The Indian CH-47F Chinooks have the standard mount used on the side of the sponson toward the rear with a pair of Elbit PAWS-series warning sensors already installed

Directional infrared countermeasure (DIRCM) systems, which use lasers to blind and confuse the seeker on infrared-homing missiles, are becoming an increasingly ubiquitous feature on U.S. military helicopters and other aircraft. Now a picture has emerged that is one of the first to show an MH-47G Chinook from the U.S. Army's elite 160th Special Operations Aviation Regiment, also known as the Night Stalkers, with such a defensive suite, known as the AN/AAQ-24.

The U.S. Army Special Operations Aviation Command, which oversees the 160th, posted the picture of the DIRCM-equipped MH-47G on its Instagram page on Jan. 3, 2020. The caption does not say where or when the picture was taken.

Northrop Grumman's AN/AAQ-24 system, the most recent versions of which are somewhat confusingly referred to as the Large Aircraft Infrared Countermeasure (LAIRCM) system, consists of two pointer-trackers and an array of warning sensors all linked to a central control unit. The sensors detect incoming heat-seeking missiles and then cue the pointer-trackers to engage them by firing a low-power modulated laser beam into their seeker, causing them to fly off course.

The light grey sensor turrets are visible mounted at the rear of the MH-47G Chinook's side sponsons. The warning sensors are visible around the nose, the sides of the forward fuselage behind the cockpit, on the front rotor housing, as well as the turret mounts themselves.

Its name notwithstanding, sub-variants of the AAQ-24 system have been in service on a wide array of U.S. Marine Corps, Navy, and Air Force aircraft and helicopters, including the Air Force's highly specialised VC-25A "Air Force One" and C-32A "Air Force Two" jets, as well as with foreign militaries, for years now. U.S. Special Operations Command first approved an urgent operational needs statement outlining a requirement for these systems for special operations aircraft and helicopters, including the 160th's MH-47s and MH-60s, in 2015. The following year, SOCOM began considering the available options, before ultimately settling on the AN/AAQ-24.

It's somewhat curious that the urgent SOCOM requirement for DIRCM systems only came in 2015, given that these systems had already been in increasing use, including within the U.S. military, starting in the late 1990s. SOCOM was directly involved in the development of the original version of the AN/AAQ-24, as well, according to Northrop Grumman.



One of US Army equipped with AN/AAQ-24 directional infrared countermeasure (DIRCM) system

When it comes to the 160th's MH-47s, specifically, these helicopters are already the most heavily modified and well-protected Chinooks in the world, with specialised features to reduce their vulnerability, specifically to shoulder-fired, short-range, heat-seeking surface-to-air missiles, also known as man-portable air defence systems, or MANPADS. These include shrouds on the engine exhausts to reduce their infrared signature, numerous flare dispensers, missile warning sensors, and more.

SOCOM's urgent request did coincide with increasing operations in Iraq and Syria. In those countries, there had been a particularly pronounced concern about the proliferation of MANPADS, including among non-state actors, such as ISIS. These missiles are also a growing threat elsewhere around the world. New types increasingly feature counter-countermeasures, such as advanced imaging infrared seekers, which make them less vulnerable to traditional decoy flares. As such, this makes DIRCM suites a valuable addition, especially to helicopters, in general.

It's not clear how long the 160th has actually been using the AN/AAQ-24 on its MH-47Gs. There is at least one other set of pictures, dated January 2019, showing one of the special operations Chinooks equipped with this DIRCM system available through the Defense Visual Information Distribution System (DVIDS).

It's also interesting to note that the U.S. Army began flight testing an AN/AAQ-24 installation for conventional CH-47F Chinooks in July 2017, but that work got "halted because of poor system performance" before the end of that year, according to a report from the Office of the Direction of Operational Test and Evaluation. "Incorrect ATW [Advanced Threat Warner] sensor placement on the CH-47F aircraft caused poor system performance."

The Army was also working on AN/AAQ-24 installations for the AH-64 Apache gunship and UH-60 Black Hawk transport helicopter, at the same time, efforts that also ran into setbacks. A number of Apaches and Black Hawks did ultimately enter service with their respective subvariants of this DIRCM system, though.

It's unclear if the Army ultimately resolved those issues or if the configuration the 160th is using on its MH-47Gs is a version of the one developed for the regular CH-47Fs. The MH-47G airframe is not identical to the CH-47F, with the special operations variant having notably larger side sponsons. It also has various additional features on the nose and forward fuselages, such as a sensor turret, in-flight refueling probe, and radar.

The AN/AAQ-24 configuration for the MH-47G does appear to use a standardised mount to attach the pointer-trackers to the side sponsons. Canada's CH-147F Chinooks, for instance, uses an earlier generation of the Northrop Grumman DIRCM system that features different pointer-trackers, but uses the same general mounting arrangement.

India's new CH-47Fs have the same mounts, as well, with pictures showing Passive Airborne Warning Systems (PAWS) series of warning sensors from Israel's Elbit installed on them at present. PAWS and its variants are associated with versions of Elbit's Music series of DIRCM systems, a version of which Indian CH-47Fs look set to receive in the future.

The U.S. Army had intended for the AN/AAQ-24 to serve as an interim replacement for the older BAE Systems AN/ALQ-212 Advanced Threat Infrared Countermeasures (ATIRCM) system on its CH-47F, as well as its AH-64s and UH-60s. The service is now planning to install the Common Infrared Countermeasures (CIRCM) system on all of its helicopter types.

The CIRCM is another Northrop Grumman product, which is already entering service on its UH-60M Black Hawks. You can read more about the ATIRCM and the CIRCM programs in this past War Zone piece.

It's not clear whether the 160th is also planning to eventually move from the AN/AAQ-24 to the Army-standard CIRCM. Whatever the case the Night Stalker's MH-47Gs now have an important additional defensive capability available to protect them from the threat of MANPADS.