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Differences between the B-1B and its predecessor, the B-1A of the 1970s, are subtle, yet significant. Externally, only a simplified engine inlet, modified over-wing fairing and relocated pilot tubes are noticeable. Other less-evident changes include a window for the offensive and defensive systems officers' station and engine housing modifications that reduces radar exposure. The B-1B was structurally redesigned to increase its gross takeoff weight from 395,000 to 477,000 pounds (177,750 to 214,650 kilograms). Still, the empty weight of the B-1B is but 3 percent greater than that of the B-1A. This added takeoff weight capacity, in addition to a movable bulkhead between the forward and intermediate weapons bay, allows the B-1B to carry a wide variety of nuclear and conventional munitions. The most significant changes, however, are in the avionics, with low-radar cross-section, automatic terrain-following high-speed penetration, and precise weapons delivery.
Prior to 1994 B-1B fleet had never achieved its objective of having a 75-percent mission capable rate. In 1992 and 1993 the B-1B mission capable rate averaged about 57 percent. According to the Air Force, a primary reason for the low mission capable rate was the level of funding provided to support the B-1B logistics support system. Concerned about the low mission capable rate, a history of B-1B problems, and the Air Force's plans to spend $2.4 billion modifying the B-1B to become a conventional bomber, the Congress directed the Air Force to conduct an Operational Readiness Assessment (ORA) from June 1, 1994, through November 30, 1994. The purpose of the ORA was to determine whether one B-1B wing was capable of achieving and maintaining its planned 75-percent operational readiness rate for a period of 6 months, if provided the full complement of spare parts, maintenance equipment and manpower, and logistic support equipment. During the ORA the test unit achieved an 84.3-percent mission capable rate during the test period. The ORA demonstrated that, given a full complement of spare parts, equipment, and manpower, the Air Force could achieve and sustain a 75-percent mission capable rate for the B-1B. The Air Force projects that the entire B-1B fleet will reach a 75-percent mission capable rate by 2000 by virtue of numerous on-going and future reliability, maintainability, and management initiatives. However, as of mid-October 1999 the Air Force wide mission capable rate of the B-1 had fallen to 51.1 percent -- mainly because of maintenance problems and a shortage of parts. Over the previous 12 months, the Kansas Guard had maintained a mission capable rate of 71.1 percent for the 10 usable aircraft assigned to it. Overall, the B-1B had mission capable rates of 51 percent to 62 percent in FY'00 and FY'01, below the goal of 75-percent.
The basis for the projection of useful life of the B-1 is the Aircraft Structural Integrity Program (ASIP). The useful life of the structure is assumed to be the point at which it is more economical to replace the aircraft than to continue structural modifications and repairs necessary to perform the mission. The limiting factor for B-1’s service life is the wing lower surface. At 15,200 hours, based on continued low level usage, the wing’s lower skin will need replacement. Current usage rates, operational procedures, and mishap attrition will place the inventory below the requirement of 89 aircraft in 2018, while the service life attrition will impact around 2038.
The first B-1B, 83-0065, The Star of Abilene, was delivered to the Air Force at Dyess Air Force Base, Texas, in June 1985, with initial operational capability on Oct. 1, 1986. The 100th and final B-1B was delivered May 2, 1988.
The Air Force chose to fully fund the operation of only 60 B-1Bs in the mid-1990s, compared with plans to fund 82 beyond fiscal year 2000. In the short term, the Air Force classified 27 of 95 B-1Bs as "reconstitution aircraft." These aircraft were not funded for flying hours and lacked aircrews, but they are based with B-1B units, flown on a regular basis, maintained like other B-1Bs, and modified with the rest of the fleet. B-1B units used flying hours and aircrews that were based on 60 operational aircraft to rotate both the operational aircraft and the reconstitution aircraft through its peacetime flying schedule. These 27 aircraft were maintained in reconstitution reserve status until the completion of smart conventional munition upgrades. By that time [around the year 2000], there were 95 aircraft providing an operational force of 82 fully modified B-1s. The B-1 will complete its buy back of attrition reserve by the fourth quarter of FY03, and re-code six training aircraft to attain 70 combat-coded aircraft by the fourth quarter of FY04.
During the Cold War, heavy bombers were used primarily for nuclear deterrence and were operated solely by the active duty Air Force. According to the Air Force, the National Guard's part-time workforce was incompatible with the bombers' nuclear mission because of a requirement for continuously monitoring all personnel directly involved with nuclear weapons. With the end of the Cold War and increased emphasis on the bombers' conventional mission, the Air Force initiated efforts to integrate Guard and reserve units into the bomber force. As part of its total force policy, the Air Force assigned B-1B aircraft to the National Guard. Heavy bombers entered the Air Guard's inventory for the first time in 1994 with a total of 14 B-1Bs programmed by the end of fiscal year FY 1997 for two units, the 184th Bomb Wing (BW), Kansas, and the 116th BW, Georgia. The 184th completed its conversion in FY 1996 at McConnell Air Force Base (AFB), Kansas. After a long political struggle that involved resisting the planned conversion from F-15s and an associated move from Dobbins AFB near Atlanta to Robins AFB near Macon, the 116th began its conversion on 1 April 1996. The unit completed that process in December 1998. All the bombers in both units were configured for conventional, not nuclear, missions.
Prior to 1994, the B-1B fleet operated out of four bases: Dyess Air Force Base, Texas; Ellsworth Air Force Base, South Dakota; McConnell Air Force Base, Kansas; and Grand Forks Air Force Base, North Dakota. In 1994, the Air Force realigned the B-1B fleet by closing the Grand Forks Air Force Base and transferring the aircraft at McConnell Air Force Base to the Air National Guard. With the transfer, the B-1B support structure, including spare parts, was distributed to the two remaining main operating bases. The concentration of aircraft and repair facilities at Dyess and Ellsworth Air Force Bases resulted in improved support capabilities, which improved mission capable [MC] rates.
On 26 March 1996 it was announced
that the 77th Bomb Squadron would return to Ellsworth. On 1 April 97, the
squadron again activated at Ellsworth as the geographically separated 34th
Bomb Squadron completed its transfer to its home at the 366th Wing, Mountain
Home AFB, Idaho. By June 1998, the 77th had six of its B-1Bs out of the
reconstitution reserve. This number ballanced those lost by the 34th BS.
The Advanced Conventional Bomb
Modules [ACBM] were uniquely designed to meet the needs of the B-1B
aircraft during the transition between Block D and Block E. All the munitions
personnel have to do is switch a circuit card and one cable, and the modules
will be ready for Block E. With the upgrade, the B-1B's will be able to
employ Wind Corrected Munitions Dispensers and will still be able to carry
Mk-82, 500-pound bombs and cluster bomb units. The upgrade helps weapons
loading capabilities keep up with changes to the aircraft's on-board computer
systems. The aircraft are upgrading from 1970's vintage computers to the
capability of today's computers," he said. "This upgrade also includes
a new avionics flight software package. With this upgrade, operators needed
new bomb modules that were compatible with the new computers.
The 28th Munitions Squadron received shipment of the first two of 13 new Advanced Conventional Bomb Modules 03 April 2000, taking the B-1B one step closer to Block E integration. The new ACBMs differ from the ones currently used as the new modules already have the wiring and electronics capability required to handle Block E weapons upgrades. A bomb module seats inside an aircraft bomb bay and is configured to hold different types and sizes of bombs. Ellsworth is the first bomber base to receive the new modules. The new ACBMs were available for use by base bomb squadrons in mid-May 2000, and the remaining modules were delivered by mid-September 2000.
Cockpit Upgrade Program (CUP) - Current B-1 cockpit display units are not capable of supporting graphic intensive software modifications. The CUP installs a robust graphic capability via common display units throughout the front and aft stations. This program increases B-1 survivability by providing critical situational awareness displays, needed for conventional operations, keeping pace with current and future guided munitions integration, enhancing situational awareness, and improving tactical employment.
Link-16 – Providing Line-of-Sight (LOS) data for aircraft-to-aircraft, aircraft-to-C2, and aircraft-to-sensor connectivity, Link-16 is a combat force multiplier that provides U.S. and other allied military services with fully interoperable capabilities and greatly enhances tactical Command, Control, Communication, and Intelligence mission effectiveness. Link-16 provides increased survivability, develops a real-time picture of the theater battlespace, and enables the aircraft to quickly share information on short notice (target changes). In addition to a localized capability, the B-1’s datalink will include BLOS capability increasing flexibility essential to attacking time-sensitive targets.
B-1 Radar Upgrade is a candidate Long Term Upgrade that would improve the current Synthetic Aperture Radar resolution from three meters to one foot or better, allowing the B-1 to more autonomously and precisely Find, Fix, Target, Track, Engage, and Assess enemy targets with guided direct-attack or standoff munitions (JDAM/JSOW). Finally, the upgrade would replace older components that will be difficult to maintain due to obsolescence and vanishing vendors.
The B-One Next Enhancement (BONE) effort will include the integration and responsibility for future enhancements or improvements to the B-1 weapon system. The B-1 System Program Office (ASC/YD) announced in January 2001 that it contemplates awarding a single over-arching contract for acquisition and sustainment of the B-1 weapon system. The contract may include level of effort and discrete tasks for enhancement and sustainment activities to support product support, sustaining engineering, software support, technical data, Diminishing Manufacturing Sources (DMS) support, initial spares and support equipment as well as enhancements or improvement efforts for upgrades to the weapon system.
The Government cannot predetermine at the project level the precise B-1 aircraft acquisition and sustainment requirements or improvements to be acquired. Enhancements/upgrades/acquisitions may include, but not limited to, development and production of cockpit display upgrades, integrated Link 16, beyond line of sight UHF SATCOM datalinks, radar upgrades, vertical situation display replacement, gyro stabilization system upgrade, on-board diagnostics hardware upgrade, electro-multiplexing system upgrade, automatic test system upgrades, GATM upgrades, GPS modernization, ALQ-161A reliability and maintainability upgrades, defensive system upgrade, computer avionics upgrade, weapon integration upgrades, conventional bomb modules 1760 conversion upgrades, mission planning system upgrades/conversions, IFF system upgrades, digital flight control (including central air data computer) enhancement, B-1 unique support equipment, and associated B-1 weapon system software changes.
The estimated maximum amount for the acquisition is anticipated to be $2.4 Billion. Anticipated award date was 01 March 2002 for a portion of the effort. This single over-arching contract for the weapon system will contain multiple contract types at the contract line item level (e.g., cost-plus incentive fee, firm fixed price, time & materials, etc.) to accommodate a wide range of potential tasks. Contract efforts are subject to FAR 52.232-18 availability of funds.
The requirements for this acquisition are further defined in terms of functions to be performed relative to the acquisition of upgrades and sustainment efforts for the B-1 weapon system. Sufficient capability to integrate B-1 weapon system must exist to perform at a minimum ALL of the following related tasks: Provide interim contractor repair on programmed and known/unknown non-programmed B-1 weapon system items identified for repair/modification. Product support requires the contractor to identify, evaluate and recommend solutions to resolve B-1 weapon system hardware and software technical and supportability anomalies, deficiencies, and problems. Integrate hardware modifications with software and testing to verify proposed engineering problem solutions. Provide software support efforts required to analyze software change requests, and field anomalies. Design, code, and test software changes (including block changes) to the B-1 aircraft weapon system and ground support systems. Included in this effort is the integration of the software with the B-1 weapons system to include administrative support, interface with flight test organizations, manufacture of firmware, and compliance with Air Force retrofit processes. Identify and evaluate impacts to AF Mission Planning Systems, B-1 Training System, and associated ancillary equipment include identifying and evaluating impacts to those systems resulting from air vehicle anomalies, field anomalies and software/hardware block changes. Develop, deliver and maintain B-1 system related technical data as required. At a minimum provide maintenance of the Paperless CDRL Delivery System (PCDS) for Government and B-1 training system prime contractor to access all B-1 program data electronically. Perform weapon system enhancements or improvement efforts to support at a minimum all B-1 weapon system upgrades including development, test, production, retrofit modifications and related Type 1 training.
The heart of the aircraft is the massive Wing Carry-Through Box, which is made of titanium. As well as supporting the wings it also has to carry and support the main landing gear, and it also carries about 9000 kg of fuel. The wing pivot pin is 430mm in diamter and weighs about 272 kg. Made of titanium, it is hollow and is carried on a two-race spherical bearing.
The wing is a conventional two-spar aluminium box structure, which also serves as a fuel tank. The wing fairing seal is similar to that used on the Tornado, with sliding "feathers" supported by an inflatable bag.
The fuselage is of conventional monocoque construction, with internal frames roughly every 250mm for its entire length. The wing-body blending provides space for fuel and avionics, produces lift and also reduces the aircraft's radar signature. Near the nose are two small Structural Mode Control System foreplanes. These are used to smooth out aeroelastic fuselage whipping, which can be severe in large aircraft at low level.
The B-1 has three fuselage bays, each 4.57m long. There is a removable bulkhead between the first and second bays to allow cruise missiles to be carried internally. The bay doors are made of composite materials.
When the B-1A was turned into the B-1B, several measures were taken to reduce the aircraft's radar signature. These included changing the main radar antenna and completely redesigning the engine intakes so that radar cannot illuminate the engine fan faces. The front and rear bulkheads were canted downwards so that radar pulses reach them at an oblique angle. RAM has been used extensively, in such places as the engine air intakes, the bulkheads, glove vanes, the wing fairings, and anywhere there is an angle which could trap and reflect back radar energy. B-1B RCS is classified, but is widely reported to be about 1/100th that of the B-52.
In the event of an ejection, the order is OSO, DSO, CO and finally the AC.
The F101 is a twin-spool turbofan with a bypass ratio of 2:1. It has nine high-pressure (HP) compressor stages driven by two low-pressure (LP) and one HP turbine stages. Its total pressure ratio is 27:1. The engine is 4.6m long and 1.4m in diameter, and weighs just under 2 tonnes.
The engines are housed in pairs in nacelles under the wing root. The aircraft can be safely controlled even if both engines in one nacelle fail, and single-engine operation is possible at light weights.
The engine air intake ducts were completely changed when the B-1B was created. Instead of a complex moving ramp, the B-1B has a plain intake with no variable ramp. The S-shaped duct contains baffles to disperse radar energy, and extensive use is made of radar-absorbing material in the duct.
B-1B fuel capacity is around 93 tonnes, held in eight tanks. The forward two weapons bays are also plumbed for fuel tanks. In order to prevent the aircraft's centre of gravity getting out of balance, the Fuel and Center of Gravity Management Subsystem (FCGMS) automatically pumps fuel around the tanks in response to a variety of data inputs. The FCGMS can also be run in manual mode, and in the event of CG limits being exceeded (which led to the loss of B-1A number two) the crew receives visual and aural warnings.
The B-1B can be air-refuelled by the boom method. The refuelling receptacle is forward of the cockpit.
The heart of the B-1B's avionic system comprises four redundant MIL-STD-1553 data buses, which control the routing of data around the various on-board systems. Vital to the efficient operation of the B-1B is the Central Integrated Test System (CITS). This constantly monitors and verifies the performance of the various parts of the system.
The OAS contains a total of 66 LRUs, including 4 IBM AP-101F central computers. and the complete system weighs 1300 kg. 20 kVA of power is needed to run it.
As part of the Block D upgrade, GPS receivers were installed both for aircraft and JDAM navigation.
The B-1B is equipped with an AN/ARC-164(V) VHF radio, AN/ARC-210 VHF/UHF radio, AN/ARC-190 HF radio, AN/ASC-19 AFSATCOM, AN/APX-101A IFF transponder and an AN/APX-105 rendezvous beacon.
The DAS is known by the Air Force as AN/ALQ-161. It is mostly concerned with electronic counter-measures, although some infra-red kit is included. The ALQ-161 has 120 separate items, which weigh about 2500 kg. When its full jamming capacity is utilised, it consumes roughly 120 kW of power.
The ALQ-161 is basically a passive listening system, only resorting to active measures when necessary. A lot of its operation is automated, but the Defensive Systems Operator is able to override the computer and delay the onset of jamming if circumstances warrant. The system is controlled by a single IBM AP-101F computer.
The B-1B also carries an AN/ALQ-153 tail warning radar.
Under the Block F Defensive Systems Upgrade Program the B-1B is being fitted with an ALE-50 Towed Decoy System. This will be towed hundreds of meters behind the aircraft and provide a more inviting target for missiles. The TDS will be deployed on operational aircraft from 1999.
TDS is an interim upgrade. From 2002 the full DSUP will be in use. This is a replacement for the ALQ-161 system, and incorporates the ALR-56M radar warning receiver and the Navy-developed IDECM jamming system, which includes a fiber-optic towed decoy (FOTD). DSUP will reduce the number of defensive system "black boxes" from 120 to 34, and reduce the weight of the aircraft by about 1800 kg.
In should be noted that although
each bay can carry a different weapon, weapon types cannot be mixed within
a bay.
Mk 82 (84)
The first conventional weapon to be cleared for use by the B-1 was the Mk 82 general-purpose gravity bomb. The basic Mk 82 is 1.68m long and 0.27m in diameter, and weighs 226kg. It has an explosive warhead is 87kg of Tritonal, Minol II or H-6, and is usually equipped with mechanical M904 (nose) and M905 (tail) fuzes, or the radar-proximity FMU-113 air-burst fuze.
A standard Mk 82 can be converted to a Mk 82 AIR retarded bomb by the addition of a BSU-49/B high drag tail assembly. The "ballute" air bag which deploys from the tail provides a high speed, low altitude delivery capability by quickly slowing the bomb and allowing the aircraft to escape the blast pattern.
The B-1B can also carry the Mk 62, which is a sea mine based on the Mk 82.
About 5000 Mk 82s were dropped by B-1Bs during Operation Allied Force between April 1st and June 20th 1999.
Mk 65 Quick Strike (12)
The B-1B can carry 12 Mk65 sea mines. This weapon weighs 1086kg and is 3.25m long and 0.74m in diameter.
CBU-87 (30)
The CBU-87 Combined Effects Munition contains 202 BLU-97/B combined effects bombs, which when released have a footprint of about 200 x 400m. The bomblets are effective against light armour, personnel and materiel. Each bomblet is approximately 20cm long and 6cm in diameter. The CBU-87 is 2.3m long and 0.4m in diameter, and weighs 431kg.
The ability to carry this weapon was added in the Block C upgrade. Full operational capability was reached in August 1997.
B-1Bs did not drop any CBU-97s during Operation Allied Force.
CBU-89 (30)
The CBU-89 Gator is an area-denial cluster weapon, containing 72 BLU-91/B anti-tank and 22 BLU-92/B anti-personnel mines. In this configuration it weighs just under 500kg. It is 2.3m long and 0.4m in diameter. The size of the minefield depends on the height that the weapon is released from, but it is typically 200 x 650m.
The ability to carry this weapon was added in the Block C upgrade. Full operational capability was reached in August 1997.
CBU-97 (30)
The CBU-97 Sensor-Fuzed Weapon contains ten BLU-108/B submunitions, each containing 4 armour-penetrating projectiles with infrared sensors to detect infrared targets. At a preset altitude a rocket motor fires to spin the submunition and initiate an ascent. The submunition then releases its four projectiles, which are lofted over the target area. The projectile's sensor detects a vehicle's infrared signature, and an explosively formed penetrator fires at the heat source.
The CBU-97 is 2.3m long and 0.4m in diameter, and weighs 420kg. It can cover an area of about 150 x 400m.
The ability to carry this weapon was added in the Block C upgrade. Full operational capability was reached in August 1997.
Joint Direct Attack Munition (24)
The B-1B is now cleared to carry the 2000lb GBU-32 Joint Direct Attack Munition (JDAM). This capability is being added as part of the Block D upgrade. JDAM is basically a tailkit that turns a 2000lb Mk 84 general purpose bomb or a BLU-109 penetrator bomb into a GPS-aided INS-guided precision weapon.
Seven B-1Bs had received the Block D mods by the time of Operation Allied Force, but the only JDAMs used during the operation were dropped by B-2s.
Wind Corrected Munitions Dispenser (30)
The next phase of the Conventional Mission Upgrade Program (CMUP) is Block E, which will add the Wind Corrected Munitions Dispenser (WCMD) and upgraded computers. These changes will allow CBUs to be delivered more accurately from higher altitude. Aircraft should start to be fitted with Block E in 2001.
AGM-154 Joint Standoff Weapon (16)
JSOW is intended to provide a low cost glide weapon with a standoff capability from 30km to 70km, depending on launch altitude. It is a launch and leave weapon that employs a tightly coupled GPS/INS navigation system for midcourse navigation and imaging infra-red and datalink for terminal homing.
JSOW is just over 3.9m long and weighs between 450kg and 680kg. Extra flexibility has been built into the missile by its modular design, which allows several different submunitions, unitary warheads, or non-lethal payloads to be carried. JSOW-A (AGM-154A) dispenses 145 BLU-97 combined-effects bomblets which are used to attack soft targets such as SAM sites or airfields. The JSOW-B (AGM-154B) dispenses 6 BLU-108 anti-armour submunitions.
JSOW timescale for the B-1 is not known at present.
AGM-158 Joint Air to Surface Standoff Missile (24)
JASSM is a precision cruise missile designed for launch from outside area defences to kill a variety of fixed and relocatable targets. After launch, it will be able to fly autonomously over a low-level, indirect route to the target area where an autonomous terminal guidance system will guide the missile in for a direct hit.
JASSM's midcourse guidance is provided by a GPS-aided inertial navigation system protected by a new anti-jam GPS null steering antenna system. In the terminal phase, JASSM is guided by an imaging IT seeker and a target recognition system that provides aimpoint detection, tracking and strike.
JASSM timescale for the B-1 is not known at present.
Numerous sustainment and upgrade modifications are ongoing or under study for the B-1B aircraft. A large portion of these modifications which are designed to increase the combat capability are known as the Conventional Mission Upgrade Program. In FY93, The Air Force initiated CMUP in FY1993 to improve the B-1’s conventional warfighting capabilities. The $2.7 billion CMUP program is intended to convert the B-1B from a primarily nuclear weapons carrier to a conventional weapons carrier.
The four-block Conventional Mission Upgrade Program will enhance the airplane's effectiveness as a conventional weapons carrier. Capability will be delivered in blocks attained by hardware modifications with corresponding software updates. CMUP Block C, fielded in August 1997, gave B-1Bs the capability to drop cluster bombs. Block D upgrades, fielded in December 1998, include JDAM capability, a new defensive system, a towed decoy, which will enhance the survivability of the aircraft, and a new communication/navigation system. CMUP Block E gives B-1Bs the capability to deploy wind-compensated munitions, Joint Standoff Weapons (JSOWs), and Joint Air To Surface Standoff Missiles (JASSMs). It is scheduled to begin operational service in 2002. CMUP Block F, a set of further improvements to the bomber's defensive system, will go into operational service in 2003.
Capability Enhancement:
THE NEW 10 CARRY CONVENTIONAL BOMB MODULE FOR THE THREE DIFFERENT CLUSTER BOMB UNITS (CBUs 87, 89, & 97):
The B-1B Conventional Bomb Modules
work on the "Gun Clip" concept. The CBM can be popped in and out of the
3 different bays. After the Computer Upgrade (see Block E) the B-1 will
be able to have different weapons in each bay.
CBU TYPES
ALL THREE CBUs LOOK THE SAME ON THE EXTERIOR (THE EXTERIOR IS A TACTICAL MUNITIONS DISPENSER aka TMD), IT IS WHAT SUBMUNITIONS (OR CLUSTERS OF BOMBS, ie CLUSTER BOMB UNITS) THAT ARE CONTAINED INSIDE THAT DIFFERENTIATES THEM
Capability Enhancement:
The B-1B Mission Planning System is comprised of the Air Force's Mission Support System (AFMSS) hardware and core software and a B-1B specific Aircraft/Weapon/Electronic (A/W/E) module. AFMSS consists of computer-based tools to help USAF aircrews conduct effective and timely pre-mission planning, materials preparation, and post-mission review for air training, exercise, and combat operations. The B-1B A/W/E module, when integrated with AFMSS, will enable the user to plan and validate missions, and produce mission materials for the B-1B. The B-1B Mission Planning System will become operational in FY98. AFMSS is under development by Lockheed Sanders, Nashua, NH. The B-1B A/W/E is under development by Logicon, San Pedro, CA. Both contracts are managed by the Electronic Systems Center (ESC/YV), Hanscom AFB, MA.
Capability Enhancement:
The Block
E element of the B-1B Conventional Mission Upgrade Program (CMUP) is comprised
of avionics upgrades and weapon integration programs designed to provide
the B-1B with high accuracy and precision guided weapons capabilities.
The avionics upgrade and weapon integration activities of Block E include
the Computer System Upgrade Program (CSUP) and the Wind Corrected Munitions
Dispenser (WCMD), Joint Standoff Weapon (JSOW), Joint Air-to-Surface Standoff
Missile (JASSM) Integration programs. Descriptions of each program follow
with additional links for more information on each new weapon capability.
The two existing Data Transfer Units (DTUs), currently located immediately behind the Offensive System Operator's (OSO) seat, will be replaced with two new Digital Transfer Devices (DTD) units which will interface with the new ACUs. The DTD units are used by the crew to transfer important route information and bomb coordinates from the ground mission planning computers to the bomber’s computers. The new DTD units will be installed in the Central Equipment Bay (CEB).
The primary
emphasis of the computer upgrade will be to minimize hardware changes to
the B-1B while enabling a significant cost reduction in the maintainability
of the software. As part of the CSUP program, the existing JOVIAL J3B2
software for the six original ACUs will be converted to Ada with simultaneous
re-engineering of the weapons delivery functionality within the Avionics
Flight Software (AFS). A critical aspect of CSUP is the incorporation of
a weapons flexibility capability. This provides the capability to carry,
jettison and launch up to three different weapons (different type in each
bay) on a single sortie – e.g. WCMDs in the forward bay, JSOWs in the mid
bay, and JASSMs in the aft bay.
The WCMD Integration element of Block E will provide improved weapons capability by adding the operational employment of the WCMD variants of the Cluster Bomb Units (CBU)-87, CBU-89, and CBU-97. The WCMD variants have been redesignated CBU-103, CBU-104, and CBU-105 respectively. The CBUs are converted to the WCMD variants with the addition of an inertially guided tail kit assembly. The weapon can be released from low and high altitudes and is designed to attack armored formation targets and soft targets day or night. WCMD will have MIL-STD-1760B class II subset electrical and signal interfaces.
WCMD will add lethality to the B-1B conventional weapons capability by improving high-altitude accuracy of Cluster Bomb Units (CBU). GPS position updates transferred from the aircraft to the CBU Inertial Navigation System (INS) provides inertial guidance corrections for ballistic and wind errors after release. WCMD will have a two-stage dispense/disperse system for accurate delivery of its complement of 72 BLU-91/B and BLU-92/B, 202 BLU-97B, or 10 BLU-108/B submunitions.
Ten WCMDs
can be dropped from the Seventy-Sixty Enhanced Conventional Bomb Module
(SECBM) located in each the three weapon bays for a total of 30 per bomber.
The MIL-STD-1760B connector (see Block D) will be used to transfer important
guidance information from the bomber to the weapon prior to release. The
drawings below depict the WCMD load configuration on the SECBM.
The JSOW (AGM-154) is a family of kinematically efficient, air-to-surface glide weapons in the 1,000 lb. class that provide standoff capabilities. The JSOW/BLU-108 (referred to as AGM-154B) will improve aircraft survivability with day and night, all weather, and standoff launch capability outside point defenses against a variety of land targets.
The AGM-154B is designed to impede the advance of armor vehicles by incorporating the BLU-108/B submunition into the JSOW baseline (AGM-154A) airframe. The JSOW is a launch and leave weapon that employs a tightly coupled GPS/Inertial Navigation System (INS). The B-1B aircraft will carry the AGM-154B JSOW to suspected target kill zones, based upon intelligence data, and the weapon will fly to a dispense point to achieve optimum pattern coverage for the BLU-108/B sub-munitions. The launch aircraft will be free for maneuvering immediately upon weapon release.
Four JSOWs
can be dropped from the Multi-Purpose Rotary Launcher (MPRL) located in
each the three weapon bays for a total of 12 per bomber. The drawings below
depict the JSOW load configuration on the MPRL.
The JASSM provides the B-1B a unique, adverse weather, autonomous "launch-and-leave," precision guided munition. JASSM is a low observable, highly survivable, subsonic cruise missile deigned to penetrate next generation air defense systems encountered en route to its assigned target. The missile enables the B-1B to standoff outside enemy area defenses. The weapon's precise attack capabilities enable JASSM to place high value, fixed relocateable point targets at risk while minimizing aircrew and launch platform exposure to enemy air defense systems.
Potential JASSM targets range from non-hardened above ground to hardened, shallow buried targets. The missile carries a 1000-pound class, hardened, penetrating warhead. The warhead's penetration capability is comparable to the BLU-109/B. The missile employs an imaging infrared seeker system to provide pinpoint accuracy. The missile's mid-course navigation and a back-up mode for terminal guidance is the missile's Global Positioning System (GPS)/inertial navigation system (INS). Future JASSM objectives include the integration of a cluster-type warhead; the ability to attack more deeply buried, hardened targets; and the ability to carry special warhead payloads.
Eight JASSMs can be carried on the Multi-Purpose Rotary Launcher (MPRL) located in each the three weapon bays for a total of 24 per bomber. However, currently not all eight can be powered up simultaneously. Work continues to maximize the number to be powered up simultaneously. The drawings below depict the JASSM load configuration on the MPRL from a frontal and side view.
The Towed Decoy System (TDS) provides an interim improvement in the survivability of the B-1B in a hostile environment until the Defensive System Upgrade Program is complete. The decoy is a repeater jammer that’s towed hundreds of feet behind the B-1B. The decoy lures enemy missiles shot at the B-1B away from the aircraft by providing a more inviting target to the missile. The major components of the Navy developed ALE-50 Towed Decoy System are a launcher, a controller, a display unit, and decoy. This modification will require the addition of two fairings to the tail section of the B-1B to house the launcher and decoys. The Towed Decoy upgrade delivered first three operational aircraft in January 1999. B-1B’s capable of deploying the ALE-50 towed decoy, were used for the first time in Operation Allied Force. The decoy was deployed on every mission flown. The TDS system proved to be highly effective in Operation ALLIED FORCE. The TDS program is well into production and will complete modification of the the entire B-1 fleet by FY04/FY05.
The Defensive Systems Upgrade Program (DSUP) is a major modification to the defensive system on the B-1B. It provides improved threat warning to the aircrew and enhances the survivability of the B-1B in a hostile environment. DSUP will replace the current defensive system, the ALQ-161, with the ALR-56M radar warning receiver and the Navy-developed IDECM radio frequency jamming system, which includes a fiber optic towed decoy (FOTD). This modification will reduce the number of defensive system "black boxes " from 120 to 34. This will reduce the weight of the B-1B approximately 4000 pounds. The program has started the test phase of the development effort with flight test scheduled to start in late FY01. A Milestone III production decision is scheduled for the first quarter of FY04.
Capability Enhancement:
HOW IT WORKS. The decoy is a repeater jammer that’s towed hundreds of feet behind the B-1B. The decoy lures enemy missiles shot at the B-1B away from the aircraft by providing a more inviting target to the missile.
Defensive Systems Upgrade Program - DSUP
HOW IT WORKS: The ALR-56M radar warning receiver detects, identifies, and displays the relative location of enemy radars so that the aircraft is provided continuous situational awareness. The IDECM jamming system uses a combination of onboard transmitters and the FOTD to deceive enemy radars and missile systems.
