Armaments used in helicopters can be broadly classified into three categories, namely rapid firing automatic machine guns, rocket projectiles and guided missiles

The range of armament employed on the helicopter since its emergence as a combat platform whether as an armed helicopter or an attack helicopter can be broadly classified into three categories, namely rapid firing automatic machine guns, rocket projectiles and guided missiles. Over the years, all three have continuously evolved turning the relatively slow moving, docile machine into a formidable combat platform. Despite the advancements in accuracy and lethality of air-to-surface guided weapons, of varying calibre, the machine gun still retains its importance and preferred against a variety of targets such as personnel, soft skin vehicles as also thinly protected armoured fighting vehicles.

Machine Guns: Light & Heavy

The 7.62mm calibre, six-barrel M134 light machine gun was developed in the 1960s by General Electric in response to the requirements of the US Army for a weapon with an extremely high rate of fire for defence suppression in the tactical battle area. On account of overheating problems, the rate of fire in terms of rounds delivered every minute had to be reduced from 7,000 to 4,000. During the last nearly five decades, the M134 has undergone a process of evolution, the thrust of the changes being higher levels of reliability though at a lower rate of fire. Garwood, an Arizona-based company, now offers a stainless steel gun with titanium components and chrome-lined barrels. With an in-built facility to select the rate of fire between 3,000 and 4,000 rounds per minute, the gun is designated as the M134G and is employed on the Bell UH-I, Sikorsky UH-60 series and the Boeing MH-6 Little Bird.

In the heavy category were machine guns of 12.7mm or 0.5-inch calibre such as the single-barrel pod mounted FN Herstal M3/Gau-21 employed on the AgustaWestland AW101 and the Bell OH-58D. It has a rate of fire of 1,025 rounds per minute. There is also the triple barrel 12.7mm Gau-19/A with a rate of fire of 1,000 or 2,000 rounds per minute from General Dynamics Armament and Technical Products used on HH/MH-60G helicopters. The 20mm threebarrel M197 cannon also from General Dynamics has been de-rated to fire 650 rounds per minute for mounting in the chin turret on the Marine Corps Bell AH-1W/Z and on the AgustaWestland A129CBT. The higher calibre single-barrel 30mm M230 Chain Gun developed by Alliant Techsystems (ATK) is mounted externally on the Boeing AH-64 Apache. With a capacity of 1,200 rounds, the M230 fires 625 rounds per minute.

With the evolution of the machine gun came the realisation that for helicopter mounted machine guns, very high rates of fire were neither required nor tenable on account of technical limitations and that small calibre ammunition is equally effective. Also, on the heavier machine guns or cannons, the rate of fire being still lower, a singlebarrel option served the purpose equally well.

Rockets

The earliest rockets to be fired from helicopters were unguided and provided an effective option for strike against high value or fortified ground targets. The popular ones amongst these were the 68mm Sneb from Thales/TDA armaments, the 70-mm Hydra-70 from General Dynamics and the CRV7 series from Magellan/Bristol Aerospace. The accuracy and effectiveness of unguided rockets was later substantially enhanced through add-on laser guidance kits that help the rocket home on to the intended target. Such conversion kits available today include the direct attack guided rocket (DAGR) from Lockheed Martin, the advanced precision kill weapon system from BAE the Elbit Star. TDA armaments is meanwhile working on a laser-guided Sneb 68mm under the designation Syrocot. Laser homing kits not only provide a much higher level of accuracy but also a low-cost option. In collaboration with Emirates Advanced Investments, Raytheon is developing the Talon for the Middle East market. Trials of the Talon have been carried out on Boeing Apache AH-64D and Bell OH-58D. Equipped with the Raytheon laser seeker head, subsequent batches of the weapon system will be manufactured in the UAE.