The European Aviation Safety Agency (EASA) has recently issued a warning to all national aviation authorities and aircraft operators of enhanced risk to the safety of civilian aircraft from terrorists, while flying over Pakistan. This warning has been issued at the behest of the civil aviation regulator of France, DGAC, that has made it mandatory for French aircraft operators not to fly below an altitude of 24,000 ft in Pakistan. Indian and South East Asian airlines, flying to and from Europe, routinely fly over Pakistan. Danger to the civilian aircraft these days emanates from Shoulder-Fired Missiles (SFMs), now easily available to terrorists. Downing of a passenger aircraft creates a tremendous psychological impact on the travelling public, is debilitating to the aviation industry and confronts the nation owning the aircraft with a serious dilemma. Security has been enhanced considerably at civilian airports in India in the last few years. However, a terrorist armed with SFMs, operating outside the airfield perimeter, can easily target an aircraft that is either landing or taking off. At these times, the plane will be well within the range of SFMs and becomes an easy target.
Man-portable Air Defence Systems (MANPADs) were developed in the 1940s to protect ground forces from enemy aircraft. They have received a great deal of attention in recent years as potential terrorist weapons that might be used against commercial airliners. These missiles, affordable and widely available through a variety of sources, have been used successfully over the past three decades both in military conflicts, as well as by terrorist organisations. A UN Report says that there are more than 5,00,000 such shoulder-fired missiles, popularly called MANPADS, in the world — a big chunk of them in terrorists’ hands.
ANZA is a series of shoulder-fired surface-to-air missiles, produced by Pakistan. Guided by an infra-red seeker, Anza is used for low-level air defence in the military environment and is also used by terrorists against passenger aircraft. There is every possibility of such a light weight, man-portable and inexpensive weapon being made available to Indian terror modules. The man-portable SFMs can be easily assembled in the field without training. In December 2002, it was reported that Indian soldiers of the 24 Rashtriya Rifles found an Anza Mk-I in a militant hideout near the Line of Control in Kupwara, Kashmir. An Anza system had previously been found at a militant hideout in 2001. In 2003-2004, the US Department of Homeland Security decided to equip 7,000 plus fleet of civilian airliners with suitable equipment to provide protection against SFMs. Two companies were tasked to independently carry out research and design such a system. Currently, all airliners of El Al, the national airlines of Israel, are equipped with a system for protection against SFMs. Singapore Airlines has also evinced interest in such a system. Other airlines that operate over terror-affected areas in Africa, West Asia, Europe and Asia, are also evaluating this concept. A more pragmatic solution would be to equip all airliners with a system that would provide protection against SFMs. No weapons will be required onboard the aircraft. The system will only deflect incoming missiles.
While systems to warn against an air-to-air missile attack are employed on military aircraft, the problem is more complex for both civil and military aircraft in the case of an attack by SFMs. The sensor of the warning device would be required to scan the surface of the Earth below the aircraft and ought to be able to distinguish the oncoming SFM from ground clutter. Some firms have developed Ultra Violet (UV) band sensors to detect the missile exhaust plume. Some others claim infra red band is most appropriate. Both sensors have their positive and negative points. It is also possible to detect an SFM by radar return; but the missile being of small size and at close range, it has not been found to be effective. Pulse Doppler Radar is useful to detect radar return against heavy ground clutter, when the sensor is pointing towards the ground. Multiple sensors have to be used to look in different directions and rapid scan capability is a must as time of flight of the missile is short.
As a terrorist may not exactly be positioned in line with the runway and can successfully conceal himself, the sensors would need to scan 360 degrees. The system is vulnerable to false alarms as it can be confused by other heat sources like active chimneys, vehicles, etc. The terrorist aims at an aircraft and fires the missile, an operation that is relatively simple. After launch, the missile takes a few seconds to stabilise and build up speed before its heat-seeking homing device locks on to the aircraft exhaust. Thereafter, the missile moves at supersonic speed. The protective system must respond within this time frame.
Passive counter-measures include dispensing of chaff i.e, aluminum foil or flares to disrupt the guidance system of the missile deflecting it away from the aircraft. Active counter-measures involve firing of high-power solid-state laser beam towards the incoming missile. It is, of course, expensive and such high power solid-state lasers are available from a few sources only. Since the time available is limited, the operation of the defensive system must be totally automated. The pilot should not be required to execute evasive manoeuvres that could endanger the aircraft if carried out while flying at low speed and at a low altitude.
It has been estimated that the cost of fitment of an anti-SFM system on a civilian aircraft would be lower than that for a combat aircraft. The figure is pegged at $1.125 million. Over a complete life cycle of the aircraft, based on average load factor achieved, the cost per passenger is computed to be a mere 25 cents per ticket, hardly a burden of consequence. This can be reduced even further with indigenous content of the protection system. An airliner is equipped with a variety of safety equipment such as Mae West life jackets, emergency chute, firefighting equipment, etc. Most of these may remain unused during the life cycle of the aircraft and yet, passengers bear the cost of all this equipment.
For civilian aircraft, the National Physical Laboratory and Instrument Research and Development Laboratory have been working on electro optic devices and systems. However, success in the indigenous effort suitable for avionics is not yet visible. There is undoubtedly a need to indigenously develop such protection system for Indian carriers. While regulatory issues can be addressed at the appropriate time, the proposal needs to be examined jointly by the Ministry of Civil Aviation, the Directorate General of Civil Aviation, the National Aeronautical Laboratory (NAL). A specific R&D project for this safety feature for civil aircraft should be initiated without delay at NAL.
The writer is a retired Air Vice-Marshal. E-mail: govindarajan_p @yahoo.co.in