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Eventually Air Force experts plan to equip the B-2 long-range strategic bomber to carry as many as 216 Small Diameter Bombs on each mission.
GBU-39 variant of the Small Diameter Bomb has guidance from the satellite Global Positioning System (GPS), as well as from an inertial gyro. The future GBU-40 variant will have a terminal seeker with automatic target recognition capabilities for mobile and relocatable targets.
The bomb measures 5.9 feet long and weighs 285 pounds, and is to increases the number of weapons an aircraft can carry, as well as reduce collateral damage. The bomb has a range of more than 60 miles, and can operate in bad weather.
The F-22, for example, will carry up to eight GBU-39s in its two internal weapons bays for attack missions. The B-2 could potentially deliver up to 216 SDBs in one load.
Interesting Read On the SDB Program
Originally posted by kilcoo316
The B-2 is a strategic platform, the SDB essentially a tactical weapon.
B-2s are not going to be doing CAS missions - they'll be going after bridges, power stations, command facilities etc.
Originally posted by kilcoo316
Does an SDB have the punch to take out such things? Or are bigger bombs with a bit more bite the norm?
Although the SDB is significantly smaller than existing bombs, its warhead is still adequate for many typical targets. E.g. its steel and concrete penetration capability is similar to that of the much larger 2000 lb BLU-109/B warhead. Therefore the SDB enables USAF bombers to attack more targets per sortie. The smaller warhead will also tend to reduce collateral damage.
The US Air Force is developing a Focused Lethality Munition warhead for the Small Diameter Bomb. The new warhead employs multi-phase blast explosive and a composite carbon fiber warhead case, allowing for pinpoint strikes with low collateral damage. The FLM warhead technology was developed at the Lawrence Livermore National Laboratory and the U.S Air Force Research Laboratory.
The small-diameter bomb is a 250-pound class munition, providing the warfighter with a four-fold increase in weapons per aircraft station. It can penetrate more than 13 feet into a target and can be accurate from up to 70 miles away.
The Small Smart Bomb is a 250 pound weapon that has the same penetration capabilities as a 2000lb BLU-109, but with only 50 pounds of explosive. The 250 pound-class warhead that has demonstrated penetration of more than 6 feet of reinforced concrete. With the INS/GPS guidance in conjunction with differential GPS (using all 12 channel receivers, instead of only 5) corrections provided by GPS SPO Accuracy Improvement Initiative (AII) and improved Target Location Error (TLE), it can achieve a 5-8m CEP. The munition, with a smart fuze, has been extensively tested against multi-layered targets by Wright Laboratory under the Hard Target Ordnance Program and Miniature Munitions Technology Program. The length to diameter ratio and nose shape are designed to optimize penetration for a 50lb charge.
In early ground testing, the weapon's ability to penetrate six feet of reinforced concrete was demonstrated. In subsequent testing, a total of five weapons were dropped against targets with surveyed aim points (no target location error). The bombs' accuracy was achieved through the use of a Differential Global Positioning System (GPS) guidance unit. A few tests demonstrated the abilityof the Munitions Directorate-developed Hard Target Smart Fuze to initiate bomb detonation at the optimum location duringpenetration.
The miniaturized munition concept was a weapon that is six feet long, six inches in diameter, and weighs only 250 pounds with approximately fifty pounds of Tritonal explosive material. The weapon is effective against a majority of hardened targets previously vulnerable only to munitions in the 2,000 pound class.
Modifications currently under way will allow each B-2 to carry 80 500-pound GBU-38 JDAMs. The B-2 can also carry eight of the massive 5,000-pound GBU-37 bunker-buster bombs, and may eventually carry a pair of the 30,000-pound Massive Ordnance Penetrators. Proponents claim that by 2007 the B-2 could carry 216 [some accounts say as many as 324] of the 250-pound SDBs. Each BRU-61/A smart pneumatic carriage holds four SDB weapons, the rack weighs 320 pounds (145 kg) empty, and 1,460 pounds (664 kg) loaded with four 285 pound (130 kg) bombs. In principle, the B-2 has a total of 80 attachment points for the 500-lb MK82 GBU-30 JDAM, each of which could accommodate a single BRU-61/A rack, for a total of 320 SDB weapons. In practice, the resulting 117,000 lbs (53,000 kg) weight would exceed the B-2's nominal 40,000 pound (18,000 kilogram) payload by some wide margin. The bomber could of course trade up for somewhat more payload by trading off against fuel and un-refueled range. The widely cited 216 SDB carriage would result in 54 BRU-61/A racks, 27 in each bomb bay, for a total 78,800 pound (35,800 kilogram) payload, roughly double the nominal value.
Modifications currently under way will allow each B-2 to carry 80 500-pound GBU-38 JDAMs. The B-2 can also carry eight of the massive 5,000-pound GBU-37 bunker-buster bombs, and may eventually carry a pair of the 30,000-pound Massive Ordnance Penetrators.
80X500lbs = 40,000lbs + 10,000lbs (SBRA) X2 = 60,000lbs.
8X5,000lbs = 40,000lbs + 5,000lbs X2 (MPRL) = 50,000lbs.
2X 30,000lbs = 60,000lbs (parent loaded like the B-53 to the upper roofmounts)
216 X 285 = 61,560lbs + 10,000lbs X2 (SBRA _without BRU-61 addition) = 80,000lbs.
i.e. You are pushing the absolute weight of the other loadout options JUST with the munition totals of the SDB alone. Even before you include the SBRA/BRU-61 weights.
Proponents claim that by 2007 the B-2 could carry 216 [some accounts say as many as 324] of the 250-pound SDBs. Each BRU-61/A smart pneumatic carriage holds four SDB weapons, the rack weighs 320 pounds (145 kg) empty, and 1,460 pounds (664 kg) loaded with four 285 pound (130 kg) bombs.
And 8X 1,460lbs = 11,680lbs. Which is more than reasonable for a jet looking to go from 16 to 64 shots WHILE GAINING a 50nm standoff option unavailable with the GBU-38. Nobody wants to see a B-2 come like a falling leaf down ala F-117 because the ballistic munition requires target overflight into the heart of the defensive envelope + sensor crosscoverage!
In principle, the B-2 has a total of 80 attachment points for the 500-lb MK82 GBU-30 JDAM, each of which could accommodate a single BRU-61/A rack, for a total of 320 SDB weapons.
NO IT DOES NOT! The B-2 has _two_ primary bay attachments into which you 'clipload' either an MPRL or an SBRA.
The SBRA has _40_ attachment points for Mk.82 class munitions of which the GBU-38 is carriage factor typified by it's 92.64" length, 17" finspan and 558lb weight.
The BRU-61 is _143"_ long and (empty) weighs 320lbs. Loaded it weighs 1,460lbs and is probably another 16" longer yet as the GBU-39 protrudes beyond BOTH ENDS by a good 6-8 inches.
As such, I doubt if you can even manage what they do on the B-1B when carrying Mk.82 AIR munitions which is to stagger the bomb rows at the cost of a couple weapons per rack.
Indeed, the closest I can compare to is when they 'reconfigured' a few CBMs to carry SUU-60 class TMDs and ended up permanently restressing the rack and derating it from 26-28 to 10 munitions on a weight change of only about 400 pounds per bomb.
In practice, the resulting 117,000 lbs (53,000 kg) weight would exceed the B-2's nominal 40,000 pound (18,000 kilogram) payload by some wide margin.
No freakin' kidding.
The bomber could of course trade up for somewhat more payload by trading off against fuel and un-refueled range. The widely cited 216 SDB carriage would result in 54 BRU-61/A racks, 27 in each bomb bay, for a total 78,800 pound (35,800 kilogram) payload, roughly double the nominal value.
I doubt it, seriously.
Wiring up the B-1's CBM for WCMD and JDAM carriage was originally supposed to be a plug'n'play 'ECBM' enhancment. Now I understand it to be a completely new rack with a different wiring group and computer interface as the 'ACBM'. The old modules are still capable of dumb + cluster release. But only those with the current 1760 wiring TO THE INDIVIDUAL RACKS are able to handle the precision weapons of Block-E.
It being worth noting that the B-1 is also going to carry GBU-39 on the CRLs _not_ in the CBMs and given that there are roughly 3 times as many B-1Bs as B-2As with an order of magnitude greater signature vulnerability, the automatic question must be "Why not double their standoff bombload configuration through CBM carriage too?"