Man-Portable Air Defence Systems, better known as MANPADS, are a continuing source of concern for operators of military and civilian aircraft alike. Fortunately, investments into Directional Infrared Countermeasures (DIRCM) technology is helping to protect aircraft.
First deployed in the 1960s, MANPADS are designed to protect infantry from low-altitude air-to-surface threats. Definitions differ, but typically MANPADS provide short-range air defence up to altitudes of between 15000 feet/ft (4572 metres/m) and 30000ft (9144m). The first generation of such weapons included the General Dynamics FIM-43 Redeye, which entered service with the US Army in circa 1967, and the KBM 9K32 Strela-2 which debuted in Red Army service one year later. The missiles equipping both weapons employed Infrared (IR) guidance; chasing the hot exhaust of an aircraft’s engine to reach their target. By and large, IR guidance has remained the method of choice for MANPADS designers, albeit with improvements in sophistication. For example, fourth generation MANPADS, including weapons such as Raytheon’s FIM-92E Block-I Stinger use a Surface-to-Air Missile (SAM) which has a wider field-of-view, compared to legacy versions of the FIM-92, according to its manufacturer. This allows the engagement of targets at comparatively longer ranges of circa 25000ft (8000m) compared to earlier versions of the weapon. While some MANPADS employ other guidance methods such as Command-Line-Of-Sight (CLOS); by which an operator manually steers the missile towards its target, such as the Thales Starburst MANPADS, and laser-guided weapons, by which a laser beam is shined onto a target, with the missile homing in on the laser’s reflection, such as Saab’s RBS-70 MANPADS family, it is electronic countermeasures against IR-guided MANPADS which are of interest to this article.
Traditionally, decoy flares have been used to protect military aircraft against all IR-guided Air-to-Air and Surface-to-Air Missiles (AAMs/SAMs). Decoy flares work using a simple principle; they are dispersed by an aircraft and ignite, usually using a metal, such as magnesium, which burns at a higher temperature than the aircraft’s exhaust, to provide a more tempting target for the incoming missile. Some decoy flare tactics call for the aircraft to pull away at a sharp angle after releasing the flare, and to then reduce engine power, and hence the engine’s heat signature, to cause added confusion for the incoming IR-guided missile.
Yet decoy flares have disadvantages: a finite number can be carried by an aircraft due to available space. The aircraft dispersing the flares has to detect the incoming missile as IR-guided weapons do not emit Radio Frequency (RF) energy unlike Semi-Active or Active-Radar Homing (SARH/ARH) guided AAMs/SAMs. Hence pilots may rely on a nearby aircraft to spot the incoming IR-guided missile, which is a complex exercise given that the missile may approach the targeted aircraft from aft, given that it is chasing the aircraft’s engine exhausts. Thirdly, as flares are pyrotechnics, some civilian airports may forbid flare-equipped military aircraft to their facilities amid safety fears. Finally, later generations of IR-guided missiles employ software algorithms allowing them to discriminate the heat signature of a flare from that of an aircraft’s engine exhaust.
One way around these challenges is for military aircraft to employ DIRCMs. Most DIRCMs follow similar principles: Their modus operandi depends on two essential elements; a method of detecting an incoming missile, to defeat the challenge of detecting the missile in the first place, and a method of defeating the missile. As noted above, unlike SARH/ARH-guided missiles, IR-guided SAMs/AAMs do not emit RF energy yet, like their quarry, they do emit an IR signature from their engine. This IR signature is detected by the DIRCM. Not only does the IR signature of the missile enable its detection, it also enables the missile to be tracked during its flight. At the same time the missile is being tracked, the DIRCM steers a powerful IR lamp towards the missile’s IR seeker. The lamp is used to shine a powerful beam of Ultraviolet (UV) light into the missile seeker, effectively dazzling it. A more complex variation of this technique is to shine a laser into the seeker using a specific waveform which confuses the seeker, and hence the missile’s guidance system, persuading the missile that it is off course relative to its target and causing the missile to continually adjust its flight profile so that it no longer proves a threat to the aircraft, or until the missile runs out of fuel.
DIRCM’s have a number of advantages compared to decoy flares: They not only defeat an IR-guided missile, but also detect it. Secondly, the number of missile attacks that flares can defect ultimately depends on the number of flares carried by the aircraft. A DIRCM, on the other hand, continually performs engagements as long as the aircraft’s engines are generating electricity. Moreover, as DIRCMs do not employ pyrotechnics, there are fewer problems regarding DIRCM-equipped using civilian airports. For this reason, DIRCMs have proven attractive for quasi-military aircraft, such as those flying heads of state or dignitaries, which may need to be protected, but which may have to use civilian airfields. In addition, some airlines, such as Israel’s national carrier, El Al, at a potentially heightened risk from MANPADS attack by insurgents, have also found DIRCMs to be attractive.
Designing a capable DIRCM is no easy task. Tony Innes, Leonardo’s head of DIRCM campaigns for its airborne and space systems, which produce the MIYSIS DIRCM product (see below) stresses that Size, Weight and Power (SWAP) consumption are all major considerations: “DIRCM systems have to be small, lightweight and draw very low power from the host aircraft, while providing optimum protection. In practice this means designing a complete detection and protection system capable of all-aspect (spherical) defence that would draw less than 500 Watts of electrical power and adds less than 88 pounds/lb (40 kilograms/kg) to the host aircraft.” This is a particularly important consideration for comparatively small platforms such as light utility helicopters or Unmanned Aerial Vehicles (UAVs) which may require DIRCM protection. Mr. Innes adds that responsiveness is another key design criteria. Typically, a DIRCM can perform its engagement in between two and five seconds from the detection of the missile until its neutralisation: “The DIRCM system must engage the IR-guided MANPADS threat immediately after launch, regardless of the range from which it was fired. For the most demanding, very short-range attacks, this requires exceptional response speed with very few moving parts (in the DIRCM).” Finally, the lasers which are used to defeat the missile must have the necessary power and agility: “This demands advanced laser technology (and) superior threat tracking accuracy,” Mr. Innes continues.
Regarding Leonardo’s MIYSIS product, Mr. Innes states that: “While being smaller, lighter and drawing less power than other DIRCM systems on the market, (MIYSIS) still offers the full spherical coverage required to counter advanced threats,” meaning that it is able to detect incoming SAMs/AAMs from any angle. Mr. Innes adds that the product has a modular design. In practice, this means that MIYSIS can be configured to work with Missile Approach Warning Systems (MAWS) which may already be installed on an aircraft, or can be delivered with a MAWS if this capability is lacking. Similarly, it can also work with existing defensive aids subsystems already installed on an aircraft such as flare and chaff (to counter RF-guided weapons) countermeasures dispensers. Another key part of Leonardo’s philosophy regarding the MIYSIS design is the drive for a low SWAP footprint to enable the product to be installed on a range of aircraft from light utility helicopters, up to freighters or airliners. Concerning customers, Mr. Innes is taciturn, although he did disclose that MIYSIS has been: “selected by a NATO (North Atlantic Treaty Organisation) customer for installation onto a fixed-wing platform in the very near future,” with a further three customers selecting the product for integration onto an aircraft configured for dignitaries, and two whom have selected it to equip undisclosed special missions aircraft.
Whereas products like Mysis can employ IR-based MAWS, Bird Aerosystems’ SPREOS DIRCM takes a slightly different approach in using a radar-based MAWS. This radar employs the Doppler Effect, by which the change in RF frequency from the radar’s transmitted pulse compared to the pulse’s echo from the target, is measured to determine the incoming missile’s velocity and position relative to the aircraft. The use of radar, the company told AMR, results in an approach to detecting the missile that: “completely eliminates all of the false alarms of the system and ensures that jamming will be activated only on real threats.” In practice, this avoids the DIRCM being triggered by other heat sources, such as decoy flares ejected by friendly aircraft nearby, which might cause the countermeasure to be activated. Bird Aerosystems continues that it is currently seeking customers for the SPREOS, having launched it at the Eurosatory defence exhibition held in Paris this June. Other new products to join Bird Aerosystems’ SPREOS include Indra Sistemas InSheild, which has been selected to equip the Airbus A400M turboprop freighters of the Ejército del Aire (Spanish Air Force). Like other systems surveyed in this article, it employs an open architecture to allow it to easily accommodate new technologies during its life.
Israel is no stranger to the IR-guided AAM/SAM threat: On 24 November 2002, an Arkia Airlines Boeing 757-300 airliner flying from Moi airport, near Mombasa in southern Kenya to Tel Aviv, was attacked by Islamist insurgents using a 9K32 Strela-2 MANPADS. Such events have focused the mind of Israeli defence electronics specialists with Elbit Systems providing the MUSIC DIRCM family which unsurprisingly equips a number of Boeing airliners, including the 737, 747, 757, 767 and 777 families, all of which (sans the 757) are operated by El Al. Military aircraft such as the Airbus A400M turboprop freighters of the Luftwaffe (German Air Force) also carry MUSIC. According to Dan Slasky, the vice president of Elbit’s electro-optics and laser business unit, explains that the MUSIC product family is the only DIRCM operationally installed on commercial airliners. This translates into tangible benefits for military operators because: “The systems are operating almost nonstop, just like a commercial airliner, which flies almost constantly, except to embark and disembark passengers at the terminals. The result is that Elbit’s DIRCM systems have logged tens of thousands of operational flight hours.”
Much like the significant number of flying hours accrued by the MUSIC DIRCM in the civilian domain, recent, and ongoing combat operations are enabling DIRCMs to show their worth. BAE Systems’ AN/ALQ-212 ATIRCM (Advanced Threat Infrared Countermeasures) product is in service onboard the US Army’s Boeing CH-47D/F Chinook heavy-lift helicopters, and has, according to Tom Kirkpatrick, the firm’s ATIRCM programme manager, been protecting these aircraft in the Afghan and Iraqi theatres “for many years.” This has led to the AN/ALQ-212 accumulating over 135,000 combat flying hours on the CH-47D/F and other undisclosed airframes. In addition to the US Army, BAE Systems announced in March 2015 that the AN/ALQ-212 had been approved for international sale by the US Department of Defence.
From a technological perspective, future DIRCM development could see the continued imperative to reduce the SWAP absorbed by such countermeasures. One potential development advocated by Bird Aerosystems is the use of distributed lasers around and aircraft’s fuselage, as opposed to positioning these in a single location on an aircraft which adds weight in a specific area, potentially affecting an aircraft’s performance. Locating the lasers used to jam an incoming IR-guided AAM/SAM laround the aircraft could distribute weight, while at the same time removing the single point of failure for lasers mounted in the same unit as the DIRCM’s other working parts.
Laser technology is also expected to develop further. Elettronica, which provides its ELT/572 DIRCM equipping the Aeronautica Militaire (Italian Air Force) Lockheed Martin C-130J turboprop freighters and AW-101 helicopters, sees this dimension of DIRCM technology evolving. According to a written statement provided to AMR by the company: “laser sources technology such as the quantum cascade laser … giving the possibility to increase the number of laser emitters for further IR bands,” which may be used by missile IR seekers in the future.
Regarding the future market for DIRCMs, Bird Aerosystems is bullish vis-à-vis demand: “The main driver for introducing a DIRCM solution … is the growing threat of MANPADS to both military and civil aviation.” The firm adds that as there is an increasing demand, it expects the procurement costs for DIRCMs to progressively decrease: “Additionally the increasing maturity and decreasing cost of a DIRCM system enables it to be offered on a much wider basis to both the military and (dignitary) markets.” This demand for DIRCMs is observed by Joshua Pavluk, the principal of Avascent, a consultancy based in Washington DC: “Overall military demand for DIRCMs is on an upswing at the moment. We estimate global military spending in 2016 at nearly $500M, which is actually higher than last year’s total spend of about $400M. Looking ahead, next year’s spend will be higher yet.” Mr. Pavluk attributes this to: “continued threats from MANPADS and a push to modernise existing aircraft (with DIRCMs).” He expects the strongest demand for DIRCMs to come from the US military: “The US military is by a wide margin the single largest buyer of DIRCM systems, at over 60 percent of the global total from 2017 to 2021. The Northrop Grumman AN/AAQ-24(V) LAIRCM (Large Aircraft IR Countermeasure is one driver) of recent acquisition in the US.”
Beyond the United States, Mr. Pavluk expects the Middle East and North African regions to account for 15 percent of overall DIRCM spending between 2017 and 2021, with the demand from Europe being low, primarily because of the dearth of new military aircraft acquisitions compared to these other areas in the same timeframe. In terms of aircraft types, Avascent argues that the lion’s share of demand will come from DIRCM installations for large, fixed-wing aircraft such as Boeing C-17A Globemaster-III and C-130J turbofan and turboprop freighters, with a continuing demand for DIRCMs to protect rotorcraft.
However, Mr. Pavluk warns that, over the long term, DIRCM spending could reduce: “DIRCM spending is going to be increasingly constrained over the next five years … The relatively high cost of systems means that DIRCM is not a taste that will be for everyone. For some, the benefits outweigh the costs but there are others who simply don’t have the budget … Even though the MANPADS threat is generally high, some countries either won’t face a significant danger or will choose to take on more risk. Furthermore, delays or cancellations of platform acquisition programmes would also have a domino effect on DIRCM acquisition plans.”
Furthermore, Mr. Pavluk cautions that the uptake of DIRCMs by civilian airline operators is likely to be much slower: “On the other hand the civil market is yet to adapt (to countermeasures such as DIRCM) and although they offer protection to aircraft, passengers and crew, unless induced by political legislation, safety regulations and a willingness to support the cost of upgrade and support by a third party (such as a government) the acceptance of these systems to the civil market will take time.” Quite simply, airlines are unlikely to be willing to fork out the money necessary to fit expensive DIRCMs to their airliners as they continue to work to keep costs down to attract passengers: “The costs are simply too high for many airlines and most are not receiving financial incentives from government to install the systems.” Regrettably it may take the shooting down of an airliner with a MANPADS beyond hostile areas such as the Syrian or Iraqi theatres, or other war-torn parts of the world such as South Sudan, before DIRCMs become an imperative for airlines.