NATO’s Airborne EW

As the UK and other European NATO members attempt to adapt their air forces to better meet the threat of wider Russian military aggression in the coming years, airborne electromagnetic warfare (EW) is a key area where non-US capabilities are in worryingly short supply across the Alliance. Investment in European airborne electromagnetic attack (EA) can, if done correctly, offer rapid increases in the survivability and lethality of existing air force aircraft and weapon systems. By the same token, however, significant expansion of capacity in Europe to rapidly update EW mission data is also essential in order to maintain current air capabilities in the face of an increasingly rapid pace of Russian radar and EW system adaptation – in part driven by the pressures Russia faces in its war against Ukraine.

Airborne EW capabilities play several key roles in high-intensity air operations, and are especially important for the vital suppression and destruction of enemy air defences (SEAD/DEAD) mission set. The first role is defensive electronic countermeasures (ECM), where aircraft employ directed jamming effects to try to degrade and break the lock of either the radar of a hostile aircraft or surface-to-air missile system that is targeting them. The second role is offensive stand-off escort jamming, where specialised aircraft with high-powered jamming arrays either mounted in the airframe or in underwing pods degrade hostile airborne and ground-based radar threats from much further back. This enables them to significantly increase the survivability of other attack aircraft or weapons in a strike package that is closer to the threat. The third role is offensive stand-in jamming, where stealth aircraft or advanced decoys, missiles or UAVs conduct suppressive jamming on specific high-priority threat systems from comparatively close range. This is done to provide a temporary window of access for other aircraft or weapons to get through to targets in the area.

Dependency on the US

Currently, NATO’s air forces are heavily dependent on US Air Force (USAF) and US Navy (USN) aircraft to provide both stand-off and stand-in jamming against a high-end threat like Russia, although several other countries’ fighter fleets have impressive ECM capabilities already for close-range self-defence. NATO’s primary stand-off jamming capability is provided by USN EA-18G Growler aircraft and the USAF EC-130H Compass Call, which is now being replaced by the new EA-37B. SEAD support is also provided by the Tornado electronic combat/reconnaissance (ECR) aircraft of the Italian Air Force and German Air Force, as well as the F-16CM “Wild Weasels” of the USAF’s 480th Fighter Squadron in Germany. However, in terms of EA systems, these Cold War-era aircraft only carry self-protection jamming equipment that is increasingly obsolescent against the more modern Russian threats if used without cover from the more powerful US stand-off systems like the EA-18G and EA-37B. The Tornado ECRs are also only available in small numbers, and the majority of the USAF F-16CM fleet is based in South Korea and Japan. It is notable that in almost any high-end NATO SEAD/DEAD exercise, USN EA-18Gs perform the majority of the EA support, since they offer by far the greatest capability in their class.

Significant expansion of capacity in Europe to rapidly update electronic warfare mission data is essential in order to maintain current air capabilities in the face of an increasingly rapid pace of Russian adaptation

However, the USN attempted to withdraw its land-based EA-18G units from the European theatre in mid-2022 to bolster its presence in the Indo-Pacific and Middle East. The Growler is a critical part of the Carrier Air Wing force structure, and demand for its capabilities greatly outstrips the number of squadrons available to deploy at any given time. That attempt did not immediately lead to withdrawal, but relying on US EA support as a lynchpin of European NATO SEAD/DEAD capabilities remains a high-risk posture. One of the most likely scenarios in which Russia might risk direct conflict with a NATO member is if the US is drawn into either a serious military standoff or an actual conflict with China in the Indo-Pacific. In any clash over Taiwan or in the South China Sea, airborne EA assets would be some of the most in-demand in the entire US arsenal, meaning few if any EA-18G Growlers or USAF EA-37B Compass Call aircraft would be made available to respond to a Russian threat in Europe during a concurrent crisis. This means a much greater burden of the high-end EW effort would fall on European capabilities than in any previous post-Cold War conflict.

European and UK Airborne EW Hardware

The French Rafale and Swedish Gripen both offer impressive ECM self-protection capabilities, but neither are currently equipped for dedicated stand-off or stand-in jamming. This follows a pattern across NATO air forces where EW in the air domain was primarily thought of as an aircraft self-defence capability outside of specialist units during decades of counterinsurgency operations. However, faced with the challenge of the extensive Russian integrated air defence system, European air forces now face a requirement for much greater offensive stand-off and stand-in jamming capabilities to support SEAD/DEAD operations at scale. Germany has ordered the development of 15 “Eurofighter EK” aircraft from existing airframes, designed to replace its ageing Tornado ECRs in the SEAD role. The EK will use an active electronically scanned array (AESA) radar developed by Hensoldt; the Aeraxis EW sensor suit from Saab; and AI-enabled software and mission data by Helsing. However, it will not be certified as combat ready until 2030, and that timeline assumes that the programme faces no delays.

The F-35 is also a potent airborne EW asset, and one that has been purchased by a large number of NATO members including the UK, the Netherlands, Norway, Italy, Finland, Denmark, Belgium, Poland, Germany and Czechia. Despite being primarily designed for low-observable strike and SEAD/DEAD operations, its APG-81 radar and advanced mission systems enable highly effective ECM for self-defence and also provide potent stand-in jamming and potentially limited stand-off jamming capabilities against both airborne and surface threats. Even a few F-35s can greatly enhance the survivability of not only their own formation but also allied assets operating alongside them as part of composite air operations. However, the F-35 still faces tactical limitations that make it difficult to generate sustained EW effects for more than short bursts, and pilots potentially risk compromising their position to hostile sensors when emitting in this way. More advanced EA capabilities that formed part of the intended Block 4 upgrade have in many cases been delayed until at least 2029 by issues with the electrical power generation capacity of the existing F-135 engine and hardware manufacturing bottlenecks. Most countries that have bought F-35s also lack the capacity or rights to modify or create their own mission data sets, and instead rely on the US for their mission data and threat library updates.

However, this does not fully apply to the UK since it is part of the Australian, Canadian and United Kingdom Reprogramming Laboratory (ACURL), which enables it to generate UK-specific mission data. Beyond the ACURL for its F-35B fleet, the UK has several national airborne EW development and procurement programmes. For stand-in jamming effects, the RAF is exploring options for stand-in jamming payloads for its Autonomous Collaborative Platform (ACP) programme, and continues to fund development work on a stand-in jamming variant of the MBDA SPEAR 3 miniature cruise missile called SPEAR EW. Potent ECM capabilities are also a core feature of the new ECRS Mk2 AESA radar, which is being procured to eventually be retrofitted onto the 40 Tranche 3 aircraft in the RAF Typhoon fleet. However, SPEAR EW has not actually been ordered so far, and the ECRS Mk2 has been developed very slowly compared to AESA radar development programmes for comparable fighters. On current timeframes, RAF Typhoons with the new radar are unlikely to be in service on the frontlines before the late 2020s. The threat outlook in Europe, therefore, would seem to suggest that allocating increased funding and priority to whichever of these existing programmes can offer the most rapid path to procurement and introduction to service is something that should be seriously considered. Given the lack of funding so far for ECRS Mk2 radar sets for the remaining 77 RAF Tranche 2 Typhoons, urgent updates to the capability of their existing ESM and Defensive Aid Sub-System (DASS) suites should also be examined – especially if novel software techniques could improve capability faster than hardware upgrades planned but not yet funded within the Typhoon LTE construct.

The Crucial Role of Mission Data and Software

Investment in platforms, sensors and effectors – however important – is also insufficient by itself. EW effectiveness requires electronic intelligence (ELINT) collection capabilities to record hostile radar emissions and covert intelligence collection in order to help understand enemy systems in depth. Many of these ELINT gathering capabilities can be and are mounted on a variety of assets besides fighter aircraft, with the RC-135W Rivet Joint and P-8 Poseidon being notable but by no means exclusive examples. One key objective must be to make better use of the huge amount of such data that is naturally collected by the increasingly capable digital sensors on most airborne and some land and maritime platforms during everyday training and on operations, since the vast majority of this data is not currently captured and fed into the EW analysis and mission data cycle. Beyond improving collection, however, making use of ELINT also requires the ability to rapidly convert collected data on hostile systems into frequent mission data updates in order to enable aircraft and EW systems to remain effective once a conflict starts. Outside the US, where once again the vast majority of NATO capacity and capability resides, the three most capable countries in terms of collection, ELINT analysis and mission data update generation are France, Sweden and the UK. Other countries such as Germany, Italy and Czechia also have centres of expertise and capability, but at a significantly smaller scale.

The UK has long maintained greater mission data generation capacity than most other NATO allies, largely through the Joint Electronic Warfare Operational Support Centre (JEWOSC) – a Strategic Command asset that is located within the RAF Air and Space Warfare Centre at RAF Waddington. However, dependency on data collected by the US for the JEWOSC’s work is still high, and budgetary and personnel limitations prevent major expansion of capacity without leveraging new techniques such as those offered by machine learning (ML) and artificial intelligence (AI) toolsets. The task is more complex and simultaneously more essential than ever before, as Russian forces already make widespread use of sophisticated digital radar and EW systems with advanced processing capabilities that can very rapidly alter their signal patterns, energy levels and even frequency bands. This means that not only are they more difficult to detect within the background “noise” of any battlespace, but they are also difficult to identify from their emission signature and can rapidly adapt their signal to reduce the ability of EW to degrade their effectiveness. Consequently, mission data for aircraft, defensive aid suites, weapon seekers and EW systems must be updated far more rapidly than ever before to remain effective in any conflict involving a major power like Russia.

Faced with the challenge of Russia’s extensive integrated air defence system, European air forces now face a requirement for much greater offensive stand-off and stand-in jamming capabilities to support SEAD/DEAD operations at scale

ML and AI technologies are likely to further increase the speed at which adversary systems adapt and change their behaviour in the coming years. However, these technologies also offer a path for the UK (and other NATO members) to greatly increase the speed and power of collection and mission data update cycles – especially by multiplying the capacity of relatively small teams of specialists. Therefore, the question of how to most efficiently and rapidly integrate advanced ML and AI capabilities into the JEWOSC in order to enhance its capacity and the speed at which it can generate new mission data should be a priority for the Ministry of Defence, even in a budgetary and strategic context where there are a huge variety of competing ones.

In February 2022, USAF F-35s found that even with the aircraft’s unmatched ELINT gathering sensor and analysis capabilities as a SEAD asset, some Russian radars were able to evade accurate identification by using previously unseen “war reserve modes”. The pace of Russian EW and radar signal adaptation has increased many times since then thanks to the pressure of the conflict against Ukraine. Without the capacity to update airborne mission data at a comparable pace, the UK will not only miss the opportunity to develop effective airborne EW capabilities that can help improve NATO’s SEAD/DEAD capabilities and thus its deterrence posture, but it will also risk seeing its existing combat air fleets lose survivability and lethality against Russia and other state threats over time.

Justin Bronk is the Senior Research Fellow for Airpower and Technology in the Military Sciences team at RUSI, and the Editor of the RUSI Defence Systems online journal. His particular areas of expertise include the modern combat air environment, Russian and Chinese ground-based air defences and fast jet capabilities, the air war during the Russian invasion of Ukraine, unmanned combat aerial vehicles and novel weapons technology.