History and General Description:
~ in late 1991, U.S. Air Force and U.S. Navy formulated common requirements for a new class of low-cost general-purpose precision guided bombs
~ program was eventually named JDAM (Joint Direct Attack Munition)
~ after USAF had successfully demonstrated a GPS-aided inertial (a.k.a. GPS/INS) guidance package in 1993,
~ goal for JDAM became development of a low-cost GPS/INS add-on guidance kit for existing 1000 lb and 2000 lb class "dumb" bombs
~ McDonnell Douglas was selected in October 1995 as prime contractor for further development of JDAM
~ JDAM flight testing began in 1996, and first LRIP (Low Rate Initial Production) contract was awarded in April 1997
~ In December 1998, JDAM officially reached IOC (Initial Operational Capability) on first platform, USAF's B-52H
~ Other aircraft soon followed, and today all U.S. bombers and strike aircraft can carry JDAM weapons
~ JDAM add-on kits include 2000 lb MK 84, BLU-109/B and BLU-117/B, 1000 lb MK 83 and BLU-110/B, and 500 lb MK 82 and BLU-111/B
Main part of a JDAM add-on kit:
~ guidance and control section, which is mounted at tail of bomb body
~ this section houses INS unit, GPS receiver, control electronics, and cruciform tailfins (three moving, one fixed) to steer bomb
~ additionally, strakes are fitted to bomb body to enhance its stability and gliding capability
~ strakes are mounted to bomb's center body, except for 500 lb class bombs (MK 82, BLU-111/B)
~ using full GPS-aided INS guidance, accuracy of JDAM is officially quoted as 13 m (43 ft), but real figures are reportedly slightly better, around 10 m (33 ft)
~ when GPS is unavailable (e.g. because of jamming), accuracy in INS-only mode drops to 30 m (100 ft) CEP,
~ but that's still good enough for many purposes, and therefore GPS-jamming is far from disabling JDAM bombs
~ from typical operating altitudes, stand-off range of a JDAM is around 8-24 km (5-15 miles)
~ at any time in mission, delivery aircraft's pilot is informed if he is within valid drop envelope for desired target coordinates
Advantages
~ JDAM's big advantage over modern Paveway III laser-guided bombs is that JDAM operation is inherently simpler
~ it is all-weather capable, because you don't need to laser-designate target, and it's a true fire-and-forget weapon
~ it is slightly less accurate than LGBs, and can't be used on moving targets
~ efforts to supply JDAM with a terminal seeker to work around these shortcomings included DAMASK (Direct Attack Munitions Affordable Seeker),
~ which demonstrated between 1997 and 1999 an IIR (Imaging Infrared) seeker and associated control algorithms to improve CEP to 3 m (10 ft)
~ so far no terminal seeker has been adopted as a standard option for JDAM,
~ possibly because availability of GPS/INS-enhanced Paveway II and Paveway III laser-guided bombs makes such a capability less urgent
GBU-32/B and BLU-110/B
~ designation GBU-32/B was allocated early in JDAM program to 1000 lb class JDAM bombs with guidance kits from McDonnell Douglas (now part of Boeing)
~ current production JDAMs with 1000 lb class warheads are designated in GBU-32(V)/B (and formerly also GBU-35(V)/B) series
~ at least two different types of warhead can be used with 1000 lb JDAM tailkits:
~ MK 83: Standard 1000 lb LDGP (Low-Drag General Purpose) bomb
~ BLU-110/B: Instead of MK 83, Navy can also use BLU-110/B warhead in their GBU-32(V)2/B series JDAMs
~ BLU-110/B is externally identical to MK 83, but uses PBXN-109 thermally insensitive explosive
~ BLU-110A/B and -110B/B variants, which are ones that are actually used by Navy, have external protective coating
U.S Navy
~ GBU-32 (V)2 SeriesPIN LOCK
~ GBU-32(V)2/B
~ SAASM
~ GBU-32B(V)2/B
~ SAASM-AJ
~ GBU-32C(V)2/B
~ Warhead – MK 83 / BLU-110
~ Fuze - FMU-139B/B or C/B
~ MK 122 Safety Switch or FMU-139B/B or C/B
~ FZU-48/B Initiator
~ FZU-61/B Lanyard or FMU-139B/B or C/B
~ FZU-48/B Initiator
~ MK 3 Arming Wire
~ Nose – DSU-33B/B Sensor or Ogive (Nose Plug) or MXU-735 (Nose Plug)