The High Speed Low Drag (HSLD) bomb is a family of new generation short-range air-dropped

general-purpose bomb A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect. They are designed to be effective against enemy troops, vehicles, and buildings. Characteristics ...

that developed by India's

Defence Research and Development Organisation The Defence Research and Development Organisation (DRDO) is an agency under the Department of Defence Research and Development in the Ministry of Defence of the Government of India, charged with the military's research and development, head ...

(DRDO) for the

Indian Air Force The Indian Air Force (IAF) (ISO 15919, ISO: ) is the air force, air arm of the Indian Armed Forces. Its primary mission is to secure Indian airspace and to conduct aerial warfare during armed conflicts. It was officially established on 8 Octob ...

(IAF). It can can be used against the destruction of strategic high value enemy infrastructure from stand-off distances. The HSLD is comparable to the

Mark 80 A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect. They are designed to be effective against enemy troops, vehicles, and buildings. Characteristics ...

series bombs used by the

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

(USAF) and its allies. Multiple guidance kits, like PGHSLD and TARA REK, are also under development to convert these unguided bombs into

precision-guided munition A precision-guided munition (PGM), also called a smart weapon, smart munition, or smart bomb, is a type of weapon system that integrates advanced guidance and control systems, such as Global Positioning System, GPS, laser guidance, or Infrared ...

s. The guidance kit will use

semi-active laser Laser guidance directs a robotics system to a target position by means of a laser beam. The laser guidance of a robot is accomplished by projecting a laser light, image processing and communication to improve the accuracy of guidance. The key ide ...

electro-optical Electro–optics is a branch of electrical engineering, electronic engineering, materials science, and material physics involving components, electronic devices such as lasers, laser diodes, LEDs, waveguides, etc. which operate by the propaga ...

imaging infrared Infrared thermography (IRT), thermal video or thermal imaging, is a process where a thermal camera captures and creates an image of an object by using infrared radiation emitted from the object in a process, which are examples of infrared imag ...

seekers to assist in precision strikes.

Description

The

Armament Research and Development Establishment In India, the Armament Research & Development Establishment (ARDE) is a laboratory of the Defence Research and Development Organisation (DRDO). Located in Pune, it is the main DRDO lab involved in the development of conventional weapons, conve ...

(ARDE),

Pune Pune ( ; , ISO 15919, ISO: ), previously spelled in English as Poona (List of renamed Indian cities and states#Maharashtra, the official name until 1978), is a city in the state of Maharashtra in the Deccan Plateau, Deccan plateau in Western ...

is the primary agency that started developing HSLD with the help from other DRDO laboratories to upgrade the conventional free fall unguided ordnance used by the Indian Air force (IAF) fighter pilots while

Ordnance Factory Board The Directorate of Ordnance (Coordination & Services) (abbreviated: DOO(C&S)) is an authority under the Department of Defence Production (DDP) of Ministry of Defence (MoD), Government of India. Its primary work is to management, give instructio ...

(OFB) is the lead production agency. The development started with the aim to replace the older generation imported general purpose bombs that impose huge

drag Drag or The Drag may refer to: Places * Drag, Norway, a village in Tysfjord municipality, Nordland, Norway * ''Drág'', the Hungarian name for Dragu Commune in Sălaj County, Romania * Drag (Austin, Texas), the portion of Guadalupe Street a ...

loss on

fighter aircraft Fighter aircraft (early on also ''pursuit aircraft'') are military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air supremacy, air superiority of the battlespace. Domina ...

used by the IAF. The HSLD bomb is specially designed to productively use the higher speed of up to

Mach The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a Boundary (thermodynamic), boundary to the local speed of sound. It is named after the Austrian physi ...

1.1 and wider flight envelope of newer generation

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

and Russian origin as well as Indian made aircraft.

High Energy Materials Research Laboratory High Energy Materials Research Laboratory (HEMRL) is one of the premier laboratories of the Defence Research and Development Organisation (DRDO) located in Pune Maharashtra. Main area of works of the lab include research and development of high ...

(HEMRL) developed the conventional type warhead for the HSLD and GP bombs that features

blast Blast or The Blast may refer to: *Explosion, a rapid increase in volume and release of energy in an extreme manner *Detonation, an exothermic front accelerating through a medium that eventually drives a shock front *A planned explosion in a mine, ...

, fragmentation and

shaped charge A shaped charge, commonly also hollow charge if shaped with a cavity, is an explosive charge shaped to focus the effect of the explosive's energy. Different types of shaped charges are used for various purposes such as cutting and forming metal, ...

for

bunker buster A bunker buster is a type of munition that is designed to penetrate hardened targets or targets buried deep underground, such as military bunkers. Armor piercing shells Germany Röchling shells were bunker-busting artillery shells, developed ...

role. By feeding the target coordinates, the warhead can be used to effectively destroy

runway In aviation, a runway is an elongated, rectangular surface designed for the landing and takeoff of an aircraft. Runways may be a human-made surface (often asphalt concrete, asphalt, concrete, or a mixture of both) or a natural surface (sod, ...

railway track Railway track ( and UIC terminology) or railroad track (), also known as permanent way () or "P way" ( and Indian English), is the structure on a railway or railroad consisting of the rails, fasteners, sleepers ( railroad ties in American ...

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

, industrial facility,

dock The word dock () in American English refers to one or a group of human-made structures that are involved in the handling of boats or ships (usually on or near a shore). In British English, the term is not used the same way as in American Engl ...

and

bunker A bunker is a defensive military fortification designed to protect people and valued materials from falling bombs, artillery, or other attacks. Bunkers are almost always underground, in contrast to blockhouses which are mostly above ground. T ...

while able to work in the absence of

GNSS A satellite navigation or satnav system is a system that uses satellites to provide autonomous geopositioning. A satellite navigation system with global coverage is termed global navigation satellite system (GNSS). , four global systems are op ...

input due to satellite jamming. HSLD can be launched from variety of aircraft that are under IAF inventory like

Dassault Mirage 2000 The Dassault Mirage 2000 is a French multirole, single-engine, delta wing, fourth-generation jet fighter manufactured by Dassault Aviation. It was designed in the late 1970s as a lightweight fighter to replace the Mirage III for the French Air ...

SEPECAT Jaguar The SEPECAT Jaguar is a British-French supersonic jet attack aircraft originally used by the British Royal Air Force and the French Air Force in the close air support and nuclear strike role. As of 2025, the Jaguar remains in service with the ...

Sukhoi Su-30MKI The Sukhoi Su-30MKI (NATO reporting name: Flanker-H) is a two-seater, twinjet Multirole combat aircraft, multirole air superiority fighter developed by Russian aircraft manufacturer Sukhoi and built under licence by India's Hindustan Aeronautic ...

and

HAL Tejas The HAL Tejas () is an Indian single-engine, delta wing, Multirole combat aircraft, multirole Military aircraft, combat aircraft designed by the Aeronautical Development Agency (ADA) and manufactured by Hindustan Aeronautics Limited (HAL) for t ...

250 kg and 450 kg HSLD

Each HSLD bomb variant has two types of tail unit — retarder tail unit (RTU) (for low-level bombing missions) and ballistic tail unit (BTU) (for

strategic Strategy (from Greek στρατηγία ''stratēgia'', "troop leadership; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art o ...

high level bombing High level bombing (also called high-altitude bombing) is a tactic of dropping bombs from bomber aircraft in level flight at high altitude. The term is used in contrast to both World War II-era dive bombing and medium or low level bombing. Pri ...

). The 250 kg and 450 kg HSLD bomb uses Dentex as their primary explosive. On 29 July 2023, Ordnance Factory Muradnagar of Yantra India flagged off the first batch of 780 bomb casings of HSLD-450.

PGHSLD-500

The Precision Guidance Kit for 450 kg HSLD Bomb, designated PGHSLD-500, has a mass of and a length of 3.1 metre. The 450 kg HSLD has a

high-explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An exp ...

fragmented warhead with AVU-ETM fuse. The PGK consists of two sub-units — Nose Extension Unit (NEXU) and Smart Tail Unit (STU). The NEXU includes fixed canards as

flight control surfaces Flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude. The primary function of these is to control the aircraft's movement along the three axes of rotation. Flight control surfaces ...

(SAL) seeker, anti-jamming

GPS The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geol ...

antenna, two-axis gimballed laser with a range of 4 km and 20°

field of view The field of view (FOV) is the angle, angular extent of the observable world that is visual perception, seen at any given moment. In the case of optical instruments or sensors, it is a solid angle through which a detector is sensitive to elec ...

. The STU includes actuation system with four individually controlled fins, fibre-optic gyro-based

INS INS or Ins may refer to: Places * Ins, Switzerland, a municipality * Creech Air Force Base (IATA airport code INS) * Indonesia, ITF and UNDP code INS * INS Park, an entertainment complex in China Biology *'' Ins'', a New World genus of bee flie ...

module, GPS antenna, electrically initiated thermal battery, a flight control unit (FCU) and a telemetry module. When paired with the guidance kit, the bomb can achieve an accuracy of 30 m CEP with

mid-course guidance and that of 3 m CEP with SAL seeker as terminal guidance. The bomb is compatible with

Su-30MKI The Sukhoi Su-30MKI (NATO reporting name: Flanker-H) is a two-seater, twinjet multirole air superiority fighter developed by Russian aircraft manufacturer Sukhoi and built under licence by India's Hindustan Aeronautics Limited (HAL) for th ...

and

500 kg General Purpose (GP) Bomb

The 500 kg GP Bomb carries 10,300 preformed fragmented steel shells of 15 mm diameter. Each shell can target an area of up to 50 m from place of

detonation Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...

with fragment density of >1 hit/sq m. The bomb is compatible with Russian and

fighter aircraft. The bomb has both impact and impact delay modes of explosion and utilises

Torpex Torpex ("Torpedo explosive") is a secondary explosive, 50% more powerful than TNT by mass. Torpex comprises 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942, at which time some used the names Torp ...

-4B mixed with

RDX RDX (Research Department Explosive or Royal Demolition Explosive) or hexogen, among other names, is an organic compound with the formula (CH2N2O2)3. It is white, odorless, and tasteless, widely used as an explosive. Chemically, it is classified ...

that act as

explosive booster An explosive booster is a sensitive explosive charge that acts as a bridge between a (relatively weak) conventional detonator and a low-sensitivity (but typically high-energy) explosive such as TNT. By itself, the initiating detonator would not d ...

. The

Ministry of Defence A ministry of defence or defense (see American and British English spelling differences#-ce.2C -se, spelling differences), also known as a department of defence or defense, is the part of a government responsible for matters of defence and Mi ...

(MoD) gave the green light to start mass production of 500 kg GP Bomb by

Munitions India Limited Munitions India Limited (MIL) is an Indian state-owned defence company, headquartered in Pune, India, established in 2021 as part of the restructuring and corporatisation of the Ordnance Factory Board into seven different Public Sector Undertaki ...

at Ordnance Factory Khamaria (OFK). On 10 January 2022, under the guidance of a team from

HEMRL High Energy Materials Research Laboratory (HEMRL) is one of the premier laboratories of the Defence Research and Development Organisation (DRDO) located in Pune Maharashtra. Main area of works of the lab include research and development of high ...

and

ARDE Ardeh (also known in pre-Christian times as Ardata) is a village in Zgharta District, in the Northern Governorate of Lebanon. It is an ancient and historic town that was known during the 14th century B.C. as "Ardata". The "Tallet" (hill) of Ard ...

, the first two 500-kg GP bomb were carefully filled with primary and secondary warhead fillings in the F-6 section of the factory. The first batch of 48 such bombs was delivered to the Indian Air Force on 3 April 2022.

Further development

HSLD Mk 2

The HSLD Mk 2 is reportedly an improved variant of the earlier versions with a range of when launched from an altitude of . On 7 August 2024, IAF issued a Request for Proposal (RFP) was floated by the

for the upgrade of 24 MiG-29s, to integrate HSLD Mk 2 bombs with a range of 180 km. These upgrade will include addition of additional hardware (

bomb racks The bomb bay or weapons bay on some military aircraft is a compartment to carry bombs, usually in the aircraft's fuselage, with "bomb bay doors" which open at the bottom. The bomb bay doors are opened and the bombs are dropped when over the ...

on external

hardpoints A hardpoint is an attachment location on a structural frame designed to transfer force and carry an external or internal load. The term is usually used to refer to the mounting points (more formally known as a weapon station or station) on th ...

) as well as necessary software on to the aircraft. The project shall be overseen by No. 11 Base Repair Depot (BRD) of the IAF. Subsequently, the entire fleet will be equipped with this in phases. HSLD Mk 2 is integrated and deployed on Su-30MKI and SEPECAT Jaguar fleet. The IAF has sought MoD for manufacturing HSLD Mk 2 in India. In May 2025, it was reported that IAF plans to modify 112 Jaguar aircraft in order to equip them with HSLD Mk 2 bombs. This will follow the modifications of one fighter and trainer each of the DARIN II and III upgrades by

Hindustan Aeronautics Limited Hindustan Aeronautics Limited (HAL) is an Indian public sector aerospace and defence company, headquartered in Bengaluru. Established on 23 December 1940, HAL is one of the oldest and largest aerospace and defence manufacturers in the world. H ...

and IAF's Aircraft and Systems Testing Establishment (ASTE).

Tactical Advanced Range Augmentation (TARA)

Defence_Minister_Rajnath_Singh_explained_about_TARA_Glide_bomb_kit

The Tactical Advanced Range Augmentation (TARA) Range Extension Kit (REK) is guidance kit that converts the HSLD and GP series unguided bombs into

. The TARA is under development with DRDO as of 2024. The REK kit uses a wing and tail unit to glide for a longer distance before hitting its target. The TARA REK will incorporate

and

guidance for enhanced precision. The expected range of the bomb is 150-180 km when launched at 5 km altitude and a speed of

0.8. The CEP of the kit should be <5 m This plan is included in Innovation for Defence excellence Programme (iDEX) of the

. There will be 3 variants of REK kit — 250 kg (HSLD-250), 450 kg (HSLD-450) and 500 kg (500 kg GP Bomb). In March 2024, the first REK-equipped HSLD 250 was showcased in March 2024. The

can be equipped with the guided bombs.

Trials

Two successful developmental trials were conducted in 2013 to prove the capability of the munition with all development related works to be completed by 2014. During the same time, the Precision Guidance Kit for 450 Kg HSLD Bomb, designated PGHSLD-500, underwent carriage as well as carriage and release trials (CRTs) in the

Pokhran Test Range Pokhran (official spelling Pokaran; ) is a town and a municipality located 112 km east of Jaisalmer city in the Jaisalmer district of the Indian state of Rajasthan. It is situated in the Thar Desert region. Surrounded by rocks, sand and ...

. Two weapons were employed — one equipped with sensors, telemetry, and a data logger for carriage trials, and the other fitted with GPS and telemetry for Captive Release Trials (CRT). Two captive sorties with the weapon were conducted for carriage trials. The PGHSLD-500, mounted on station 05/06, was cleared for the full flight envelope. The weapon was released from an altitude of and at an

airspeed In aviation, airspeed is the speed of an aircraft relative to the air it is flying through (which itself is usually moving relative to the ground due to wind). In contrast, the ground speed is the speed of an aircraft with respect to the sur ...

of . The trials were completed successfully. The trials were carried out by a

aircraft from No. 31 Squadron, 32 Wing, Jodhpur Air Force Station (AFS). In May–June 2017, the ARDE conducted successful trials of the 500 kg GP Bomb from Jodhpur AFS. The tests covered ground adaptation, carriage and handling, limited separation, and release from a Su-30MKI aircraft. Carriage trials reached the upper limit of

0.85 Mach at 150 m altitude, with 6.5 g and full-roll manoeuvres. The bomb maintained structural integrity and was safely released from station 7. Upon impact, the live bomb functioned effectively, validating the complete explosive train and proving operational readiness. The trials were conducted with the help of Aircraft and Systems Testing Establishment (ASTE),

(HAL) and Office of the Regional Director Aeronautical Quality Assurance (ORDAQA) among others. As of April 2025, TARA is undergoing trials with SEPECAT Jaguar aircraft of the Indian Air Force.

Variants

* High Speed Low Drag Bomb – 250 kg and 450 kg * General Purpose Bomb – 500 kg * Precision Guided Bomb (PGHSLD) – 500 kg (HSLD-450) * Tactical Advanced Range Augmentation (TARA) – 250 kg, 450 kg and 500 kg

Operators

; *

References

Footnotes

# DRDO tested ATGM NAG successfully. DRDO Newsletter. August 2017 Issue.

External links

* {{Defence Research and Development Organisation (DRDO) Defence Research and Development Organisation Aerial bombs of India Targeting (warfare) Guided bombs