‘Don’t shoot till you see the glint of their electro-optic sensors‘
Armoured fighting vehicle (AFV) designers employ a multilayered systems approach to protect AFV from threats in combat. This systems-of-systems configuration is referred to as the Survivability Onion. Layers of the onion include: don’t be seen, don’t be hit, don’t be penetrated and don’t be killed. Each onion stratum features specific technologies to safeguard an AFV and its crew. However, AFV survivability is not just the sum of discrete defensive systems, but rather it is their collective integration that generates superior protection.
Combat survivability effects in complex urban terrain are amplified when AFV defensive aides are used in parallel with combined arms tactics and AFV combat drills.
Infantry-armour cooperation is an indispensable pairing in complex terrain, as without infantry support armour is vulnerable to ambush. Armour mobility is hindered by rubble strewn streets in urban war zones that constrain freedom of manoeuvre and speed. Similarly, infantry are at risk from heavy weapons without the firepower that armoured vehicles provide. This symbiotic grouping is best practice, but with emerging anti-tank (AT) drone threats, Combat Teams  will need tailored anti-drone systems for the survival taxonomy to prevail in future war.
Arrival of autonomous anti-armour drones will be analogous to AT-3 Sagger missiles used to devastating effect against Israeli tank forces in the 1973 Yom Kippur War.
The tank warfare rulebook altered with the advent of anti-tank missiles, which outranged tank guns and easily penetrated passive armour. Since 1973 a litany of new technologies has evolved to mitigate AT missile threats. This Yom Kippur Effect will be pertinent again as anti-armour drones proliferate and become increasingly more capable. So it’s notable that major allies are already moving to restore the tactical balance  that smart drones could destabilize. Thus the following Acts are intended to highlight how this situation might unfold for combat forces.
Anti-Tank Drone Ambush Act 1 – Autonomous Tank Hunters
A Combat Team equipped with Infantry Fighting Vehicles (IFV) and tanks advance through shattered streets in a regional city. The Combat Team is tasked with flank security for its parent Battlegroup. A lead platoon employs drones to scout ahead, but they fail to detect six AT drones rising from roof holes on their left flank. The AT drones suddenly fire a volley of rockets with shaped-charge warheads  at the lead tank, triggering its Active Defensive Aide Suite (ADAS).
Drone launched AT rockets are intercepted and destroyed by hard-kill ADAS counter-measures, while the smart drones quickly reposition to fire a second volley of rockets.
ADAS radar automatically updates the tanks fire control and transmits this to the weapons integrated battle-management system in the trailing IFVs. The tanks turret elevates while traversing to the left and its coaxial machine-gun (MG) engages the nearest drone. Another drone is smashed by Remote Weapon Station (RWS) MG fire directed by the experienced tank commander. As the tank responds an IFV also attempts to engage a nearby AT drone with coaxial MG fire.
AT drones separate and present as fleeting aerial targets by vectoring unpredictably. AFV turrets cannot elevate high enough or traverse fast enough to target them all, so only two of the six attack drones are destroyed by manually targeted MG fire.
This initial rocket attack proves to be a diversion as a dozen quad-copter drones configured with Explosively Formed Penetrator (EFP) munitions track at high-speed on the Combat Teams right flank. While the lead tank and IFV are distracted by AT drone attacks on the left flank, dismounted infantry on the right identify the incoming EFP drone swarm and immediately begin engaging them with massed small arms fire.
Smart drones precisely coordinate offensive action in the autonomous anti-tank ambush. The assault is sudden, violent and leverages urban terrain to its advantage.
EFP drones conduct evasive flight manoeuvres and are also tough to knockout. At 200 metres none are shot down, but as they close to within 100 metres half of them are wrecked. Then by 50 metres two EFP drones remain, but they reach optimum stand-off distance and detonate. Hot metal slugs vector at well over 2500 metres per second, which is too fast for the ADAS to stop. Consequently, the tanks composite laminate armour is hydrodynamically  penetrated near its rear drive sprocket.
Tank crew evacuate their stricken vehicle as thick smoke billows from the engine bay. A multi-million dollar advanced combat vehicle is destroyed by a low-cost smart drone.
The unsuccessful counter-drone battle reveals another weakness in the Combat Team: single-barrel MGs that require barrel changes after firing 200+ rounds and small arms fire is insufficient to decisively defeat rapidly moving and evasive drone swarms. Manually operated weapons are largely ineffective beyond 200 metres against small fast drones that are trying very hard not to be hit. New tactics and technologies are now necessary.
Shades of Grozny – Lethal Drone Ambush
While the preceding scenario illuminates how the rise of AT drones might impact at the Combat Team level, this developing threat could occur on a far larger scale in the next decade+. Imagine hundreds of anti-armour drones launching coordinated autonomous assaults on a combat formation, which hasn’t been configured or trained to defend against swarms of weaponised smart drones.
Without counter-drone systems and tactics, the consequences of drone ambushes may rival or exceed vehicle casualty rates seen in the of Battle of Grozny.
In 1994-95 entire Russian armoured columns were decimated by Chechen forces firing anti-armour weapons from multiple elevations and angles. AFV turrets were unable to elevate weapons to engage rebels in tall multi-story buildings or suppress multiple threats simultaneously. Perched in positions of advantage in the City of Grozny, rebels overwhelmed AFV crews by targeting armour where it is most vulnerable; top, flanks and the rear.
Smart drone attacks on armoured forces will be similar to deadly Chechen 3D anti-armour ambushes in Grozny, only they will be an order of magnitude more lethal.
Chechen MG teams also pinned down supporting Russian infantry, while anti-armour teams coordinated deadly AT fires from above and on all sides of the armoured columns. Russian forces were forced to modify combat tactics due to heavy losses. So it seems plausible that anti-personnel drones might also accompany future AT drone attacks to further peel back the survivability onion and disrupt infantry-armour teamwork.
Anti-Tank Drone Ambush Act 2 – Automated Drone Destroyers
As the AT drones spring their complex autonomous ambush, an Automated Drone Defence (ADD) AFV supports the lead tank caught in the ambush kill zone. ADD AFV target acquisition radar locks-on each drone and sequentially obliterates them in seconds with short well-aimed bursts of fire from an M61 20mm Vulcan Cannon. The anti-drone cannon is a Gatling gun-style, six-barrel weapon that was previously used in military aircraft and air defence roles. However, in this Act the M61 was mounted in an AFV and optimised as a high-angle anti-drone variant for close combat.
An automated radar-cannon combination provides Combat Teams with a ‘Land Phalanx’ capability, which swiftly targets and destroys multiple smart drones at range.
As the last AT drone crashes, dismounted infantry on the right flank alert IFV and tank crews to the incoming horde of EFP drones. A similar outcome ensues as the Vulcan Cannon spins up and unleashes measured bursts of accurate 20mm rounds down the street. Infantry observe the spectacle unfold as the Vulcan efficiently dismantles the cloud of hostile bots. Hapless EFP drones try to evade ruthless cannon fire, but attempts are futile due to the weapons precision target tracking.
The counter-drone ambush engagement is over in four minutes and the flying EFPs lie in ruins approximately 200 meters away from Combat Team’s forward elements.
Anti-Tank Drone Ambush Final Act – Drone Defence Variants
Act 1 highlights how current weapon systems are not optimised for future smart drone threats, which could feature a myriad of anti-tank capabilities that fly autonomously. Static EFPs constitute an existential threat to armoured vehicles.The prospect of these AFV killers merging with agile smart drones and coordinating via neural networks will require bespoke counter-measures and battle drills to respond. Moreover, Act 1 illustrates how drone algorithms will be programmed to deceive ground forces, and like human combatants will use features of terrain to their tactical advantage.
Act 2 demonstrates how a dedicated drone defence AFV with an automated fire control system and a weapon capable of huge volumes of rapid fire may be a vital inclusion in future classes of combat vehicle, as drone threats are forecast to grow exponentially.
In addition to kinetic counter-measures, other anti-drone technologies are being developed, such as electromagnetic disrupters and directed energy weapons. These technologies may compensate for the limited effectiveness of conventional small arms against autonomous drone swarms. Tethered Anti-Drone Drones could also be deployed and recovered from AFVs to provide security and rapid response against menacing drones. Mobile hard-kill and soft-kill drone attack mechanisms will be increasingly necessary in the coming years.
AFV security drones may be a key feature of close combat in future war. Hard-Kill and Soft-Kill defence measures will evolve beyond systems physically interfaced on AFVs.
Until drone close defence systems are mature, Combat Teams must adapt current defensive procedures. Drone defence tactics will become a lexicon in its own right. So battle shooting training for AFV crews to neutralise moving drone threats, will build confidence and serve as essential combat risk mitigation. As discussed, in the initial ‘Defence Against the Drone Arts’ article, light infantry will be hard-pressed to defeat drone swarms with small arms fire and current tactics, so this emerging close combat challenge also applies to extant AFV weapon systems and battle drills.
The famous battle cry at Bunker Hill in 1775 ‘don’t shoot till you see the whites of their eyes’ resonates in context of futile efforts to shoot down swift drones in urban terrain.
In Act 1, EFP drones at range evaded small arms fire and finite ammunition was squandered. As flying drones closed with infantry their numbers gradually depleted, as they were an easier target. It may be that holding weapons fire until the moment it will have greatest effect will be vital against smart drone swarms. Fire discipline at close ranges will preserve ammunition and avoid MG barrel changes at a precarious time, as drones will vigorously manoeuvre to limit battle damage. Hence, centuries old fire control orders find new relevance for future urban warfare, as not shooting till you ‘see the glint of electro-optic sensors’ may be a useful rule-of-thumb in close counter-drone battles.
By: LTCOL Greg Rowlands
About the Author:
Lieutenant Colonel Greg Rowlands is an infantry officer with 27 years of Army experience. He has served in mechanised infantry and light infantry units, including as a combat tactics instructor at the US Army Infantry School. Greg has trained on the Warrior Infantry Fighting Vehicle at the UK School of Infantry and served with a British armoured infantry unit in the Former Yugoslavia.
1 Combat Teams have other support elements, such as but not limited to, combat engineers, aviation and joint fires teams to coordinate offensive support. These enablers will not be immune to the disruption of hostile combat drones.
2 The US Army is developing anti-drone armoured vehicles and the US Marine Corps are establishing drone operators down to squad level. These capability and force structure changes are instructive and indicative of future drone threats.
3 This is applicable to logistics forces, which will also be at risk from weaponised enemy drones operating in rear areas, attacking distribution points, resupply convoys and logistics hubs. Drones will not only be a close combat problem.
4 High Explosive Anti-Tank (HEAT) munitions feature a warhead that consists of an explosive charge and a metal liner that when triggered forms a shaped-charge molten metal jet from compressive detonation waves. It requires a precise stand-off distance to enable the optimum super-heated jet to form, so the round has a characteristic ‘spigot’ attached to it. More lethal variants of anti-tank munitions feature a tandem warhead designed to defeat explosive reactive armour.
5 EFPs are similar to shaped-charge HEAT warheads, however the metal liner is engineered differently. Altered munitions geometry prevents a hot jet from developing and instead a metal ‘slug’ is formed that reaches hyper-velocity. However, EFPs are insensitive to short stand-off distances that HEAT warheads require.
6 Hydrodynamic armour penetration occurs when a hyper-velocity projectile strikes target armour material. The penetrator and target material behave similar to fluid motion. Penetration mechanics occur due to shock pressures generated on impact that are orders of magnitude higher than armour material yield strengths.
7 Troops will need to become comfortable operating in a drone-threat environment. Hence developing bespoke counter-drone tactics, training activities and technologies will be an important step forward for 5th Generation Armies.
8 The M61 Vulcan Cannon has been previously mounted in an M113 Armoured Personnel Carrier chassis (designated M163) and employed in an anti-aircraft role by the US and other countries. So while the M61 Vulcan may prove to not be the best weapon for close drone defence, this type of weapon system is illustrative of rapid automated targeting and high volumes of accurate fire that may be necessary to counter smart drone swarms in future drone warfare.
9 IFV auto-cannons and chain guns may also have limited effectiveness against multiple small fast moving drone targets. This could be offset by proximity airburst munitions at range, but will be a high risk proposition when drones are on short-finals and approaching dismounted infantry security elements. Munitions safety distances will be a factor.