B-1B Conventional Mission Upgrade Program (CMUP)
The B-1B achieved initial operating capability as a nuclear bomber in FY87. Starting in 1993, the Conventional Mission Upgrade Program (CMUP) marked the aircraft’s transition from a nuclear to a conventional role. Initial conventional load was limited to 84 Mark-82 500-pound general-purpose bombs. Block changes carried out under the CMUP have enhanced the aircraft’s capabilities as follows:
- Software upgrades to offensive and defensive systems (Block B).
- Capability to deliver CBU-87/89/97 cluster bombs (Block C).
- Communication system upgrades, addition of Global Positioning System navigation, and the capability to deliver the GBU-31 Joint Direct Attack Munition (Block D).
- Upgrade the computers for increased weapon flexibility and better supportability, and integrate Wind Corrected Munition Dispenser (WCMD), Joint Stand-Off Weapon (JSOW), and the Joint Air-to-Surface Standoff Missile (JASSM) weapons (Block E).
- Upgrade the defensive avionics suite by removing most of the existing AN/ALQ-161 and replacing it with an AN/ALR-56M radar warning receiver and portions of the Navy's AN/ALQ-214 Integrated Defensive Electronic Countermeasures (IDECM) system with a Fiber-Optic Towed Decoy (Block F). The Air Force wanted to replace most of the older AN/ALQ-161 system because it repeatedly breaks down, there was a shortage of repair parts, and maintenance costs were $50 million a year. The ALE-55 was still the preferred solution; however, due to the lack of demonstrated maturity of the ALE-55 during the first five B-1 flight test sorties, prudent risk management indicated a second option should be explored. The B-1B was supposed to dispense up to eight of the 18-inch decoys which emit an electronic signal intended to confuse enemy ground radar and draw an incoming missile away from the aircraft. By late 2002 BAE Systems had built about 250 decoys for testing and would produce up to 3,000 if the program entered production. Tests in 2001 and early 2002 showed decoys had difficulty dispensing properly from the aircraft or they prematurely severed from the fiber-optic lines that trail the aircraft. Flaws in the decoy system led to a December 2002 decision to cancel the five-year-old $900 million program. Efforts to fix these flaws had increased development costs by $175 million, or about 70 percent, and meant the first units would not be ready for combat until October 2007, 17 months late. That would be 14 1/2 years after the upgrade program was conceived. The B-1B Defensive System Upgrade Program was cancelled in December 2002 due to repeated cost and schedule over-runs. However, the AF continued to improve the B-1B's effectiveness through integration of new computers and advanced conventional weapons. Combined Developmental and Operational Testing (DT/OT) for the new computers completed in July, and dedicated operational testing completed in December 2002. Testing showed the computers met or exceeded all Key Performance Parameters and they were approved for full rate production in April 2003.
In addition to these block upgrades, the remaining capability enhancement planned for the B-1B under the CMUP is the integration of the JSOW and the JASSM.
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. 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.
Initial operational testing of the B-1B Block E identified shortfalls in weapon system effectiveness and suitability. Follow-on operational testing confirms fixes to these shortfalls are effective and suitable. This effort concluded with the completion of JSOW and JASSM integration operational testing. Developmental flight-testing to integrate JSOW and JASSM weapon capability on the B-1B began in March 2003. Operational testing began in December 2003 and concluded in August 2004. The program combined developmental and operational testing and evaluation with a small, independent operational test and evaluation phase to confirm the results of the combined developmental test/operational test. Scheduled events consisted of JSOW and JASSM separation test vehicle performance and the transfer of targeting data to JSOW and JASSM captive flight vehicles.
The B-1B employed full and multiple bays of captive-carried JSOW and JASSM weapons as part of realistic operational testing. The release of a representative load of the qualified inventory of B-1B Block E weapons also occurred to ensure JSOW/JASSM integration software had not degraded fielded accuracy capability. The confirmation phase concluded with the release of a guided JSOW and JASSM weapon as well as the release of the 2,000-pound variant of JDAM, and both the CEM and SFW variants of the Wind-Corrected Munitions Dispenser.
Operational testing confirmed shortfalls identified during B-1B Block E IOT&E by 2004 were effective and suitable. However, false target generation in the Interleaved Search and Track mode of the radar and false failure indications produced by the on-board diagnostic system continue. Operational testing also confirmed that the B-1B is effective and suitable when employing the JSOW, the JASSM, the 2,000-pound variant of the JDAM, and both the CEM and SFW variants of the Wind-Corrected Munitions Dispenser. Fielded accuracy of representative loads carried by the B-1B during JSOW and JASSM integration operational testing also meet requirements. The B-1B LFT&E program for Block D identified a number of vulnerabilities to threats. These baseline vulnerabilities are also in Block E. However, there is no significant increase in vulnerability due to the addition of B-1B Block E-unique equipment.
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