Indian Defence Review

Drones can be aerial improvised explosive device delivery platforms in present-day theatres of combat 

Since the US invasion of Iraq over a decade ago, the use of improvised explosive devices (IEDs) has seen extraordinary success as a cheap and effective weapon sourced from locally available materials such as diesel fuel and ammonium nitrate fertilizer against ground forces in asymmetric and urban combat.

The United States government’s decision early in the 2nd Iraq War to up-armour part of its fleet of Humvee tactical vehicles to improve survival against buried explosives is a tacit acknowledgement of the brutal efficacy of IEDs.

The menace of IEDs is a threat faced daily by the Indian Army and paramilitary forces during daily road-opening operations in Jammu and Kashmir, some states of the North East and Maoist-afflicted parts of Chhattisgarh, Orissa, West Bengal and Telangana. Mine protected vehicles, which have been procured for use by police in Jharkhand and by the Indian Army, are a testament to the perceived threat from IEDs.

Data analysis reveals that IEDs cause a large and increasing proportion of casualties among NATO and American troops in Iraq and Afghanistan. This trend has increased year on year. Aerially deployed IEDs represent a challenging yet underestimated threat to armed forces in this era of increasingly asymmetric warfare. This article highlights a new and emerging threat of “aerial IEDs” when they are deployed on commercially available drones and discusses possible strategies to counter this threat.

Military versus commercial drones:

Drones have traditionally been owned and operated by government forces in combat zones for aerial surveillance. While weaponized drones have been used with success by very few militaries to achieve strikes on distant targets, smaller commercially available drones such as quadcopters have recently been utilized in passive roles in conflict zones such as the Ukraine by both conventional forces and militias for aerial surveillance.

However, the recent death of two Kurdish Peshmerga fighters in the Middle East highlights an evolving new trend in the form of weaponized commercially available drones operated by insurgents to inflict casualties, effectively turning drones into airborne IED delivery platforms.

Many off-the-shelf drones such as the Parrot already have high-definition cameras. Newer models with sustained airborne time are being designed to carry commercial cargo. These are especially likely to be misused to carry and deliver explosive payloads. Armed drones developed from commercially available models are much cheaper than military-specific models.

A fundamental difference of use between military and civil drones is that military drones are expensive and flown back at the completion of a mission by trained operators whereas armed insurgents using modified drones are likely to destroy the delivery system along with the IEDs that they carry, in effect turning their improvised drones into “unmanned airborne fidayeen”. Even unarmed drones can be used by terror groups for valuable aerial reconnaissance, thereby necessitating a paradigm shift in the definition of “perimeter security” of military bases in areas close to our national borders.

The evolving threat of commercially available drones:

As drone technology improves with advances in battery technology and more efficient (and agile) flight characteristics, the ability to carry heavier payloads for longer durations will improve. Satellite-guided navigation may remain the purview of military-operated drones for some time but autonomous guidance systems with or without Global Positioning System (GPS) support will reduce the skill level required of drone operators.

“Swarms” of autonomous miniature drones flown into an air force or army base by militants may lack weaponized payloads but could, in theory, be pre-programmed to disable assets such as combat or transport aircraft by targeting engine air intakes or propeller blades of taxiing fixed-wing and rotary-wing aircraft.

Similarly, an unarmed drone can be sufficiently distracting to armed guards at the gates of a military base to facilitate a covert conventional strike. Just as 5.56 mm rifle rounds wound rather than kill and thereby disrupt the enemy’s forces, attention and morale, a few drones detonating small charges of C4 explosive while airborne can be distracting even if not lethal.

Future threats:

Apart from passive imaging for reconnaissance, weaponization of drones is not necessarily limited to delivery of lethal explosives. A drone carrying a low-grade radioactive cargo can be detonated aerially as a “dirty bomb” and constitute a formidable psychological threat. This fear-inducing tactic is not new and was utilized effectively by Japan as kamikaze aircraft and Shinyo suicide boats against Allied vessels in the Second World War. Biological weapons such as anthrax can be dispersed by modifying drones designed for crop dusting. Chemical weapons such as VX, used most notably in the recent attack in a Malaysian airport, can be disruptive more from psychological fear than actual kills.

Drone-defeating strategies:

Commercially available drones weaponized for inflicting casualties are unlikely to be a game changer by themselves in warfare; however, they do constitute a potent psychological weapon when deployed in asymmetric combat.

It is imperative for India to realize the threat of weaponized commercially available drones and formulate a drone-defeating doctrine before commercial drone technology becomes sophisticated and harder to intercept.

While larger unmanned aerial vehicles (UAVs) can be detected by radar and targeted, small drones are nearly invisible to conventional radar or may fly too low for detection. The resultant constant manual vigilance required can be fatiguing. Technology to take down drones can be expensive, of limited effectiveness and take many years to develop given our track record of decades spent in developing weapon systems.

The practicality of electronic signal jamming to down drones will have to be studied in view of an increasingly electronic future battlefield. However, since increasingly autonomous systems can be preprogrammed to reach a destination or fly and return independently, signal jamming may be rendered redundant as a means of disabling drones.

Shooting down hovering drones has been done but will become near impossible as drones become smaller, more agile and adopt non-linear flight paths with autonomous guidance. Biological systems may offer an interesting, cost-effective and viable solution to counter the threat of rogue drones.

Explosive detection has traditionally relied on trained dog breeds such as Labradors and German Shepherds for their intelligence as well as sensitive and specific olfactory abilities; Belgian Malinois are intelligent, agile and hardy enough to be trained as assault dogs. It may be worth exploring the use of trained birds-of-prey such as falcons as “drone killers”. Unlike technological solutions, a biological drone-defeating system can be developed and tested in less than one year.

Conclusion:

Improved technology to detect and disable conventional buried IEDs and lessons learnt from experience have led to fewer fatalities and casualties among army and paramilitary forces. Research in battery technology for smartphones and electric vehicles receives massive funding annually. It is fairly safe to predict that newer generations of battery technology and improvements in artificial intelligence will lead to a quantum leap in the navigational characteristics, autonomy and load-carrying abilities of commercial drones as well as major improvements in flight time.

Legislation to restrict sales of drones will be meaningless unless the radiofrequency spectrum utilized in drone operation is tightly controlled akin to that of satellite phones. Even then, autonomous flight systems will make signal jamming redundant. The Army Aviation Corps and Army Air Defence Corps needs to develop strategies to take on the evolving unconventional threat of weaponized and surveillance civilian drones.

DRDO must work in tandem with stakeholders the army and paramilitary forces to develop drone-defeating technologies. Till then, the Remount and Veterinary Corps must experiment with tackling drone threats by with trained predator birds as drone killers.

The recovery of increasingly sophisticated technology such as GPS navigation devices, night vision devices, satellite phones, smartphones with encrypted messaging, voice over internet protocols (VoIP) for calling and tampered SIM cards from slain militants makes it almost inevitable that off-the-shelf drones for surveillance or attack will emerge in this decade as a challenge that Indian forces will have to deal with in future counter-insurgency and anti-Maoist operations.