Anti-missile technology offered for civil airplanes

 - February 1, 2007, 8:41 AM

Two companies are offering Israeli-built anti-missile systems to the civil aircraft market to protect airliners and business aircraft from the terrorist threat posed by shoulder-launched missiles, or Manpads (man-portable air defense systems). Both systems have proven pedigrees in the protection of military aircraft and both companies–Elisra, with its Lorica adaptation of the PAWS line of infrared missile warning systems, and ELTA/IMI, with its Flight Guard–are convinced that they can offer a credible and certifiable solution for operators who want protection from terrorists firing at their aircraft.

Elisra’s Lorica detects and tracks missiles using sophisticated algorithms, as well as image and signal processing. It tracks each missile’s trajectory to determine whether or not it directly threatens the aircraft. If the system determines the missile is a threat, it alerts the pilot and automatically deploys countermeasures to direct the missile away from the aircraft.

The company’s recommended countermeasures package for the civil market is the directional infrared system developed by fellow Israeli groups Rafael and Elbit. This system uses a laser beam to jam the missile’s guidance system. In military applications, chaff and flare dispensers are commonly applied countermeasures, but aviation authorities have questioned whether these are safe for use around civil airports.

In October, Miami-based Aviation Protection Systems (APS) obtained exclusive rights to offer the ELTA/IMI Flight Guard system to the U.S. market. According to company president Omer Regev, the system meets the existing requirements of U.S. FAR 25 rules and is therefore certifiable on civil aircraft.

Flight Guard uses active pulse Doppler radar with antennas installed throughout the airframe to detect missiles. The manufacturer claims that it is the only system that provides 100-percent coverage of the aircraft, with no unprotected “dead zones.” The system tracks any missile fired in the vicinity of the aircraft, making time-to-impact measurements so as to activate countermeasures effectively and to assign priority levels for countering a multi-missile attack.

Flight Guard’s countermeasures system uses new “dark” flares that divert threatening missiles away from the aircraft. As their name suggests, dark flares are not as bright as traditional flares and will not distract pilots since they are hardly noticeable to the human eye. They are considered more environmentally friendly in the context of a civil airport.
But if the countermeasures of anti-missile systems deflect missiles away from the aircraft they are protecting, is there not a danger that the missile could instead hit another aircraft, ground vehicles or a building at crowded airports? Regev
told AIN that a missile would lose most of its kinematic energy in the course of being diverted by the countermeasures and would therefore have insufficient “steering power” to hit another aircraft. “A missile whose seeker was locked on one aircraft cannot acquire another aircraft in its sights,” he explained. “It has a very, very narrow field of view. Bottom line: the scenario in question is not feasible.”

The key to ensuring full protection of an aircraft from missiles is to install the detection systems in such a way that they cannot be impeded by line-of-sight obstacles in any flight conditions (such as when the landing gear is down or flaps are extended fully). This means that each airframe to be fitted with the protection systems has to be surveyed thoroughly so that the optimum configuration for each type can be developed.

According to Nati Catran, Elisra’s deputy v-p of marketing, the actual protection requirements will vary significantly between military and civil aircraft types. Fighters are generally considered to be more at risk from air-to-air missiles aimed at
the upper hemisphere of their airframes, whereas civil aircraft are more likely to be targeted with surface-to-air weapons aimed at the lower hemisphere. This risk assessment forms a vital part of Elisra’s approach to installing the detection elements of the system.

Anti-missile System Installation

The need to carefully survey the airframe of each aircraft to be fitted with anti-missile protection systems obviously results in significant non-recurring expenses that would ideally be amortized over large numbers of installations for the same type. At face value this would make installations in individual business aircraft more costly than installations in much larger airline fleets.

Elisra declined to give a cost estimate for fitting Lorica to a business aircraft on the grounds that there would be so many variable factors for each customer. APS said that Flight Guard might cost approximately $1 million.

The installed weight of the Lorica detection system depends on the number of sensors that have to be provided but will probably be around 44 to 55 pounds per aircraft. In addition, there is the weight of the Rafael/Elbit countermeasures package, for which a weight estimate was not available at press time. The installed weight of Flight Guard on a business jet is expected to be around 100 pounds.

Both products are essentially stand-alone systems that do not require aircraft to have a particular avionics suite in place. According to Elisra, Lorica’s infrared-based measurement process is more accurate than alternative systems using radar or ultraviolet technology, meaning that the countermeasures beam can reach the missile’s seeker with great accuracy without the need for additional equipment.

According to APS, Flight Guard currently operates with a rate of one false alarm per 1,000 flights. Elisra has said that the false alarm rate for Lorica has been reduced to just one second per flight hour.

To date, Flight Guard has been installed on about 15 different aircraft types, including some Boeing airliners and unspecified business aircraft. According to APS, the system is now being prepared for between five and 10 airliner applications, and the company hopes to have FAA approval for one or more of these by early next year.

Regev told AIN that the certification process for Flight Guard on each aircraft is expected to take between two and five months. He estimated that the lead time between a customer placing an order and the system going into service would likely be around six months in each case.

Pilots are expected to need a one-hour training course in Flight Guard operations. Essentially, they need only activate the system while an aircraft is taxiing since all airborne operations are automatic.

Earlier this year, the U.S. Department of Homeland Security (DHS) awarded a pair of $45 million research contracts to groups led by Northrop Grumman and a U.S.-based division of BAE Systems to adapt their respective anti-missile protection systems for civil applications (see AIN October, page 4). This “Phase II” project is due to run through January 2006 with a view to helping U.S. authorities decide on the viability of imposing a requirement for such systems on the entire U.S. airliner fleet.

Catran said that he hopes Lorica, though not developed in the U.S., will receive a fair hearing from U.S. security and aviation officials despite its apparent “not invented here” disadvantage in the U.S. market. In his view, business aircraft owners and operators may well take the view that they cannot wait for the DHS and FAA to decide which is the most suitable anti-Manpads technology. As things stand, there is nothing to stop them from making their own system selection and having it certified aboard their aircraft.

Regev also expressed the hope that missile protection systems will be evaluated purely on their technical merits, rather than a predisposition to selecting equipment originating from the U.S. He also predicted that other national civil aviation authorities are likely to accept FAA certification for such systems.

Elisra, which has offices in the U.S., intends to supply Lorica directly to customers and to act as a single point of contact for operators. It will use various as yet unspecified installation and support partners in Israel and other countries to bring the product to the civil marketplace.