A wolf in sheep's clothing: although lacking the speed, manoeuvrability and small target area of a dedicated attack helicopter, a utility or light/medium transport helicopter can carry a useful load of weapons and sensors. Its operational flexibility makes it particularly attractive to smaller forces, and its capability may be enhanced by upgrades. (Air Warfare).

The first attack helicopters were produced by arming utility aircraft. Investigations into the offensive use of rotary-wing aircraft can be traced back to 1942, but the first operational employment of armed helicopters occurred in the late 1950s in Algeria, with the French Army's Aerospatiale (now Eurocopter) Alouette equipped with AS 11 missiles. In the following decade the need to suppress enemy ground fire during US Army airmobile operations in South Vietnam led to the arming of some examples of the Bell Model 205 UH-1 Iroquois, better known as the `Huey'. It was only when the high aerodynamic drag of the externally-armed UH-1 was found to make it too slow to effectively escort its troop-carrying counterpart that the concept of a dedicated attack helicopter (in the form of the lighter and more slender AH-1 HueyCobra) came into favour.

Despite the passage of time, both the Alouette and the Huey are still in use. Hindustan Aeronautics is currently upgrading a dozen Indian Army Cheetahs (licence-built Alouette IIs) to the `Lancer' configuration, and the company hopes to similarly upgrade the rest of the service's fleet. The modification allows the aircraft to carry two pods, each housing a 12.7 mm machine gun and three 70 mm rockets. The `Lancer' upgrade is aimed at improving effectiveness in the Coin, close air support and anti-tank roles.

The Bell UH-1B/C gunship played a major role in the Vietnam War, in 1967 forming 30 per cent of the US Army's helicopter fleet in South-East Asia, while UH-1D/Hs transports formed a further 60 per cent. Even the UH-1D/H had a flexibly-mounted machine gun in either door for lateral cover. Recent upgrades for the Huey series have emphasised the use of improved engines, notably re-lifed Honeywell T53s, General Electric T700s, or LHTEC T800s. Pratt & Whitney Canada (P&WC) is promoting the PT6C-67D for the UH-1, and is considering developing a more powerful variant of the PW200 series. The last Huey was delivered in 1976, but the US Army is planning to retain upgraded UH-1s in service until at least 2010. The US Marine Corps is having 100 UH-1Ns brought to UH-1Y standard, with GE T700 engines and four-blade composite rotors. There are estimated to be around 3200 examples of the UH-1 family in service worldwide.

Lightweights

The lightest helicopters to be armed are those developed originally by Hughes Helicopters, then McDonnell Douglas, which was taken over by Boeing in 1996. The latter's light helicopter division was purchased by the Dutch-owned MD Helicopters in 1999. The Defender is an armed version of the OH-6 Cayuse light observation aircraft, based on the MD500/520/530 series. The Nightfox is a Defender variant with flir and provisions for the crew to use night vision goggles.

Defenders were first used operationally by the Israeli Air Force in Lebanon in 1982. The US Army's Special Forces equivalent of the Defender is the AH-6/MH-6 Little Bird (based on the MD530F), which was used in Grenada in 1983 and against Iranian vessels in the Persian Gulf in 1987. Armament options include the Raytheon Stinger air-to-air missile. The Mission-Enhanced Little Bird (Melb) programme gives these aircraft the more powerful Rolls-Royce 250C30R3 engine, a four-blade tail rotor and the six-blade main rotor from the MD600.

The largest of the MD Helicopters family is the twin-engined, eight-passenger MD900 Explorer, a multi-role military version of which was unveiled in 1995 under the name Combat Explorer. MD Helicopters does not appear to be marketing an armed version, but Explorers are being sold to armed forces and paramilitary services.

Just as the US Army's OH-6 provided the basis for the AH-6/MH-6, the service's single-engined Bell OH-58A Kiowa scout helicopter formed the starting-point for the OH-58D Kiowa Warrior, which was equipped with a mast-mounted television camera, thermal imager and laser ranger/designator. It also has a store position on either side, able to accommodate two Hellfire anti-armour missiles, a pod of seven 70 mm Hydra 70 rockets, two Stingers or a 12.7 mm machine gun pod. The OH-58D is used in armed reconnaissance and helicopter escort duties. A somewhat lighter and more simply equipped export aircraft is the Model 406CS Combat Scout, which Saudi Arabia purchased under the designation MH-58D.

The twin-engined Eurocopter BO 105 is in the same weight category as the OH-58D, and is available in military form, having served for many years as the German Army's PAH-1 anti-armour helicopter, armed with the Euromissile Hot anti-tank guided weapon. The latest military version of the BO 105 is the improved CBS-5 or `Super Five', which is produced in both land- and ship-based forms, the latter having a 360-degree search radar.

The Eurocopter AS 550/555 Fennec is marginally heavier than the BO 105, and is manufactured in both single- and twin-engined versions. The AS 550C3 is a single-engined Fennec with provisions for a wide range of axial-mounted weapons and a side-firing cannon. The AS 555AN is a twin-engined Fennec which can mount axial weapons, and the AS 555SN is its torpedo-armed ASW (anti-submarine warfare) equivalent.

The latest of the Eurocopter twin-engined lightweights is the EC 635, which is available with either Turbomeca Arrius 2 BiB or P&WC PW206B2 engines, the corresponding designations being EC 635T1 and 635P1 respectively. This multi-role aircraft can accommodate two pilots and six troops. Portugal has ordered EC 635T1s.

Roughly equivalent in weight to the MD Explorer is the AgustaWestland A109M, which (like the EC 635) is available with Arrius or PW206 engines. The A109M was the winner in the recent South African contest, which led to an order for 30 aircraft, with an option on ten more. The first four or five are being built in Italy, but the remainder are to be assembled by Denel. There are believed to be more than 150 military A109s in service or on order, worldwide.

Representing almost a 50 per cent increase in gross weight over the Al09, the Eurocopter AS 565 Panther is a military equivalent of the Dauphin, and able to accommodate up to ten troops. The only armed version currently on offer appears to be the naval AS 565AB, which can be equipped with anti-ship missiles or anti-submarine torpedoes. Perhaps the best-known export version is the Royal Saudi Navy AS 565SB, with the Thales Agrion radar and Aerospatiale (now MBDA) AS.15TT anti-ship missiles.

The Dauphin/Panther series is in a weight class of its own, being substantially lighter than the Bell UH-1 Huey and the AgustaWestland Lynx family. The British Army has found its Lynx general-purpose series extremely useful, being able to perform utility duties, carry out anti-armour strikes with the Raytheon Tow missile or move Euromissile Milan teams around the battle area. The current Battlefield Lynx is equivalent to the British Army's Lynx AH9 with up-rated Gem engines, but has failed to win export orders.

The Royal Navy's Lynx HMA8 also has up-rated Gems, but the naval Super Lynx is offered for international sales with LHTEC CTS800-4N engines. In this form it has been selected for the Royal Malaysian Navy. This second-generation naval Lynx has a 360-degree radar (BAE Systems Seaspray or Honeywell RDR-1500), and can carry two ASW torpedoes or up to four BAE Systems Sea Skua anti-ship missiles, which were used in the 1982 Falklands conflict and the 1991 Gulf War.

The military version of the Bell/Agusta Aerospace AB139 was designed as a Huey replacement, and is significantly larger than the Lynx and Bell 412, being able to carry up to fifteen troops. It has a number of interesting features, including a five-blade main rotor, a hexagonal fuselage cross section for reduced radar response, two internally mounted lateral machine guns and high-set external stores to optimise their field of fire. The civil prototype first flew last February.

The Kaman SH-2G Super Seasprite is in new-build production for New Zealand, although Australia and Egypt are having their orders fulfilled by rebuilding and upgrading ex-USN SH2Fs. With two General Electric T700 engines, the SH-2G is relatively overpowered, and well able to deal with high ambient temperatures. For attacking ships, the Australian version will use the Kongsberg Penguin, and the New Zealand aircraft will use the Raytheon Maverick. The Egyptian version is dedicated to the ASW role, using Mk 46/50 torpedoes. The SH-2G also has provisions for machine guns to be mounted in both doorways.

The new Kamov Ka-60 Kasatka (Killer Whale) first flew at the end of 1998 and offers the prospect of serious multi-role capability, if Russia can fund series production. It can accommodate ten fully armed troops, and reportedly has provisions for forward-firing weapons. The Ka-60 is an unusual project, in the sense that the conventional single main rotor goes against Kamov's co-axial tradition, and the ducted tail rotor likewise represents innovation. In addition, the Ka-60 is half the weight of the Mil Mi-17, and it is thus difficult to assess what it will replace.

Production of the Aerospatiale (now Eurocopter) AS 330 Puma ended in 1989, by which time 46 countries had received a total of 697. This included a handful assembled in Indonesia and 145 built under licence in Romania. The Romanian Air Force has now contracted for IAR-Brasov, teamed with Elbit Systems, to upgrade an initial batch of 24 to Puma-330 Socat standard, with new avionics, a modernised cockpit and armament provisions, including a 20 mm Giat gun turret.

Middleweights

On the French production line the Puma was followed by the AS 532 Super Puma or Cougar Mk 1. Armed variants are the short-fuselage AS 532AC, which can carry up to 21 troops, the long-fuselage AS 532AL, which accommodates up to 25 and the short naval AS 532SC with a folding tail rotor pylon, deck landing assistance device and provisions for two AM39 Exocet anti-ship missiles or ASW torpedoes. The Cougar Mk 2 combines a further cabin extension (seating up to 29 troops) with uprated engines, improved rotors and a stretched rear fuselage. The armed versions are the AS 532A2 and 532A2+, the latter having a further increase in engine power and a five-blade main rotor.

Although no longer in production, the AgustaWestland Sea King will continue in service for many years, and can be fitted with powerful armament. For example, the Pakistan Navy's shore-based Sea King 45 can carry two AM39 Exocet missiles. The BAE Systems Sea Skua and the long-range Sea Eagle anti-ship missiles have also been test-fired from the Sea King.

The US Navy was relatively late in adding anti-ship guided weapons to its Sikorsky SH-60B Seahawk. However, following experience in the Gulf War (in which the Navy relied on fixed-wing aircraft or Coalition helicopters for anti-ship strikes), the Kongsberg AGM119B Penguin has now been cleared for use on the SH-60B, which also has provisions for Mk 46/50 torpedoes and Hellfire missiles.

The US Army's corresponding UH-60 Black Hawk series, which carries up to 14 troops, has standard provisions for two side-firing 7.62 mm six-barrel GAU-2/B Gatlings or single-barrel 12.7 mm guns. The service's Special Forces have up-gunned their Black Hawks to carry two pintle-mounted 12.7mm GAU-19A three-barrel Gatlings, which can be locked in a forward-firing position for operation by the pilot. Sikorsky's ESSS (external stores support system) provides for up to 4536 kg of external loads, one option being 16 Hellfire missiles. A further 16 rounds can be carried internally. The Black Hawk was proposed as a solution to the Australian Army's armed reconnaissance and fire support requirement (Air 87) under the name `Night Ranger', with Hellfire and Maverick missiles.

Heavyweights

The Kamov Ka-29 may best be described as a ship-based assault helicopter, capable of carrying up to 16 marines in its cabin. Internal armament consists of a nose-mounted, remotely-controlled four-barrel 7.62 mm Gatling. It can be depressed through 31 degrees, turned 30 degrees to the right and 28 degrees to the left. The Ka-29 also has four external mounting points for stores, illustrated at its debut at Hannover's ILA-90 airshow by eight anti-tank guided missiles outboard and two 80 mm rocket pods inboard. It is believed that around 30 Ka-29s are in service with the Russian Navy and that the Ukraine Navy operates a smaller number.

Widely varying figures have been quoted for the Mil Mi-8/17 series, but it has been stated by Alexander Lavrentyev, managing director of Kazan Helicopter, that over 11,000 have been delivered, including 4500 for international sales to more than 70 countries. The series is capable of carrying up to 30 troops.

Although the first Mi-8 had its maiden flight in 1962, there are well over 3000 of the Mi-8/17 series still in use. The Mi-17 differs from the Mi-8 primarily in having more powerful Klimov TV3 engines, replacing TV2s. Later models of Mi-8 could be very heavily armed, with a flexibly-mounted 12.7 mm machine gun in the nose and external hardpoints for six 32-round rocket pods and four anti-tank guided weapons. The Mi-17 introduced the ability to carry the 23 mm UPK-23-250 cannon pod.

The latest version of the M-17 is currently being developed by Kazan and is designated M1-17V5, which features a loading ramp instead of the traditional rear clamshells, a starboard door (which necessitated moving the auxiliary power unit pod above the door), and Dolphin-shaped nose under which are affixed the Stabilised thermal and TV designator pod for the Vikhr missiles. The V5 is expected to undergo trials with the Vikhr by the time these lines are published.

Yet another development is the V7, which will be powered by VK2500 engines. Kazan is currently looking for a new transmission that would enable to better exploit the 2500 horsepower available from the new engines, which would provide 2400 take-off, 1900 continuous and 1700 cruise horsepower ratings. This plus new composite blades should combine in providing out-of-ground-effect hover capabilities, at 11,500 kg take-off weight, of 3700 metres ISA and 3000 metres ISA +20 [degrees] C -- and hover at 4500 metres ISA and 3900 metres ISA +20 [degrees] C in ground effect. The new APU (understood to be fitted to the test V5) enables air-conditioning or heating to be used during the take-off phase, and the use of plug-in hydraulic appliances for durations of up to six hours. Pending the availability of a suitable main gearbox the V7 should be completed by mid-2003.

Recent upgrades for the series have included the Ulan-Ude Mi-8AMT(Sh) with self-sealing tanks, crew armour, 192 chaff/flare cartridges and provisions for 9M114 Shturm anti-tank and 9M39 Igla-V air-to-air guided missiles. Defensive armament includes a rear-mounted PKT machine gun, four pintle-mounted AKMs and two PKTs for lateral protection.

Kazan has developed a rear-loading ramp for the Mi-17MD, which has provisions for night vision goggles, and 9M14 Malyutka-2 anti-tank and Igla-V air-to-air guided missiles. Kazan also worked with Kelowna Flightcraft of British Columbia on the Mi-17KF Kittiwake variant with a glass cockpit and Western avionics.

Earlier this year it was announced that the Russian Ministry of Defence had accepted a proposal by Russkaya Avionika to modernise a small number of Mi-8s to Mi-8MTKO standard, with a glass cockpit, EO/flir/laser turret and night vision goggles. The Mi-8MTKO first flew in January 1999 and has been evaluated in Chechnya.

The Indian Air Force has a requirement to upgrade 80 Mi-8/17s, a task that is being competed by two teams. Hindustan Aeronautics is working with IAI, while Elbit Systems (with its Andor upgrade) is teamed with Kazan and Denel. At the Aero India airshow at Bangalore in February IAI's Lahav division debuted its Peak 17 project with the Rafael NT-D Dandy and NT-S Spike anti-armour guided missiles, and avionic systems based on those for the Kamov Ka-50-2 offered to Turkey. Other divisions of IAI involved in the Peak 17 are Mata (avionic systems and NVG-compatible displays), Tamam (optronic payload and helmet-mounted sights) and Elta Electronics (electronic warfare suite).

In short

* "The first attack helicopters were simply armed utility aircraft"

* "Non-dedicated attack helicopters are inevitably penalised in speed, manoeuvrability and vulnerability"

* "Conversely, they can carry heavier armament and sensor loads, and provide all-round firepower"

* "Above all, they provide multirole capability, and are logically more attractive to smaller services and ..."

* "Are therefore far from being old fashioned and still very much in demand."