Originally conceived as a means of escorting a heliborne assault, the role of the first dedicated attack or gunship helicopters was soon expanded to include CAS, primarily achieved using machine guns, cannon and unguided rockets.
After Vietnam, attention turned to giving the attack helicopter night and all-weather capabilities and the emphasis shifted towards the anti-tank role, using dedicated weapons (often wire-guided missiles) and sophisticated sighting systems. These were often roof- or mast-mounted (though not on most US attack helicopters, which retained nose-mounted sights), allowing the helicopter to sit in cover – hovering behind a tree line or other obstacle with only its sight exposed to the enemy, popping up only to fire its weapons.
Soviet doctrine was slightly different and emphasised the use of larger armed assault helicopters which could carry missile reloads, anti-tank guided missile (ATGM) teams or an infantry squad in their cabins. The emphasis on engaging armoured vehicles, however, was similar.
By the end of the Cold War, a new generation of ATGMs had been developed that gave greater fire-and-forget capability, and new sighting systems, including mast-mounted radar like the APACHE’s Lockheed Martin LONGBOW system, were being developed.
But with the end of the Cold War, the spectre of massed Warsaw Pact tank armies rushing across the North German Plain disappeared, and attack helicopters faced an urgent need to embrace new roles or risk becoming irrelevant.
Fortunately, the attack helicopter has proved to be extremely useful for post-Cold War asymmetric warfare, offering a compelling combination of economy, weapons precision and appropriate capabilities, especially the ability to employ a range of direct fire weapons against static and moving targets. Some attack helicopter weapons, like the AGM-114 HELLFIRE and MBDA BRIMSTONE missiles were, already well suited to this kind of mission, offering relatively confined and precise effects that minimise the likelihood of collateral damage, while also being able to target bunkers and semi-hardened targets. Sophisticated attack helicopters have also proved to be well-suited to the kind of armed ISR missions required in today’s asymmetric and COIN operations. Such helicopters can use their advanced sighting systems to provide night and all-weather imaging.
One Size Does Not Fit All
Though the range of attack helicopters is relatively modest and cruising speeds are low, the helicopter’s ability to be forward deployed close to the ground forces that it supports minimises these disadvantages, and on-station times may be longer than would be the case for more distantly-based fast jets.
Although the Boeing AH-64 APACHE continues to dominate the attack helicopter market, a reduced emphasis on ‘heavy duty’ tank-killing has led to increased opportunities for smaller, lighter, and cheaper armed helicopters, some of which may be superior to the mighty APACHE in certain niche roles. When Bahrain came to select a replacement for its ageing Bell AH-1 COBRAs, the APACHE was eliminated at an early stage, partly on cost grounds, but also because the Royal Bahraini Air Force (RBAF) evaluation team was unhappy with how long it took to preflight and get into the air, believing it was too big and insufficiently agile for operations in urban surroundings. In the end, the RBAF narrowed its choice down to the Bell AH-1Z and the Turkish Aerospace (TAI) T129 ATAK. Both of these are dedicated two-seat attack helicopters, and thus offer a fairly direct alternative to the APACHE.
Dedicated attack helicopters remain extremely useful, but some operators have opted for less specialised but more versatile armed helicopters, which can operate as gunships or can carry troops or special forces troops – sometimes, but not always, at the same time. Such helicopters span an enormous range in terms of size, cost and complexity. At one end of the spectrum are aircraft like the Boeing MH-47G CHINOOK Special Operations helicopter, or the AW101 ‘Surveillance and Intervention’ variant developed to meet Algerian Gendarmerie Nationale requirements, with its ability to carry rocket pods and an EO/FLIR turret. Then there are armed versions of smaller tactical transport helicopters, typified by the S-70i and BATTLEHAWK versions of the UH-60 BLACK HAWK, and armed versions of the Russian Mi-17.
Some examples of a previous generation of dedicated attack helicopters also remain in service, including missile-armed variants of the GAZELLE. There are also some armed versions of smaller twin-engined and larger single-engined helicopters, like the AW109, Bell 407 and Bell 429.
At the opposite end of the spectrum are helicopters in the same broad class as the US Army’s MH-6 LITTLE BIRD, relatively lightly armed but able to carry a small section of soldiers when required. At this lighter end, there is little or no hard demarcation line between attack and armed ISR helicopters, and helicopters tasked with ISR and ISTAR duties increasingly need to be armed, since counter insurgency operations often require the engagement of fleeting targets, requiring every sensor to also be a shooter’if engagement opportunities are to be maximised.
Increasingly, operators are looking for the ability to re-role helicopters to give them attack capabilities when required, but without carrying the weight penalty of weapons pylons, sensors and sighting systems when engaged in routine transport missions. Airbus Helicopters has responded to this demand by developing its HForce system, a platform-agnostic modular weapons system that may be applied to any helicopter in the Airbus range, with the sole exception of the H175. Built around a Rockwell Collins mission computer and Thales SCORPION helmet-mounted sights, the HForce system is compatible with a range of weapons, included podded machine guns, laser-guided rockets and ATGMs.
Initially, HForce is being offered on the H125M, the H145M and the H225M, with Serbia and Hungary selecting the system for their newly acquired H145Ms, and with Singapore’s H225Ms being ‘fitted for’ but not fitted with the system – a configuration known as ‘option zero’.
For light ISR missions, the HForce ‘option one’ uses unguided 68mm rockets and an FN Herstal 12.7mm gun or a Nexter 20mm cannon. ‘Option two’ adds an L3 Wescam MX-15 EO/IR turret, while laser-guided rockets and ATGMs are added with ‘option three’.
But adding weapons capabilities does not turn any rotorcraft into a dedicated attack platform. The attack helicopter designation implies an armoured helicopter with a fully integrated gun, provision for ATGMs, stub wings with weapons hardpoints, and normally with stepped tandem cockpits, usually with the gunner/weapon systems operator occupying the front cockpit and the pilot behind.
From A to Z
Set to remain in production until 2026, and still attracting new customers, the APACHE is the apex predator among attack helicopters, the most capable and most expensive option, but also in service in huge numbers. In its latest AH-64E GUARDIAN form (originally known as the AH-64D Block III), the aircraft has improved digital connectivity, the Joint Tactical Information Distribution System and an L-3 Communications MUM-TX datalink; T700-GE-701D engines with upgraded face gear transmission to allow more power; and new composite rotor blades, which increase cruise speed and rate of climb while also allowing for higher payloads.
The GUARDIAN has enhanced maritime operations capabilities and its updated LONGBOW radar has an improved overwater capability. An AESA radar upgrade is reportedly under consideration. Still armed with an under-nose 30mm M230 Chain Gun (now manufactured by Northrop Grumman, then Orbital ATK), a single-barrel electrically operated automatic cannon, the APACHE can also carry guided and unguided rockets and ATGMs including HELLFIRE and BRIMSTONE. APACHEs serve with or are on order for the US Army, Britain’s Army Air Corps (Westland-built aircraft with more powerful RTM-322 engines), Egypt, Greece, India, Indonesia, Israel, Japan, Kuwait, the Netherlands, Qatar, the Royal Saudi Land Forces and Saudi Arabia National Guard, Singapore, South Korea, Taiwan and the UAE.
The Bell AH-1 COBRA was the first ‘designed from the ground up’ attack helicopter, and the first to use the now familiar tandem seat configuration to minimise frontal cross section. Though the original single-engined version has been replaced by the APACHE in US Army service, relatively large numbers remain in service in Turkey, Bahrain, Jordan, Japan, South Korea, Thailand, Pakistan, the Philippines and Kenya. The twin-engined SUPER COBRA remains in frontline USMC service, and is operational in Turkey, Taiwan and Iran.
The new AH-1Z COBRA VENOM was developed in conjunction with the UH-1Y VENOM (an upgraded UH-1 HUEY) as part of the H-1 upgrade programme for the USMC. About one third of the 189 AH-1Zs being procured will be new-build, the remainder being converted from AH-1Ws. The new variant adds a new Target Sight System (TSS) and features a new composite four-blade main rotor which gives improved performance, greater agility, reduced noise and vibration and improved battle damage tolerance, together with reduced maintenance. Together with a new drivetrain and new tail rotor, the new rotor system also allows for an increased payload. Wingtip stations have therefore been added to the redesigned stub wings, and these can carry an AIM-9 SIDEWINDER or even a LONGBOW radar.
During the protracted development of the Airbus Helicopters (then-Eurocopter) TIGER, the Soviet Union collapsed and the Cold War ended. France and Germany re-framed the TIGER as a multirole attack helicopter, rather than as the ‘pure’ anti-tank machine that had originally been conceived. With this more relevant basis and its modern design, incorporating Europe’s first all-composite helicopter airframe, a four-bladed hingeless main rotor, an advanced glass cockpit, and even some stealth technology, the highly agile TIGER should have been a winner in the export market, as well as at air shows, with its easy handling and its ability to perform looping and negative G manoeuvres. But the aircraft has struggled to find customers, and only Australia and Spain have joined France and Germany in operating the type. The aircraft has experienced a number of reliability and maintainability issues in service, but despite these, the TIGER has seen active service in Afghanistan and Mali. Unusually, the TIGER’s handling pilot usually occupies the front cockpit, with the gunner seated behind. Either crew member can manage the weapon systems or the primary flight controls, and can switch tasks if required.
The Agusta A129 MANGUSTA was Europe’s first indigenous dedicated attack helicopter, and has served with distinction with Italy’s Army Aviation, deploying on UN peacekeeping operations in Macedonia, Angola and Somalia, and deploying on combat operations in Iraq. The up-engined and improved A129 International, or A129I, added a five-bladed main rotor, an M197 three-barrel 20mm cannon, support for HELLFIRE and STINGER missiles, and LHTEC T800 turboshaft engines.
This latter variant forms the basis of the license-built TAI T129 ATAK, which adds some Turkish avionics and weapon systems. TAI has already sold 59 to the Turkish Land Forces, and has options for 32 more, with a further nine for the gendarmerie and an additional 30 now sold to the Pakistan Army.
There are only 11 Denel ROOIVALK attack helicopters in service (a 12th was written off in 2005) – a number that belies the soundness of the design, but which may reflect US and French government pressure on some potential purchasers. The ROOIVALK is based on the Atlas ORYX powerplant and dynamics system – and as such is basically taken from the AS332 SUPER PUMA. This gives the ROOIVALK plenty of power, and hot and high performance is correspondingly good. The aircraft is also phenomenally agile and highly aerobatic by helicopter standards. Designed for African operating conditions, the aircraft requires minimal support and has proven itself to be rugged and reliable in service. There have been suggestions that the production line (closed down in 2007) could be re-opened, but this would require an order for at least 70 aircraft to be economically viable.
The Hindustan Aeronautics (HAL) Light Combat Helicopter (LCH) was developed as an attack helicopter capable of unrestricted operations in high-altitude environments, and intended for use by the Indian Armed Forces as well as for export. The LCH was developed using the engines and dynamics system of the HAL DHRUV, but progress has been slow. Initial operational capability (IOC) was originally expected in 2010, is now scheduled for 2018, but seems unlikely to be achieved. Meanwhile, India has received the first of 28 AH-64E APACHEs, and eventually intends to operate 39 AH-64Es in three squadrons.
With its ability to carry eight soldiers, the Mil Mi-24/25/35 HIND differs from other attack helicopters, and could be viewed as being more of a flying infantry fighting vehicle than a flying tank destroyer, though it packs a heavy punch, carrying rockets, ATGMs and guns of various calibres. Entering service in 1972, the Mi-24 has achieved an impressive combat record, not least in Afghanistan.
The latest Mi-35M variant is still in production and a bewildering array of upgraded variants are in service, with improved sensors and sighting systems and enhanced weapons capabilities. Though rapidly disappearing from Russian and East European service, the HIND has become the gunship helicopter of choice in the developing world. Some 58 nations operate the type, though many of the African operators have fewer than six aircraft, and some have only one or two in service.
Two competing helicopters were developed to replace the Mi-24/25/35 in Russian service – Mil’s own tandem-seat Mi-28A HAVOC and Kamov’s single-seat Ka-50 HOKUM, Though the Ka-50 won the contest and 12 were delivered, in the end Russia decided to procure follow-on night- and all weather-capable derivatives of both types.
The Mil Mi-28N (Mi-28NE for export) adds new sighting systems and a mast-mounted radar, and is of generally conventional configuration, with a five-bladed main rotor and a Delta H tail rotor. Unusually, the Mi-28 incorporates a small, windowless passenger compartment capable of carrying three people, intended to allow the rescue of downed helicopter crews. A Mil Mi-28UB variant with dual controls for training or dual pilot operation is available, and dual controls may be standard on the export version. The Mi-28NE has been exported to Algeria and Iraq, and is on order for Venezuela.
To produce the night- and all weather-capable Ka-52, Kamov added a second crew member, opting for side-by-side seating. The Ka-52, known as the ALLIGATOR, retained the coaxial contra-rotating main rotor design of the Ka-50, and so needed no tail rotor. To avoid major weight increases, the armour and cannon magazine capacity were reduced, though the redesign did have an impact on performance, with a reduced rate of climb and a lower maximum positive load factor. A new, more powerful VK-2500 engine kept performance reductions to a minimum.
A new version, the Ka-52E NILE CROCODILE, was developed for export to Egypt, with an increased takeoff weight, a reinforced and corrosion resistant airframe and a new landing gear. The Egyptian variant has updated avionics and a new cooling system and a new OES-52 optronic system co-developed by Kamov and Sagem. The NILE CROCODILE has an Arbalet-52 dual-band coherent pulse radar and revised defensive systems, including DIRCM. The Ka-52 will equip the two French- built MISTRAL-class amphibious assault ships, originally ordered by Russia but embargoed and sold to Egypt. It is unclear whether Egypt will order further Ka-52s built to the navalised Ka-52K KATRAN standard, or whether some or all of the 46 aircraft already on order will be delivered with similar modifications, which include folding rotor blades, and folding wings as well as a new fire-control radar with additional over-water modes, and compatible with anti-ship missiles.
The Z-10 is not China’s only attack helicopter programme. In service, it is likely to be supported by the smaller, lighter Harbin Z-19 BLACK WHIRLWIND reconnaissance/attack helicopter, which may spawn a dedicated attack variant with millimetre-wave radar and a gun.
An Unclear Future
It is not clear what the distant future holds for the attack helicopter. Some of its roles may one day be performed by unmanned combat air vehicles (UCAVs) or by optionally-manned rotorcraft – though many believe that these will continue to augment attack helicopters (which may control them) rather than replacing them. A new generation of fixed-wing light attack aircraft may take over some tasks from dedicated attack helicopters – especially those with real short takeoff and landing (STOL) and rough field capabilities that allow them to be based further forward. New weapons with greater stand-off range may reduce the need to get ‘up close and personal,’ and may allow more of the attack helicopter’s CAS and COIN role to be undertaken from higher altitudes and greater distances.
Alternatively, new rotorcraft configurations – including compound helicopters and tilt rotors – may revolutionise attack helicopter performance. Experiments are already underway to assess the applicability of new directed energy weapons on attack helicopters, and other developments in weapons promise to make the genre ever more deadly.
New technologies may thus render this class of aircraft even more useful, which would make them harder to replace. But all of this remains uncertain and far in the future. Meanwhile, several of today’s attack helicopter types look set to remain in service for many decades to come.