Commercial airlines aren’t the only planes under attack from shoulder-fired rockets and missiles these days, a number of slow-moving vehicles in the US Air Force have come under increased threat of being shot down. That’s why the USAF is outfitting many of them with sparkling laser blasters to confound inbound threats.
MANPADS (Man-Portable Air Defence Systems) are among the most pressing threats to American heavy aircraft — both the rotary and fixed wing varieties, ie the C-17 Globemaster and CH-47 Chinook — according to a 1999 US Transportation Command report to Congress. That year, Congress ordered the installation of IR-based countermeasures — specifically Northrop Gumman’s AN/AAQ-24 DIRCM system — on 59 SpecOps C-130 aircfraft.
A DIRCM (Directional Infrared Countermeasures) system is a beefed up, military spec version of the Israeli Sky Shield. Northtop Grumman calls its system the AN/AAQ-24 (V) NEMESIS, which is used by both the USAF and UK’s Royal Air Force. It detects the incoming threat using a passive missile warning system, then blinds the threats IR seeker head with infrared laser beams, steering the missile away from the aircraft without the need for pilot intervention. Basically, this fuselage-mounted device offers up a “fatter” target in the form of a “brighter” IR signature for the missile’s IR sensor to chase. The NEMESIS, according to Northrop Grumman, has yet to fail in 35 test firings aboard UAVs — what, it’s not like you’re going to lob a bunch of Stingers at a $US218 million Globemaster just to see if the laser dazzler is working as advertised.
When they were first installed at the turn of the century, the NEMESIS system ran a directed IR xenon arc lamp to generate its jamming signal, however, many of these units have been upgraded in recent years to use the laser-based Guardian system. You can now find these IR countermeasures on most C-17 Globemaster III, AC-130, MC-130, CV-22, and the CH-53E Super Stallions in active service. And, as part of the USAF’s Large Aircraft Infrared Counter-Measure program (LAIRCM), Northrop Grumman has just announced that it will be upgrading an additional 11 AC-130H’s, 12 MC-130U’s, and 5 EC-130J’s beginning early next year.
The NEMESIS is not the only dazzler flying the not-so-friendly skies. It actually lost out lon a $US68 million contract to BAE’s ATIRCM (Advanced Threat Infrared Countermeasures), a rival IR countermeasure system, in 2012. The ATIRCM works in much the same manner as the DIRCM — tracking inbound threats with the company’s common missile warning system then dazzling the missile out of the sky using concentrated laser beams — and has logged more than 125,000 hours of flight time since its introduction in 2009. The ATIRCM can be found on the CH-47 Chinook helicopter. [Military Aerospace – GlobeSec 1, 2 – NG – FAS – BAE]