Description
The Joint Direct Attack Munition (JDAM) is a guidance kit that converts existing unguided bombs into precision-guided "smart" munitions. The tail section contains an inertial navigational system (INS) and a global positioning system (GPS). JDAM improves the accuracy of unguided bombs in any weather condition and is fully integrated on Navy fighter-attack aircraft such as the AV-8B, F/A-18 and F-35. JDAM with the addition of a Precision Laser Guidance Set (PLGS) becomes Laser JDAM (LJDAM), a flexible dual mode weapon utilizing Laser and GPS aided INS to guide the weapon.

Features
JDAM and LJDAM are guided air-to-surface weapons using either the 2000 lb BLU-109 hard-target-penetrator, the 2000-pound MK 84/BLU-117, the 1,000-pound MK 83/BLU-110, or the 500-pound MK 82/BLU-111/BLU-126 warheads as the payload and can be configured with a variety of fuzing systems or proximity sensors. JDAM enables aircraft to employ weapons accurately against stationary ground targets, while LJDAM enables prosecution of moving and maneuvering ground targets.  The Global Positioning System (GPS)-aided Inertial Navigation System (INS) and PLGS are combined with a tail control system for guidance. Target coordinates can be loaded into the aircraft before takeoff, manually before weapon release, and automatically entered through target designation with onboard aircraft sensors. This information is transferred from the aircraft to the weapon prior to release.

Once released from the aircraft, the JDAM navigates to the target autonomously. In its most accurate mode, when GPS data is available or when using laser, the JDAM system will have an error of less than 6 meters (about 20 feet).

JDAM enables multiple weapon releases against single or multiple targets on a single pass. LJDAM enhances JDAMs providing aircrew with an airburst capability as well as targeting flexibility when prosecuting mobile relocatable targets or targets of opportunity.

Background
JDAM performance was demonstrated operationally during Operation Allied Force in 1999 during which 650 JDAMs were dropped and in Operations Southern Watch and Enduring Freedom; and in Operation Iraqi Freedom, with expenditures of more than 6,000 JDAMs against enemy targets. Additionally, tests included a spectacular display of B-2/JDAM conventional firepower in the release of 80 JDAMs from a B-2 on a single pass against multiple targets. JDAM provides the Navy with an all-weather, affordable, air-to-surface weapons with delivery accuracy exceeding requirements. The Navy received its first JDAM kits in May 1999.

LRIP for the 2,000-pound kits began in fiscal year 1997, and Milestone III was reached in fiscal year 2001. The 1,000-pound JDAM kit reached initial operational capability (IOC) in fiscal year 2002, and IOC for the 500-pound weapon occurred during the second quarter of fiscal year 2005.

In September 2006, the Departments of the Navy and Air Force put in place a low-cost, non-developmental enhancement to the GBU-38 (500-pound) JDAM to address moving targets. Open competition and source selection completed in February 2010, and the Navy awarded a contract to Boeing for a Direct Attack Moving Target Capability (DAMTC) and the material solution was Laser JDAM.  

LJDAM (GBU-54) is a 500-pound dual-mode weapon that couples the GPS/INS precision of the JDAM and laser-designated accuracy of a laser-guided bomb into a single weapon. LJDAM also provides added capability and flexibility to the Fleet's existing inventory of precision-guided munitions to satisfy the ground moving-target capability. LJDAM reached IOC in fiscal year 2012. The Navy has also developed the GBU-56 Laser JDAM for the BLU-109 penetrator to replace the legacy GBU-24 Paveway III weapons systems and improve performance in highly contested environments.

General Characteristics
Primary Function: Guided air-to-surface weapon
Contractor: Boeing Corporation
Unit Cost: Approximately $24,164
Length: (JDAM and warhead) GBU-31 (v) 2/B: 152.7 inches (387.9 centimeters); GBU-31 (v) 4/B: 148.6 inches (377.4 centimeters); GBU-32 (v) 2/B: 119.5 inches (303.5 centimeters); GBU-38/B: 92.64 inches
Wingspan: GBU-31: 25 inches (63.5 centimeters); GBU-32: 19.6 ins. (49.8 centimeters).
Weight: (JDAM and warhead) GBU-31 (v) 2/B: 2,036 pounds (925.4 kilograms); GBU-31 (v) 4/B: 2,115 pounds (961.4 kilograms); GBU-32 (v) 2/B: 1,013 pounds (460.5 kilograms); GBU-38/B: 590 pounds
Ceiling: 45,000-plus feet (13,677 meters)
Range: Up to 15 miles (24 kilometers)
JDAM Guidance System: Global Positioning System (GPS)-aided Inertial Navigation System (INS)