Keeping Your Ears Open

This is an article published in our Airborne Electronic Warfare Compendium from June/July 2017.

RAF RC-135W aircraft
USAF and RAF RC-135W aircraft have played an important role in gathering communications intelligence regarding ISIS activities in the Iraqi and Syrian theatres. (USAF)

The past twelve months has witnessed interesting activity in the Electronic Intelligence (ELINT) gathering domain of airborne electronic warfare, with the Syrian and Iraqi threatres, and the Baltic region, experiencing energetic activity in this regard.

On 25th April, two United States Air Force (USAF) Lockheed Martin F-35A Lighting-II fighters from the USAF’s 34th Fighter Squadron were deployed from Lakenheath airbase in eastern England, to Amari airbase in northern Estonia, arriving in Estonia at 1100 Zulu (Z). An official statement regarding the deployment released by the USAF stressed that it: “has been planned for some time (and) has no relation to current events.” Adding that the move: “allows the F-35A to engage in familiarisation training within the European theatre while reassuring allies and partners of US dedication to the enduring peace and stability in the region.” The Baltic region has been a tense place since the Russian government’s annexation of Crimea, formally part of Ukraine, on the Black Sea during Moscow’s intervention in the Ukrainian Civil War in March 2014.

F-35A fighters
The USAF performed a deployment of F-35A fighters to Estonia in April; a deployment which was accompanied by significant ELINT gathering activity. (USAF)

Yet, the deployment of the F-35As was not the only event in late April which got plane spotters’ tongues wagging, and fingers tapping, as illustrated by the quantity of online coverage of the event. The arrival of the F-35As in Estonia was punctuated by some interesting ELINT activity. A collection of plane spotters listing to air band radio, and observing online air traffic information services, noticed that the F-35A deployment occurred simultaneously with flights by one USAF and one Royal Air Force (RAF) Boeing RC-135W Rivet Joint/Airseeker, and a single USAF RC-130U Combat Sent ELINT gathering aircraft. Both these platforms are tasked with collecting, identifying, locating and analysing Radio Frequency (RF) emissions. According to open sources, the RC-135W is primarily focused on collecting Communications Intelligence (COMINT), while the RC-130U is principally concerned with ELINT collection vis-à-vis radar transmissions. All three aircraft performed ‘racetrack’ orbits; the two RC-135W aircraft northwest of Russia’s Kaliningrad enclave to the northeast of Poland, while the RC-135U flew over Estonia itself, close to the Estonian-Russian border. The F-35As completed their deployment at 1443Z and subsequently returned to the UK, the RC-135U/W jets leaving the area shortly afterwards. 

RC-135U Combat
The USAF deployed an RC-135U Combat Sent to accompany the recent deployment of F-35A jets to Estonia. The aircraft may have been used to gather information on Russian radar, or to act as a deterrent. (USAF)

Baltic Machinations

Neither the USAF nor the RAF has, unsurprisingly, revealed the activities of these RC-135U/W aircraft. The purpose of their deployment could have been two-fold: The F-35A’s trip to Estonia was part of the first ever deployment to Europe of this fifth-generation fighter which was designed from the outset to have a low radar cross section. Flying an aircraft with this degree of sophistication close to Russian territory may have prompted the USAF and the RAF, which will operate the F-35B variant of the aircraft from later this decade, to perform ELINT collection to see how Russia’s Integrated Air Defence (IADS) system, notably its ground-based air surveillance radars and the radio communications which tie an IADS together, reacted to the deployment of such an aircraft. Secondly, some analysts in the online air traffic information service community have speculated whether the deployment of these aircraft was intended to have a deterrent effect to persuade the Russians to keep their radars inactive while the F-35As were deployed to Estonia. Some observers have said that the fact that all three RC-135U/Ws kept their ADS-B (Automatic Dependent Surveillance-Broadcast) RF transponder active during their flights, hence making it possible to track these aircraft using online services such as FlightRadar24, indicated that the RAF and USAF wanted their aircraft to be seen. Those same observers stated that when such aircraft are collecting ELINT over the Iraqi and Syrian theatres they routinely keep their ADS-B transponders inactive to help mask their operations.

Middle East

Beyond the Baltic, energetic airborne ELINT-gathering activity has been witnessed in the Syria/Iraq theatre as the US-led coalition (known as Combined Joint Task Force-Operation INHERENT RESOLVE/CJTF-OIR) continues its fight against the Islamic State of Iraq and Syria (ISIS) insurgent group. Again, the online air traffic information community has played a major role in tracking ongoing activity. For example, in February and March 2017, the US was actively seeking Abu Bakr al-Baghdadi, ISIS’ leader whom was believed to be in Mosul in northern Iraq; for which the battle to liberate the city from ISIS control was still ongoing at the time of writing. Reports have noted that Beechcraft Super King Air-300 turboprop transports, believed to be equipped with ELINT gathering equipment had been seen circling Mosul during the battle, which commenced on 16th October 2016. These aircraft said to be hunting for RF transmissions that might betray Mr. Al-Baghdadi’s location. A number of interesting quasi-military airframes have been detected operating over Mosul. These include a Pilatus PC-12/45 turboprop transport with a registration number of N56EZ which open sources note as owned by the Sierra Nevada Corporation. This firm has a proven track record in providing airborne electronic warfare/ELINT systems, and converting aircraft to this role. Other aircraft which have been detected flying over Mosul include numerous US Army Beechcraft MC-12W Project Liberty ISR (Intelligence, Surveillance, Reconnaissance) gathering aircraft which can perform tactical and operational ELINT gathering, notably for RF communications.

MC-12W ELINT gathering aircraft
US Army MC-12W ELINT gathering aircraft are thought to have played a major role in locating senior ISIS cadres during combat operations in Mosul. (USAF)

As noted above, the use of ELINT to track down and eliminate key ISIS individuals in the Iraqi and Syrian theatres has become a modus operandi of choice for CJTF/OIR. As Professor David Stupples, director of electronic warfare research at City University, London noted: “ISIS’ levels of communication is very rudimentary using standard cellphones, some Very High Frequency (30 megahertz/MHz to 300MHz) and some satellite communications.” Prof. Stupples continued that CJTF/OIR’s electronic warfare concept of operations in these theatres is to use platforms such as the RC-135V/W to “hoover up” the electromagnetic spectrum, typically in the three megahertz to 300 gigahertz waveband to determine those RF signals which could originate from ISIS members. This is primarily an exercise in gathering the ELINT metadata dubbed: “data that provides information about other data” according to the Merriam-Webster English Dictionary. This data then has to be analysed to tease the possible ISIS signals from the general electromagnetic environment. This can be a challenge, Prof. Stupples added, as ISIS has demonstrated that it can encrypt its communications. For example, the militia is known to use communications encryption which is commercially available online, alongside AES (Automatic Encryption Standard) electronic data encryption protocols established by the US National Institute of Standards and Technology. In addition, Prof. Stupples noted, all cell phones have their own encryption in the form of a unique encryption key needed to join a specific network, and the cell phones’ own key which is not unique. These keys combine to create a unique key for the cellphone every time it joins the network. Such information can be collected by an aircraft such as the RC-135W and then analysed on the ground.

RAF RC-135W aircraft
USAF and RAF RC-135W aircraft have played an important role in gathering communications intelligence regarding ISIS activities in the Iraqi and Syrian theatres. (USAF)

That said other information can be interpreted by the aircraft’s organic analysts. For example, if it is determined that a particular cellphone was being used when, on 30th August 2015, ISIS destroyed the Temple of Bel, founded in the year 32 in the central Syrian city of Palmyra, and that cellphone is then detected once more during further ISIS actions such as the ongoing Battle of Raqqa in northern Syria, which commenced on 6th November 2016, then an ELINT picture can begin to be established potentially linking that cellphone to an ISIS cadre. The further detection of such transmissions could then be useful for the geolocation of that cellphone, and hence the direct attack of that individual. This is one mechanism, Prof. Stupples continued, by which high value ISIS individuals can be tracked down and killed.

The Threat

As this compendium will illustrate, investment around the world is flowing into the procurement of ELINT systems and platforms, alongside continuing investment into airborne electronic warfare systems for both aircraft self protection and for operational and tactical missions such as the suppression of enemy air defences. At the same time, as the compendium’s conclusion will illustrate, minds are concentrating not only on emerging technologies such as cognitive electronic warfare, but also how to manage the mass of ELINT gathered by airborne platforms as the electromagnetic spectrum becomes an increasingly congested place worldwide, caused not least by the proliferation of civilian smartphones: The statistics website estimates that the number of smartphone users globally will increase to 2.87 billion by 2020, from 2.32 billion today. Both this growth of smartphone use and the significant employment of ELINT gathering elements in ongoing conflicts illustrates that: “EW continues to be a valued resource onboard airborne platforms both against traditional and new generation threats,” Elettronica stated in a written statement.

US defence secretary Ashton Carter
Speaking in February 2016, former US defence secretary Ashton Carter outlined the potential strategic challenges that the US and its allies are expected to face around the world in the coming years. (US DOD)

The company’s thinking is underlined by the expectations regarding future threats articulated by Ashton Carter, the former US defence secretary, in his February 2016 preview of the US Department of Defence’s 2017 budget request. Mr. Carter stated that Russian aggression in Europe, the rise of the People’s Republic of China in the Asia-Pacific, the Democratic People’s Republic of Korea, the Islamic Republic of Iran and the ongoing activities of ISIS all represent strategic challenges for the US and its allies in the years ahead.

by Thomas Withington