A low-cost infrared countermeasures system is one of eight candidate concepts shortlisted for development as airliner missile-defence systems by the US Transportation Security Working Group. Full-scale development contracts are due to be awarded in October by the Transportation Safety Administration.

Sanders Design International's (SDI) spatial infrared countermeasures (SICM) system uses high-intensity heat sources on the wing and fin tips that are sequenced to fool the missile's proportional-navigation guidance system into thinking the aircraft is accelerating, causing the weapon to aim wide and miss its target. The approach has been described as "virtual flares", says SDI president Al Hastbacka.

"Infrared jammers go after the seeker. SICM goes after the guidance, by imparting apparent acceleration to the target and causing the missile to lead its target," he says. The system, to be manufactured for Peabody, Massachussetts-based SDI by Analogic, will cost around $250,000, compared with around $2 million for a laser-based directed infrared countermeasures (DRICM) system, says Hastbacka.

Drag would be less than for the underfuselage "canoe" pod needed to house a DIRCM turret, Hastbacka says. The "glow-bar" heat sources are about 100mm (4in) in diameter and would retract to reduce drag. The system would be turned on before take-off and landing and off at altitude.

Source: Flight International