Plugging Air-Defence Gaps With Ground-Based AAA

Following a 25-year R & D effort costing 10 billion (US$200 million), series-production of the 25km-range Akash Mk1 extended short range air defence missile system (E-SHORADS) is now being ramped up to meet the increasing demands of both the Indian Air Force (IAF)—its launch customer, and the Indian Army. Now being inducted into service, the Akash Mk1’s air force variant will first be employed for base air defence (thereby replacing the existing S-125M Pechoras), and will later on be deployed for providing ground-based air defence of some 500 vulnerable areas and vulnerable points dotting the country. The first IAF order for two squadrons, valued at 12.21 billion, was placed in May 2009 and comprised 250 missile rounds, 36 wheeled launchers (built by TATA Power’s Strategic Electronics Division), nine battery command centres, nine Rajendra L-band passive phased-array target engagement radars, and nine S-band Rohini 3-D central acquisition radars. The second order from the IAF, valued at 42.79 billion ($925 million) came in November 2009 for an additional two squadrons of the E-SHORADS, which included 750 missile rounds. This was followed in January 2010 by the third order, this time for six squadrons. Prime contractor for the IAF-specific Akash Mk1 E-SHORADS is the Ministry of Defence-owned Bharat Electronics Ltd (BEL), with Hyderabad-based Bharat Dynamics Ltd being the principal sub-contractor. The Indian Army too is expected to soon place an order for up to nine Regiments of Akash Mk1, valued at 125 billion ($2.8 billion), approval for which was obtained in June 2010 from the MoD’s the Defence Acquisitions Council (DAC). The Union Cabinet Committee on National Security on March 17 cleared the induction of an initial two Akash Mk1 Regiments valued at 14.18 billion, each with six Batteries.

When inducted into service by the Army, the Akash Mk1 will replace the existing 27-year-old NIIP 2K12 Kub/Kvadrat medium-range surface-to-air missile (MR-SAM) systems. The Army-specific variant of the Akash Mk1’s missile launcher and the Rajendra PESA radar will all make use of the hull of a T-72M main battle tank in order to achieve superior cross-country mobility. Akash Mk1’s beam-riding SACLOS-guided missile round has a launch weight of 720kg, length of 5.8 metres, and a diameter of 35cm. It can engage aircraft flying 25km away and at altitudes up to 18km. The Rajendra radar can detect 100 targets and track 64 of them, while simultaneously engaging eight of them at the same time. A typical Akash Mk1 Regiment can provide air defence missile coverage of 2,000 square km. The fully-automated Akash Mk1 has an 88% kill probability within a specified kill zone and has even intercepted a target with a 0.02 square-metre radar cross-section (a fighter has a 2 square-metre RCS. The Defence R & D Organisation (DRDO) is now developing the Akash’s Mk2 variant, which will commence its flight-test regime next year. Designed as a MR-SAM, Akash Mk2 will also have faster reaction time and a range of 37km.

Running in parallel are efforts by both the IAF and the Army to replace their existing inventories of OSA-AKM and ZRK-BD Strella-10M SHORADS with RAFAEL of Israel’s Spyder-SR system. The IAF refers to the Spyder-SR as a low-level quick-reaction missile (LLQRM), while the Army calls it a quick-reaction surface-to-air missile (QR-SAM). The MoD’s DAC approved the IAF’s requirement in July 2008, and a $293 million contract for the supply of an initial 18 launchers (making up one squadron) was signed in December 2008. Deliveries began early last month and will be concluded by August 2012. The Army received the green light to procure an initial four regiments of the Spyder-SR in August 2009, and the $900 million contract was inked later that year. The Spyder-SR is the culmination of joint R & D efforts undertaken by RAFAEL and Israel Aerospace Industries (IAI). It is a short-range (15km range), low-level (from 20 metres through to 9,000 metres altitude) integrated, all-weather air-defence system that makes use of the ground-launched Python 5 imaging infra-red guided and Derby radar-guided missiles, which complement each other in their target detection, tracking and pursuit profile . Both missiles are equipped with lock-on before launch (LOBL) and lock-on after launch (LOAL) modes for faster response time and improved engagement flexibility. A Spyder-SR battery includes up to six missile launch vehicles (each equipped with four missile launchers), missile reloaders and a command-and-control Unit that also accommodates the IAI/ELTA Systems-built EL/M-2106NG ATAR 3-D surveillance radar and two operating consoles. The radar can simultaneously track and engage up to 60 targets at a range beyond 35km (depending on the terrain). The command-and-control unit interfaces with the missile launch vehicles via wireless data-link (for up to as distance of 100km) to enable optimal unit dispersion for effective area coverage, mutual protection and survivability. The system's high cross-country mobility offers quick deployment and operational agility. The Spyder-SR also has VHF/HF communications networks for internal squadron-level communication and to upper-tier commands. Once the operator decides to launch a missile, an automatic procedure begins. The command-and-control centre assigns the target to the appropriate launch vehicle and the selected missile will start to search for the target. If the target is within acquisition range the missile will be launched in LOBL mode. If the target is beyond seeker acquisition range the missile will be launched in LOAL mode. The seeker searches for the target and when it acquires the target it begins the terminal homing phase. Both LOAL and LOBL modes are available for the Derby and Python 5. Destruction of the target is achieved either by the warhead blasting upon impact or by proximity fuze.

Also underway are efforts to upgrade and enhance the firepower of the Army’s Corps of Air Defence Artillery by upgrading the fire-control system of 48 ZSU-23-4 Schilka self-propelled air-defence guns (this work being done by BEL teamed up with IAI/ELTA). Once this is achieved, the Schilkas will complement the thirty-six 2S6 Tunguska-M1 gun/missile-equipped self-propelled air-defence guns, 12 of which were acquired in 1993, followed by 24 more worth $400 million in 2006. At the same time, both the Army and IAF have zeroed in on the Rheinmetall Defence-built Skyranger 35mm gun, which can be mounted on lightweight wheeled or tracked armored vehicles. For the IAF, the Skyranger turret will be mounted on a TATA Motors-built 8 x 8 high-mobility vehicle, while the Army variant will comprise the Skyranger turret being integrated with the hull of a BMP-2 infantry combat vehicle. The unmanned turret comes equipped with a 35mm revolver gun, which has a dual feeding system to give the operator the choice of two types of ammunition. This air-defence system is optimised to fire AHEAD (advanced hit efficiency and destruction) self-programming ammunition, which release a cloud of sub-projectiles just ahead of the target, thereby greatly increasing the probability of a kill. A typical engagement sequence consists of 24 rounds with 4km effective range. The Skyranger is also effective against ground targets and can be used as a direct fire-support weapon. For this, use is made of frangible armour-piercing discarding sabot (FAPDS) rounds with an effective range of 5km at a firing rate of 1,000 rounds per minute. It is also capable of firing mini-bursts or single shots. A total of 220 rounds are carried within the turret for the gun. The turret also has an optronic tracking sensor suite that includes an infra-red camera, TV camera, and laser rangefinder. Other components of the Skyranger include a command post vehicle fitted with a reconnaissance radar and command-and-control system, which provides battle management capabilities. Up to 2,000 units of the Skyranger will be acquired by both the Army and IAF.—Prasun K. Sengupta