Analysis | Which bunker-buster bomb did Israel use to eliminate Hezbollah leader Nasrallah in Beirut?.

On September 27, 2024, the Israeli Air Force's (IAF) 69th Squadron conducted an airstrike on an underground bunker in southern Beirut, resulting in the death of Hezbollah leader Hassan Nasrallah and multiple senior officials. The operation employed F-15I Ra'am fighter jets that took off from Hatzerim Airbase, each carrying six GBU-31(V)3/B bunker-buster bombs. Approximately 80 tons of explosives were used, including 85 of these bombs designed to penetrate reinforced structures. The targeted bunker, located about 18 meters underground, was heavily fortified, and the operation followed months of planning based on intelligence confirming Nasrallah's location.
Follow Army Recognition on Google News at this link

The Israeli Air Force's (IAF) 69th Squadron employed F-15I Ra'am fighter jets that took off from Hatzerim Airbase, each carrying six GBU-31(V)3/B bunker-buster bombs, to carry the strike against Nasrallah's bunker. (Picture source: Israeli MoD)

The GBU-31(V)3/B is a variant of the Joint Direct Attack Munition (JDAM), designed for precision strikes against hardened and deeply buried targets. It features the BLU-109 penetrator warhead, which is crucial for engaging reinforced structures effectively.

The BLU-109 warhead weighs about 874 kg, with approximately 240 kg of high-explosive fill. Its weight distribution is optimized to enhance penetration capability. Made from high-strength steel, the casing allows the warhead to maintain integrity upon impact, capable of penetrating 1.8 to 2.4 meters of reinforced concrete, depending on impact velocity and angle. The explosive fill is Tritonal, a mix of 80% TNT and 20% aluminum powder, chosen for its high-energy output and effectiveness in target destruction.

The GBU-31(V)3/B's guidance system relies on the KMU-557B/B Guidance Set, which includes guidance electronics, three movable control fins, one fixed control fin, a GPS antenna for satellite signals, and a 1760 connector that interfaces with the aircraft's systems, ensuring precise trajectory adjustments during flight.

The GBU-31(V)3/B is a variant of the Joint Direct Attack Munition (JDAM) that can be released from altitudes up to 15,240 meters at speeds ranging from Mach 0.6 to Mach 1.2. (Picture source: US DoD)

For stability and aerodynamic control, the GBU-31(V)3/B utilizes strakes made of a cast aluminum hardback and two formed steel panels, with attachment straps ensuring secure integration with the guidance kit, supporting guidance and stability.

The GBU-31(V)3/B is compatible with FMU-143 and FMU-152 series fuzes, activated by FZU-32 or FZU-55/63 initiators. The FMU-143 provides delayed-action capability for deeper penetration before detonation, while the FMU-152 offers programmable delay settings, adapting to various target types.

The guidance system incorporates both an Inertial Navigation System (INS) and a GPS-aided guidance system. The INS provides trajectory control if the GPS signal is lost, while the GPS-aided system enhances accuracy by processing up to 12 satellite signals, achieving a Circular Error Probable (CEP) of about 5 meters.

The tail assembly includes the Tail Actuator Subsystem (TAS), rotated 180 degrees compared to other JDAM variants, resulting in a unique fixed fin position. (Picture source: US DoD)

The tail assembly includes the Tail Actuator Subsystem (TAS), a lithium thermal battery, the GPS antenna, the Guidance Control Unit (GCU), and fin control mechanisms. The TAS is rotated 180 degrees compared to other JDAM variants, resulting in a unique fixed fin position.

The GBU-31(V)3/B can be released from altitudes up to 15,240 meters at speeds ranging from Mach 0.6 to Mach 1.2. It undergoes several flight phases: separation with fins locked, optimal guidance using GPS and INS data, and impact, where it adjusts its angle for optimal penetration before detonation.

The BLU-109 warhead, combined with the KMU-557B/B JDAM guidance kit, makes the GBU-31(V)3/B highly effective against fortified targets. It can penetrate 1.8–2.4 meters of reinforced concrete before detonation, with its effectiveness influenced by delivery speed and angle.

The BLU-109 penetrator warhead, combined with the KMU-557B/B JDAM guidance kit, can penetrate 1.8–2.4 meters of reinforced concrete before detonation, with its effectiveness influenced by delivery speed and angle. (Picture source: US DoD)

The F-15I "Ra'am" (Thunder) is an Israeli variant of the American McDonnell Douglas (now Boeing) F-15E Strike Eagle, developed to meet the Israeli Air Force's (IAF) requirements for a long-range precision strike aircraft capable of operating in complex and heavily defended airspaces. Israel acquired the F-15I as part of its broader effort to modernize and maintain air superiority in the Middle East, following the challenges experienced during the 1991 Gulf War. The decision to acquire the F-15I was made in 1994, with the first aircraft delivered in 1997, and the variant was officially introduced into service in 1998.

The F-15I features Israeli-specific avionics and systems that differentiate it from the base F-15E model. Notable additions include the Elisra SPS-2110 integrated electronic warfare suite, the Dash IV helmet-mounted display system, and other locally produced systems designed to enhance situational awareness and target acquisition. Retaining the two-seat configuration with a pilot and weapons systems officer, the aircraft is capable of performing both air-to-air and air-to-ground missions, providing a range of operational options for the IAF.

Regarding technical specifications, the F-15I has a maximum speed of Mach 2.5 (approximately 3,000 km/h) and a combat range of around 1,400 km when equipped with external fuel tanks. It is powered by two Pratt & Whitney F100-PW-229 engines, each generating 29,000 pounds of thrust, allowing for high acceleration and maneuverability. The aircraft has a service ceiling of 20,000 meters and a maximum takeoff weight of 36,700 kg, with an external payload capacity of up to 8,165 kg (18,000 pounds). It is equipped with the APG-70 radar system, supporting long-range target detection and engagement capabilities.

The Israeli decision to acquire the F-15I Ra'am was made in 1994, with the first aircraft delivered in 1997, and the variant was officially introduced into service in 1998. (Picture source: Israeli MoD)

Recently, the U.S. government approved an upgrade and expansion of the Israeli F-15I fleet, which includes the acquisition of up to 50 new F-15IA (Israel Advanced) aircraft and Mid-Life Update (MLU) kits for the existing 25 F-15I aircraft. This upgrade package, valued at approximately $18.82 billion, is intended to enhance the IAF’s ability to address evolving security challenges. The upgrade aims to align the F-15I with the advanced capabilities of the F-15IA and is expected to ensure the aircraft remains relevant in the face of modern threats.

The F-15I upgrade package includes 120 F110-GE-129 engines, 90 Advanced Display Core Processors II, and 75 APG-82(V)1 Active Electronically Scanned Array (AESA) radars, which are expected to improve target detection and engagement. Additional upgrades include 50 AN/AAQ-13 LANTIRN navigation pods, 320 LAU-128 Advanced Medium Range Air-to-Air Missile (AMRAAM) launchers, and 180 Embedded Global Positioning System/Inertial Navigation System (EGI) devices with M-Code. These upgrades are intended to enhance the aircraft's overall operational capability.

In terms of armament, the F-15I can carry a wide array of weaponry, including air-to-air missiles such as the Python series and AIM-120 AMRAAM, as well as air-to-ground munitions like Paveway laser-guided bombs, Joint Direct Attack Munitions (JDAMs), BLU-109 "bunker-buster" bombs, SPICE bombs, and AGM-88 High-speed Anti-Radiation Missiles (HARM). The combination of advanced avionics, radar systems, and versatile weapons load enables the F-15I to fulfill various mission requirements within the IAF's operational framework.

Powered by two Pratt & Whitney F100-PW-229 engines, the F-15I has a maximum speed of Mach 2.5 (approximately 3,000 km/h) and a combat range of around 1,400 km when equipped with external fuel tanks. (Picture source: Israeli MoD)