How to make a dumb bomb smarter
April 16, 2008 Boeing has begun delivering the first Laser Joint Direct Attack Munition (LJDAM) kits to the U.S. Air Force. The Precision Laser Guidance Set (PLGS) kits are being produced to satisfy the Air Force and Navy's urgent need for engagement of fast-moving land targets. The LJDAM expands the capabilities of the Joint Direct Attack Munition (JDAM), which is a low-cost guidance kit that converts existing unguided free-fall bombs into near-precision guided “smart” weapons.
One of the take-outs of Operation Desert Storm was that the US armed forces had a shortfall in air-to-surface weapon capability. The adverse weather conditions encountered there limited the employment of precision guided munitions and the accuracy of unguided dumb bombs was also degraded when they were delivered from medium and high altitudes.
Research and development of an "adverse weather precision guided munition" began in 1992. The first JDAMs were delivered in 1997 with initial operational testing conducted in 1998 and 1999. More than 450 JDAMs were dropped during this testing, recording an unprecedented 95 percent system reliability while achieving a 9.6-meter accuracy rate. JDAM performance has been demonstrated in operationally representative tests including drops through clouds, rain and snow. These tests included a B-2 releasing 80 JDAMs on a single pass against multiple targets – a site to behold, no doubt!
The US$22,000 JDAM kit consists of a tail section that contains a Global Positioning System/Inertial Navigation System suitable for guiding the bomb onto a target in any flyable weather, plus body strakes to give the bomb additional stability and lift. The US$46,000 Laser JDAM kits add a modular laser sensor that can be installed in the field into the nose of existing JDAM weapons and adds mission flexibility to the package so that targets of opportunity, including mobile targets travelling at up to 70 mph, can be accurately engaged. People likely to have a JDAM calling should beware. Initially the LJDAM kit is being made for the GBU-38 bomb which carries a 500 pound warhead but follow-on integration with the brutal 1,000-pound GBU-32 and it’s awesome sibling the GBU-31, which carries a 2,000-pound warhead.
The initial $28 million LJDAM contract, awarded in May 2007, will add 600 laser seekers to the services' existing inventory of 500-pound bombs, which means the kits come at US$46,667 a pop.
The First Article Acceptance Testing (FAAT) of production units was completed in March with the Air Force performing the FAAT guided flight tests at the China Lake test range with drops from F-15E and F-16 aircraft. The tests demonstrated LJDAM's ability to engage and destroy targets moving at up to 70 miles per hour. The Navy also initiated its LJDAM guided flight test program in March with multiple drops from an AV-8B against moving targets. Additional Navy testing is planned from an F/A-18. LJDAM is expected to be operational this year with both the Air Force and Navy. Boeing will deliver the contracted kits by June 2009.
"Boeing's early investment in Laser JDAM technology laid the foundation for meeting this urgent operational need to intercept high-speed targets. Because of Boeing's strong belief in Laser JDAM, we were able to deliver a capability to the warfighter in 11 months," said Lynda Rutledge, director of 708th Armament Systems Group at Eglin Air Force Base, Fla.
"This on-schedule transition to production and overall fielding effort has been a great team effort between Boeing, our customer and our suppliers," said Dan Jaspering, Boeing Direct Attack program manager. "We are truly excited to be getting this urgently needed capability to the warfighters."
The Laser JDAM PLGS is a modular laser sensor kit uses a laser sensor supplier by EFW, based in Fort Worth, Texas.