OVERVIEW: The GBU-54(V)3/B Laser Joint Direct Attack Munition (LJDAM) is an inertial and laser-guided, GPS-aided, glide bomb using a bolt-on guidance and aerodynamic package mated to a BLU-126/B Low Collateral Damage Bomb (LCDB).  It is intended to be used in strikes were low colleteral damage is a priority.  

DETAILS: LJDAM is intended to provide accurate delivery of general purpose bombs in adverse weather conditions.  The GBU-56(V)2/B differs from other JDAM versions by incorporating an laser terminal seeker. 

Before take off, mission plans including release envelope, target coordinates and weapon terminal parameters are loaded to the host aircraft prior to take off.  Before release,   INS alignment and targeting data and is automatically loaded to the weapon. 

Like the JDAM, LJDAM can be a "fire-and-forget" weapon system.  Once released, the bomb's INS/GPS guides the bomb to the target, allowing the launching aircraft to take evasive action without having to guide the weapon.  The INS is capable of guiding the JDAM to target independently of the GPS, albeit at a reduced accuracy.  However, for the enhanced accuracy provided by the laser seeker, the target must be illuminated by either a laser on the launching aircraft or "buddy-lasing" from another platform. This enhanced targeting capability is reduced  in adverse weather conditions or if the lasing platform must maneuver.

The LJDAM can be launched from very low to very high altitude and can be launched in a dive, toss, loft or in straight and level flight with an on-axis.  Off-axis delivery is also possible, albeit with a decrease in bomb range. LJDAM also allows multiple target engagements on a single pass delivery.

The BLU-126/B warhead is a BLU-111 with a smaller explosive charge and intert balast to maintain the BLU-111 aerodynamic characteristics.

Specifications: 


Weight: 		254kg
Length: 		2.352m
Wingspan:		0.356m 
Range:			13.0 nm (altitude dependant)
Accuracy:		CEP:  2 meters with laser; 30 meters using only 				inertial


NOTES:  IOC ???. Officially, the GPS-enhanced CEP of the weapon is cited as 13m, but real figures are reportedly approximately 10 meters.  The visible difference between the USAF's GBU-38(V)3/B and the Navy's GBU-38(V)4/B is that the USN bombs are coated with a thermal protection layer, giving the bombs a wrinkled grey external finish, in contrast to the USAF's smooth olive drab bomb bodies.
 
 
SOURCES: IHS. "GBU-31, GBU-32 and GBU-38 Joint Direct Attack Munition (JDAM)." Jane's Air-Launched Weapons, Feburary 2015;  "Joint Direct Attack Munition (JDAM) GBU-31 - Smart Weapons." Federation Of American Scientists. Accessed December 29, 2019. https://fas.org/man/dod-101/sys/smart/jdam.htm ; "Boeing JDAM." Designation-Systems.Net. Last modified August 21, 2008. http://www.designation-systems.net/dusrm/app5/jdam.html; Boeing, "Laser JDAM," https://www.boeing.com/resources/boeingdotcom/defense/weapons-weapons/images/laser_jadam_product_card.pdf