Contemporary conflicts demonstrate the rapid proliferation of one-way attack drones (OWAD), which have been deployed at scale in the war in Ukraine and the US-Israel-Iran conflict. In both theatres, each side has resorted to mass use of OWADs to saturate a targeted state’s ground-based air defences (GBAD). This strategy inflicts near-constant pressure on an adversary’s military and civilian infrastructure, while systematically wearing down their political will.
To address the emergent OWAD threat, states are seeking affordable and scalable defences. This article begins a series of RSDI Insights examining specific aspects of counter-OWAD (C-OWAD) defences, starting with an assessment of the airborne leg.
Aircraft in a C-OWAD role
Aircraft, both fixed- and rotary-wing, offer obvious advantages over ground-based defences. They offer speed and flexibility of response; alert aircraft can be scrambled to intercept incoming threats, or they can establish combat air patrols (CAP) over wide geographic areas covering likely directions of attack.
Aircraft provide a measure of defence in depth by deploying well outside the protective layers of GBAD systems, thinning out incoming mass OWAD salvos before they reach the effective fire envelope of the various ground-based defences.
Moreover, airborne early-warning and control aircraft (AEW&C) can provide improved early warning against OWADs over ground-based radars, with a significantly longer detection range against low- and slow-flying targets, thanks to their excellent look-down capability.
AEW&C aircraft can act as local area battle-managers, directing CAP aircraft to engage oncoming OWADs. During the US-Israel-Iran conflict, the Royal Australian Air Force deployed an E-7A Wedgetail AEW&C to the Gulf to help partner states repel Iranian Shahed and cruise missile attacks.
To respond to the OWAD threat, air forces are repurposing existing aircraft, including trainers, helicopters, and fighter jets, as makeshift OWAD defences. For example, the Ukrainian Air Force assigns a large portion of its Soviet-era MiG-29 and Western-donated F-16 fleets to a C-OWAD role. Similarly, the UAE extensively employed its own F-16s and AH-64 attack helicopters to hunt down Iranian Shahed drones in February-July.
The Cost and Strain of Using Combat Aircraft
However, the unexpectedly high sortie requirements are taking a toll on small fighter fleets, consuming exorbitant numbers of flight hours and putting pressure on maintenance. In addition, using primary combat aircraft in a C-OWAD role reduces crucial mass that could be deployed in other critical roles like offensive counter air, air interdiction, and conventional strategic strike.
Moreover, air forces continue to rely primarily on existing armament, which consists of short- and medium-range air-to-air missiles (AAM) like the ubiquitous AIM-9 Sidewinder and AIM-120 AMRAAM-family missiles, and the internal gun. These weapons come at a relatively high cost, from US$80,000 for an AIM-9M, US$500,000 for the more modern AIM-9X-2, to US$1.3 million for an AIM-120C-7. In contrast, a Shahed-136 or Geran-2 OWAD costs only between US$30,000 and US$80,000 per unit.
Besides the cost asymmetry, existing AAMs are designed for air-to-air engagements between combat aircraft, and the sudden demand to repel mass OWAD attacks is rapidly depleting existing missile stocks. As a result, air forces have resorted to the more sustainable practice of using the internal gun to down OWADs.
Critically, the C-OWAD burden on air forces will likely increase in the short term as actors increasingly employ jet-powered OWADs like the Russian Geran-4 and Geran-5, or the Iranian Shahed-238. Jet-powered OWADs are generally two to three times faster than their pusher-propeller counterparts and fly at higher altitudes, putting them above most short-range, low-altitude air defence systems’ effective engagement envelopes.
This has dramatically reduced mass in Ukraine’s effective air defence against the OWAD threat. Addressing the evolving threat demands more defensive counter-air sorties from an already stretched fighter fleet.
New Trendlines: Scale and Affordability
The good news is that C-OWAD is rapidly adapting to the threat, and industry and militaries alike are actively proposing new solutions.
One of the critical early solutions was the adaptation of existing air-launched 70mm semi-active laser-guided rockets – the BAE Systems AGR-20F Advanced Precision Kill Weapon System-II (APKWS-II) and the Thales FZ123 – into affordable anti-drone rockets.
These popular weapons are fitted with a semi-active laser-seeker head, which receives laser tracking from the host aircraft’s targeting pod or an EO/IR turret, with proximity fuses to enhance probability of kill (Pk) against drones.
Moreover, to relieve the launch platform of continuously lasing the target, an imaging infrared (IIR) seeker-head will replace the laser-seeker in the next evolution of air-to-air rockets (AAR). The IIR seeker-head provides a true fire-and-forget capability.
Importantly, AARs cost significantly less than contemporary AAMs. For instance, the AGR-20F costs only US$22,000-35,000 per unit. AARs do not merely beat most OWADs on cost; they also offer scale. They are carried in pods holding between 7 and 12 rockets, significantly increasing magazine depth. While an F-16 could carry up to six traditional AAMs to a fight, the same aircraft can now carry up to 42-48 AARs. Consequently, a single four-ship CAP can theoretically engage up to 168-192 OWADs during a single mission.
Aircraft manufacturers now offer air forces light combat versions of existing turboprop and jet trainers that can act as cost-effective C-OWAD platforms. For example, Embraer’s A-29 Super Tucano turboprop trainer or Textron’s missionised AT-6 Wolverine II can use their existing EO/IR and laser-tracking turrets to search for and designate targets, or receive target information through a datalink, and employ AARs, gun pods, or integrated machine guns to engage OWADs.
Choosing the Right Platform Against Jet-Powered OWADs
However, jet-powered OWADs cruising at 500-600 km/h, such as Shahed-238 and Geran-4/5, are challenging the utility of turboprop aircraft in OWAD defence, as the top speed of these aircraft is similar to that of the OWADs.
Manufacturers such as Leonardo (M-346), KAI (TA-/FA-50) or Aero Vodochody (L-39NG) offer their jet-powered advanced trainers and light combat aircraft as cost-effective C-OWAD defence options. The M-346 and FA-50 are fitted with modern active electronically scanned array (AESA) radars, targeting pods, and datalinks, alongside AARs and gun pods to turn the jet-trainers into effective C-OWAD platforms.
Critically, light combat aircraft sit between the turboprop trainers and high-end combat aircraft, offering better operating economies than the latter, while retaining substantial performance advantage over the former.
However, Poland, Ukraine, and Latvia still deem the light fighter option too costly for the C-OWAD mission, favouring a turboprop option; all three are studying Embraer’s Super Tucano instead. In contrast, Austria’s recent decision to acquire the M-346F cited the need to use the platform in both training and C-OWAD roles.
Moreover, air forces may use ageing aircraft types that are reaching the end of their effective combat utility in a C-OWAD role. For example, the US Marine Corps’ legacy F/A-18C/D Hornet fleet, which is edging towards retirement by 2030, is equipped with the AGR-20F AAR to act as a C-OWAD platform. This has helped release the Marines’ new F-35 fleet for more demanding missions.
Similarly, the US Air Force has famously employed its F-15E Strike Eagle and F-16C fleets in this way. On 13-14 April 2024, Strike Eagles, each armed with up to six AGR-20F pods and forward deployed to the US Central Command area of operations, flew countless defensive counter-air sorties to repel massive Iranian OWAD and cruise missile attacks against Israel, reportedly downing more than 80 OWADs in the process.
Airborne Defence as One Layer of Air Defence
Critically, as the real-world experience has demonstrated, airborne OWAD defence is an essential part of a layered air defence system. It offers defence in depth by operating combat aircraft between the point-air defence layers and high-end fighters, thinning incoming mass OWAD salvos and reducing the pressure on various ground-based defences.
However, the emergence of jet-powered OWADs places additional demand on airborne C-OWAD, at least in the short term, while other technological adaptations, such as low-cost interceptors, interceptor drones, specialised active and passive sensors, and, importantly, more suitable aircraft are reaching service around the world.
