LAIRCM: Protecting the Military's Big Birds

KIRTLAND AIR FORCE BASE, N.M. -- How do you protect the U.S. military's large aircraft that perform missions ranging from air refueling to troop and supply transport? The slower speeds of these aerial workhorses along with limited evasive maneuverability and large radar and infrared signatures result in a very large bull's-eye for the enemy.

The threat to these aircraft come in the form of air-to-air missiles, surface-to-air missiles, and one of the most dangerous threats, the shoulder fired, infrared, man-portable air-defense missiles, commonly known as MANPADS. More than 700,000 MANPADS are estimated to have been produced in the past 30 years. During the past 25 years, MANPADS in general have been responsible for 90 percent of aircraft combat losses with 80 percent of the fixed-wing aircraft losses during Operation Desert Storm attributed to MANPADS, according to GlobalSecurity.org.

Initially, the Department of Defense focused on acquiring infrared, or IR, countermeasure systems to protect large aircraft, such as the C-130 and the C-17. These kinds of large planes have traditionally defended themselves from heat-seeking missiles by dropping flares. But, as IR missiles became more advanced, they also became more resistant to this kind of countermeasure.

The Large Aircraft Infrared Countermeasures system, known as LAIRCM, is an answer to the need to provide an interim capability to protect Air Force transport aircraft from MANPADS, which remains a menace to U.S. military aircraft operating in Afghanistan and Iraq. The LAIRCM system is a laser-based, IR countermeasure system designed to enhance individual aircraft survival by providing an effective defensive capability for tanker and transport aircraft, specifically protecting against vehicle launched and shoulder-fired, IR missiles. The LAIRCM system autonomously detects and declares IR missile threats, then tracks and emits IR laser energy to disrupt and jam the missiles' guidance, causing even the most advanced heat-seeking missiles to miss its target.

Advances in technology continue to allow improvements to the LAIRCM system. The Air Force Operational Test and Evaluation Center finished an operational assessment of the LAIRCM Phase II system in October 2006. The operational assessment focused on assessing the progress of the system to provide large aircraft survivability against IR missile threats during global air operations. Testers at AFOTEC's Detachment 2 at Eglin AFB, Fla., evaluated the Next Generation Missile Warning Subsystem's, or NexGen MWS, ability to detect IR threats, both air-to-air and surface-to-air, as well as the ability of the new laser turret, known as Guardian, to neutralize IR threats and ensure aircraft survivability.

LAIRCM Phase I of the program focused on equipping C-17 and C-130 aircraft with currently available technology as a stop-gap measure. Phase I used an ultraviolet missile warning system, a countermeasure processor and a small laser turret assembly. This system is currently employed on the C-17 and will be installed on the C-130.

The LAIRCM Phase II system provides a NexGen MWS capability for the LAIRCM system and a smaller laser turret. The Phase I MWS detects threat signatures in the ultraviolet region of the electromagnetic spectrum. The NexGen MWS operates in the infrared region where it provides better resolution, better performance in clutter environments, and increased range of detection compared to the Phase I MWS.

AFOTEC continues to provide the required operational testing and evaluation of aircraft countermeasure systems that the Air Force is developing in response to the evolving threats of IR surface-to-air and air-to-air missiles. The next phase of testing on the LAIRCM system is an initial operational test and evaluation that is scheduled later in 2008.

The future of IR countermeasures is looking toward a closed-loop IR countermeasures, or CLIRCM, capability. Proposed closed-loop IRCM would detect and classify incoming missiles, then emit a custom jamming energy to defeat the specific threat. The process would cause the missile to break its lock-on with the aircraft, allowing the system to detect and defeat another potential target after only a few seconds. Current open-loop IRCM systems, like LAIRCM, do not defeat targets with specific jams; therefore, the possibility exists that a missile could reacquire its target if the jammer moves to defeat another missile.

The continued development and improvement of these systems will ensure that U.S. transport aircraft, that play an imperative role in continuing military operations, are protected from radar seeking missiles.