black Hawk, powered by two 1200-kW General Electric T700-GE-700 engines. The UH-60A first flew in 1974 and entered service in 1979. Over 2800 examples of Sikorsky's S-70/H-60 family have been built.

In 1989 production switched to the 10,000-kg UH-60L, powered by 1400-kW T700-GE-701Cs. Due to the increased weight of the 'uparmoured' Hummer, the UH-60L has been cleared to an overload take-off weight of 10,660 kg with a 4080 kg sling load. Plans call for the UH-60L to be equipped with two Lockheed Martin systems to reduce vulnerability to RPG attacks: a Hostile Fire Indicator that senses muzzle flashes and a Visual Acquisition Disruptor based on a dazzling laser. Saudi Arabia is expected to buy 24 UH-60Ls.

In 2006 Sikorsky announced plans to produce a more affordable 'International Black Hawk' overseas, deliveries of which are due to start in 2010. The company subsequently revealed the intention to buy PZL-Mielec from the Polish government.

The latest version for the US Army is the 10,000-kg UH-60M, powered by 1490-kW T700-GE-701Ds and equipped with new wide-chord blades and a Rockwell Collins glass cockpit. The first delivery took place in July 2006 and it is expected that at least 1200 new-build UH-60Ms will be produced. Anticipated export sales include 26 to the United Arab Emirates and nine to Bahrain.

In 2006 Sikorsky announced development of an armed 'Battlehawk' version, available either as a new-build aircraft or as a retrofit kit. The company has separately teamed with Elbit Systems and Rafael in proposing to Israel a specifically equipped and armed UH-60, following the latter's cut in orders for the Boeing AH-64D attack helicopter.

The new Sikorsky S-92, powered by two 1880-kW General Electric CT7-8A engines, has sold only slowly in civil form, and the 12,837-kg military MH-92 Superhawk has taken years to launch. However, in 2004 the Canadian Forces ordered 28 under the designation CH-148 Cyclone and this may encourage further purchases.

Russian Rotors

Russian helicopter facilities are now being consolidated under Oberonprom, which will merge the Kamov and Mil design bureaus, together with the Kazan Helicopters, Rostvertol and Ulan-Ude Aviation manufacturing plants.

Kamov's distinctive co-axial, contra-rotating rotors have a smaller diameter than the single rotor of a conventional helicopter in the same weight category. This approach also eliminates the tail rotor, which has historically been the cause of many accidents. The Kamov series has been built in

many naval (Ka-27/29/31) and civil (Ka-26/32) forms, but has had less success in sales to air forces. The 11,000-kg Ka-29 combat transport helicopter can accommodate 16 armed troops and has an overload take-off weight of 12,600 kg with a 4000 kg sling load. It is powered by 1640-kW Klimov TV3-117VMA engines.

Equipped with the same engines the conventional Mil Mi-17 has been far more successful, and continues to sell. If the earlier Mi-8 series (with less powerful engines) is included, over 11,000 have been produced.

Rosoboronexport offers two versions: the Kazan-built Mi-17-1V, of which 80 have recently been ordered by India, and the heavily armed Ulan Ude-built Mi-171Sh, of which ten have been ordered by Croatia and 18 are expected to be purchased by Ecuador.

A third version, marketed directly by Kazan, is the Mi-17V-5, which has a hydraulically powered rear ramp for loading vehicles. Since the ramp can be left open in flight, it allows the carriage of long loads and the dropping of paratroops. For ferry flights, Mi-17V-5 can carry four 915-litre tanks in the cabin, increasing range to 1600 km. Recent sales include five to Chile and 20 to Venezuela.

Each helicopter series appears to be replaced by something heavier, and the 11- to 13-tonne Mi-8/17 family is to be superseded by the 15,600-kg Mi-38. Now being developed by Kazan Helicopters, the Mi-38 first flew in 2003, powered by 2050-kW Pratt & Whitney Canada PW127T/S engines. Production aircraft will be powered by two 2090-kW Klimov TV7-117V/VMs and deliveries will begin in 2008/2009.

In a similar weight category, the 14,600-kg Agusta Westland EH101 seen in the title photo is powered by three engines: 1670-kW Rolls-Royce Turbome ca RTM322s or 1490-kW General Electric CT7-6As. The current order total stands at 146 units, including 44 for Britain's Royal Navy and 22 for the Royal Air Force, 20 for the Italian Navy, 14 for Denmark, 12 for Portugal and 15 for Canada, designated CH-149 Cormorants. Norway currently appears likely to buy the longer-range EH101 in place of the previously optioned follow-on batch of ten NH90s. Kawasaki is building 16 as KHI-03s. Lockheed Martin is prime contractor for the 26 VH-71As (formerly US101s) for the US Navy-funded presidential helicopter squadron, which are to have improved (Berp IV) blades and 1884-kW CT7-8E engines.
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Title Annotation:Rotary-wing
Author:Braybrook, Roy
Publication:Armada International
Date:Jun 1, 2007
Words:2582
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