GBU-31

GBU-31. The GBU-31 is a precision-guided aerial bomb belonging to the Joint Direct Attack Munition (JDAM) family, developed for the United States Armed Forces. It converts existing unguided Mk 84 general-purpose bombs or BLU-109 penetrator warheads into all-weather, GPS-guided munitions. Entering service in 1999, it has become a cornerstone of American and allied air power, seeing extensive use in conflicts from the War in Afghanistan to the 2023 Israel–Hamas war.

Overview

The GBU-31 is a key component of the Joint Direct Attack Munition program, a joint development effort between the United States Air Force and the United States Navy. Its primary purpose is to provide a highly accurate, cost-effective, and weather-independent bombing capability. The system consists of a guidance tail kit attached to a standard Mk 84 or BLU-109 bomb body, using integrated inertial navigation and Global Positioning System data for targeting. This allows aircraft like the F-15E Strike Eagle, B-52 Stratofortress, and F-35 Lightning II to engage fixed targets with high precision from significant standoff ranges and in adverse conditions.

Design and development

The development of the JDAM kit, which produces the GBU-31, was initiated in the 1990s to address limitations of purely laser-guided weapons like the GBU-10 Paveway II during poor weather. Boeing was selected as the prime contractor. The design integrates a new tail section containing a GPS receiver, an Inertial measurement unit, and aerodynamic control fins onto existing Department of Defense bomb inventories. Critical testing was conducted at sites like Eglin Air Force Base and the Naval Air Weapons Station China Lake. The program achieved Initial operating capability in 1999, with the GBU-32 (using a Mk 83 warhead) and the GBU-35 (using a BLU-110 warhead) developed concurrently under the same JDAM architecture.

Operational history

The GBU-31 entered combat during the NATO bombing of Yugoslavia in 1999. It saw massive use in the War in Afghanistan following the September 11 attacks and during the Iraq War, launched from platforms including the B-1 Lancer, B-2 Spirit, and F/A-18 Hornet. The munition has been continuously employed in operations against the Islamic State of Iraq and the Levant in Syria and Iraq. It has been exported to numerous allies, including the Royal Australian Air Force, the Israeli Air Force, and the Ukrainian Air Force. The Ukrainian Air Force has employed them on modified Sukhoi Su-24 aircraft against Russian Armed Forces targets. The Israeli Air Force has used them extensively during the 2023 Israel–Hamas war in the Gaza Strip.

Variants

The primary variants are defined by their warhead. The **GBU-31(V)1/B** uses the 2,000-pound Mk 84 general-purpose bomb with Tritonal explosive. The **GBU-31(V)2/B** uses the 2,000-pound BLU-109 hardened penetrator warhead, filled with AFX-757, designed for fortified targets like bunkers and hangars. A specialized variant, the **GBU-31(V)3/B**, incorporates the BLU-117 warhead. Further development led to the **GBU-31(V)4/B**, which features a more sensitive FMU-152 fuze for optimized detonation. The guidance kits themselves have evolved through multiple Pre-Planned Product Improvement cycles, enhancing GPS anti-jam capabilities and integration with systems like the F-22 Raptor.

Specifications

* **Weight:** 2,000 lb (907 kg) * **Length:** 154 in (3.91 m) * **Diameter:** 14.5 in (368 mm) * **Warhead:** Mk 84 or BLU-109 / BLU-117 * **Explosive:** 945 lb (429 kg) Tritonal or AFX-757 * **Guidance:** INS/GPS * **Accuracy:** Circular error probable of less than 5 meters * **Tail Kit Contractor:** Boeing * **Unit Cost:** Approximately $25,000 per JDAM guidance kit (FY2021) * **Compatible Aircraft:** B-52 Stratofortress, B-1 Lancer, B-2 Spirit, F-15E Strike Eagle, F-16 Fighting Falcon, F/A-18 Hornet, F-22 Raptor, F-35 Lightning II, AV-8B Harrier II, Panavia Tornado, and others.

Category:Aerial bombs of the United States Category:Precision-guided munitions Category:Boeing weapons