How Cheap And Effective Loitering Munitions Are Relevant To India’s Defence Strategy

Ukraine war has once again brought focus to the loitering munitions, also known as the Kamikaze or suicide drones. The munitions are designed to arrive as the air defence radars that remain silent and transmit selectively for short in the general target area, wait passively, look for the target, identify and then attack. Loitering munitions allow faster response against concealed or hidden targets that emerge for short periods, among many others. The much less expensive drones are preferred over exposing high-value platforms such as fighters close to the target area. The drone attack can easily be aborted and the drone can be repositioned in loiter mode. Loitering munitions fit perfectly in the space between cruise missiles and unmanned combat aerial vehicles (UCAVs), and use the combat employment characteristics of both. The cruise missiles cannot loiter. The UCAVs can loiter but don’t have an inbuilt warhead and deliver weapons like aircraft.

Loitering weapons first evolved in the 1980s for use in the Suppression of Enemy Air Defences (SEAD) role against surface-to-air missiles (SAM), and were deployed for the SEAD role in a number of military forces in the 1990s. Starting in the 2000s, loitering weapons have been developed for additional roles ranging from relatively long-range strikes and fire support, and down to tactical, very short range battlefield systems that fit in a backpack.

Earlier they have been used in Afghanistan, Syria, and Yemen, but only in the 2020 Nagorno-Karabakh War, they came in the limelight in a contested environment for the first time. The videos going viral of direct hits on tanks and other ground vehicles indicate tactical successes. However to draw correct lessons, there is a need to understand the technology and employment dynamics.

When the SAM combined with radars began to be used extensively, it became a deadly threat for jet combat aircraft. The loitering munitions were then evolved. With the pilot out, human risk got reduced. The flight time of the flying platform could now be expanded. The in-build warhead was introduced. The munitions were thus expendable and relatively cheaper. They could now search for both known and unknown missile installations. The loitering munitions could be used stand-alone or in combination with a fighter raid.

Israeli Delilah variants came up in the early 1980s. In late 1980s IAI Harpy was the first loitering munitions widely exported, and also bought by the Indian Air Force (IAF). The Americans had the AGM-136 Tacit Rainbow which was often termed more as a UAV. They were used for SEAD roles against SAMs, and were deployed in a number of military forces by the 1990s. Starting in the 2000s, loitering weapons have been developed for additional roles ranging from relatively long-range strikes. Israel Aircraft Industry (IAI) Harop was one such system.

Later were developed smaller, tactical fire support, very short range, battlefield systems that could fit in a backpack. They could fly, loiter, search and identify a target using their own sensor, hit a target like a missile, and were expendable. The sensors could be radar, thermal imaging, or visual sensor data. Loitering munitions could be as small as a model airplane or a little longer. Typically fixed-wing, and powered by pusher propellers, they could resemble everything from matchsticks with wings to a large bird of prey.

Artificial intelligence, combined with developments in communications technology, computing, processing, and miniaturised sensors means that loitering munitions can now be autonomous and serve a range of functions in war. Alternatively there could be a human in the loop. Earlier loitering munitions were used to target radars, but are increasingly being used to attack tanks, combat assets, vehicles and even humans.

They are mostly one-time-use expendables. The target search could be autonomous, using its own airborne sensors or by a human in the loop. More advanced and expensive drones could be recalled or recovered in case not used. There are some loitering munitions that can land inert and then be refuelled for future flights. The loitering munitions could be launched from a ground station, an airborne platform, or as a small discreet, man-portable weapon. Large ones, like the IAI Harop operated by IAF could loiter for 8-9 hours. Small ones as used in Ukraine could loiter for 30-60 minutes.

While cruise missiles, such as the block IV Tomahawk, have the ability to loiter and have some sensory and remote control features, but cruise missiles primary mission is typically a pre-designated strike. Cruise missiles are optimised for long-range flight at constant speed. Weapons carrying UAVs (UCAV) return back to land. UCAVs are noisy, often costly, and can’t be expended. Loitering Munitions are optimised with very short engine life, silent strike phase, and speed during final dive, and are cheaper.

Ukraine has become a testing ground for loitering munitions. Ukraine manufactures two types of drones. Ukrainian catapult-launched RAM II, is comparable in capabilities to the Switchblade 600. It has anti-armour and thermobaric warhead options. With a 40-minute flight time, 30 kilometres range, it can be handled by a single operator. The ST-35 Silent Thunder, is a multi-rotor vertical launch and horizontal flight type with longer flight duration. Ukraine also uses imported drones such as Polish Warmate kamikaze drones. The Bober, the UJ-22 Airborne and some other drones have been used to hit targets in Russia, including Moscow. The number of kamikaze drones that struck Russia between May and July 2023 was double for all of 2022.

The US has sent very large numbers of AeroVironment Switchblades to Ukraine. The smaller man-portable variant (2.5 kilograms) with 10 kilometre range costs just $6,000, and is good for soft skin vehicles. The heavier (25 kilograms) with 40 kilometre range, can pierce tank armour. The US has also committed Puma reconnaissance drones, counter-drone systems, and naval drones to Ukraine, as well as the ‘Phoenix Ghost Tactical Unmanned Aerial System’.

Russian manufacturer Zala-Aero Group’s “Lancet” loitering munitions, was successfully in Syria in 2021. With loiter time of 40 minutes and range around 40 kilometres, Russia is employing them to support maneuver and siege operations. The Lancet can autonomously locate and strike targets. Russia’s second loitering munition has been the KYB. With an operator in the loop, it is for fixed site targets. These small payload munitions were created for counter insurgencies. Russia has received hundreds of Iranian drones Shahed-136 (renamed Geran-2), and Shahed-131 (Geran-1), and the Mohajer-6 multirole UAVs.

Loitering munitions are making a significant cost effective impact on war. Top attack on tanks, convoys, mobile-command posts or even fuel dumps and similar other targets are seeing devastating effects and some of these may require reengineering. They are supplementing air strikes, anti-tank weapons, and long-range artillery. In fact, they have begun questioning the invincibility of the battle tank. Loitering munitions attacking a ship or aircraft parked in the open can cause severe damage. Being much smaller, they are difficult to locate or be targeted. They are thus important elements of the multi-domain operations, and need to be factored by military planners and the doctrines.

Loitering munitions are now integrated into the greater strategy of the war. For countries that cannot afford stealth aircraft, the ability to take out anti-air missile batteries with expendable radar-seeking drones is powerful and more affordable. Once loitering munitions remove anti-air defences, then fighter attack aircraft can take-on other heavy targets with relative impunity. A modest technological advantage can be turned into a major strategic benefit. Unlike land and sea mines, loitering munitions have no humanitarian angles to contend.

Finite flight time is the first limitation. The accuracy of attack is dependent on the sensors, and they could have errors or be degraded by enemy action or jamming. Weather affects optical systems. The positions can change in a dynamic battle. The on-board computers or GPS could be jammed or fooled, and the adversary could divert it away and crash, or worse go back and attack the launch point. Autonomy is vital to loitering munitions. Any regulatory regime that governs autonomy will profoundly impact loitering weapons in the future. Thousands of loitering munition drones have been neutralised in the Ukraine conflict. Counter to drones include hard and soft kill methods. The USA has tested airborne microwave weapon’s ability to defeat kamikaze drones. Lockheed Martin’s MORFIUS system can fly close to small drones and attack them with high-powered microwave pulses.

Many countries are already manufacturing loitering munitions. These include China, Israel, Iran, Russia, Taiwan, Turkey, and the United States. Countries like Azerbaijan, Germany, and South Korea have bought them from the major manufacturers. India has a huge start-up ecosystem and is trying to make its own.

China operates IAI Harpy, but also has its own CH-901, WS-43, and ASN-301 loitering munitions. PLA Army and PLA Air Force (PLAAF) are investing in, and developing loitering munitions. They showcased some at the Thailand Defence and Security exhibition in August 2022. The FH901 weighs 9 kg, with a 3.5 kg warhead, and is equipped with an electro-optical and infrared gimballed seeker. It is canister-launched and reportedly has flight-time of 60 minutes at 100-150 kmph. The FH901 executes a terminal dive like the Harop at 288 km/h.

The major loitering munitions in the United States are AeroVironment Switchblade, Phoenix Ghost, Raytheon Coyote, HERO 120, Point Blank, ALTIUS-600M. Raytheon Edge 21 received a major order.

India already operates or is working on loiter munitions such as IAI Harpy, IAI Harop, SkyStriker, Warmate, Trinetra, Nagastra series, and ALS-50, Sierra Tango loitering munitions. Many start-ups and public sector companies in India are entering into loitering munitions design and production. It is possible to modify the existing drones into loitering munitions. The cost and size make it possible to scale these for smaller military formations. Grenades can also be slung beneath a quad-copter with cameras to make attacks on forces behind cover. Indian Army has procured 100 x Warmate micro loitering munitions from Poland. India’s indigenous loitering munitions are being built by DRDO. Also a private sector company EEL, a subsidiary of Solar Group makes Nagastra 1 (1.5 kg payload) and 15 km. Nagastra 2 with 4 kg warhead and 25 km range has also been tested successfully. Nagastra 3 with a 15 kg warhead and 100 km range is under development. The IAF has inducted the unique vertical take-off and landing (VTOL) capability, ALS-50, loitering munitions developed by Tata Advanced Systems. It allows it to engage forward radars and air defence systems, assets on frontier airfields, and ground and naval targets. Z motion of Bangalore has made Trinetra precision guided hand launched tactical attack UAV. India has already inducted Elbit Systems SkyStriker tactical loitering munitions for covert and precise airstrikes.

Loitering munitions have already revolutionised the battlefield in recent years and more of these can be expected to fill up the airspace in future. They will be a cost effective force multiplying game-changer. India’s private sector is well equipped to develop these as a part of the drone culture and revolution already under way in India. Some critical components of the loitering munitions are still not manufactured in India. These are already in the cross-hairs of Drone Federation of India, which has galvanised the manufacturers to develop indigenous technologies. Indigenous loitering munitions, capable of operating from difficult terrain and high altitude areas, have already been demonstrated with strike roles at Pokhran firing range. Made-in-India loitering munitions are expected to be at least 40 per cent cheaper than imports from Israel and Poland. India must go whole hog into loitering munitions. Time to act is now, lest we get left behind.