Upgrades

The B-2 Bomber required low-level, terrain following performance. The B-2 included a very complex Terrain Following/Terrain Avoidance (TF/TA) system that integrated the forward looking radar subsystem, flight control computers, navigational computers and cockpit displays. Before low-level flight testing could begin, the airworthiness of the system had to be reviewed and certified safe for flight. An Executive Independent Review Team (EIRT) was established to review the B-2 TF/TA system. The review team was made up of EN and Air Force Research Laboratory experts. EIRT engineers conducted a thorough review of the TF/TA system, primarily to make the system fail-safes more robust. The EIRT engineers also provided valuable lessons learned from previous aircraft systems such as the B-1, F-16 and F-111. The B-2 Program Office engineers, working with the contractor, implemented many of the EIRT recommendations. The organic engineering expertise of the EN EIRT and ASC Engineering Program Office engineers, along with the contractor team, combined to create a TF/TA system for the B-2 which has proven safe in both flight test and operational use.

Link-16 - Providing Line-of-Sight (LOS) data for aircraft-to-aircraft, aircraft-to-C2, and aircraft-to-sensor connectivity, Link-16 was intended as a combat force multiplier that would provide US and other allied military services with fully interoperable capabilities and greatly enhance 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).

Connectivity - DoD required survivable communications media for command and control of nuclear forces. To satisfy the requirement, the Air Force planned to deploy an advanced Extremely High Frequency (EHF) satellite communications constellation. This constellation would provide a survivable, high capability communication system. Based on favorable results from a funded risk reduction study, the B-2 would be modified to integrate an EHF communication capability satisfying connectivity requirements.

Digital Engine Controller - The current analog engine controllers were high failure items, and without funding, ACC would be forced to ground aircraft beginning approximately FY08. Replacement of the engine controllers was decided on to improve the B-2's performance and increase supportability, reliability, and maintainability.

Computers/Processors - With advances in computer technology and increased demands on the system, the B-2's computers were expected to need to be replaced with more advanced processors. Although reliable, maintaining the existing processors would become increasingly difficult and costly.

Signature Improvements - The B-2's signature met operational requirements against threats when it was deployed. As advanced threats proliferate, it was noted that it would be prudent to investigate advanced signature reduction concepts and determine if it was necessary to improve the B-2's low observable signature.

Weapon Systems - Tactical delivery tactics use patterns and techniques that minimise final flight path predictability, yet allow sufficient time for accurate weapons delivery. For conventional munitions. Bomb Rack Assembly (BRA) weapons delivery accuracies depend on delivery altitude. For a weapons pass made at 5,000 ft above ground level [AGL] or below, the hit criteria is less than or equal to 300 feet. For a weapons pass made above 5,000 feet AGL, the hit criteria is less than or equal to 500 feet. Similarly, Rotary Launcher Assembly (RLA) delivery of conventional or nuclear weapons (i.e. Mk 84, B-83, B-61) is altitude dependent. For a weapons pass made at 5,000 feet AGL or below, the hit criteria is less than or equal to 300 feet. For a weapons pass made above 5,000 ft AGL, the hit criteria is less than or equal to 500 feet. The hit criteria for a weapons pass made with GAM/JDAM munitions is less than or equal to 50 feet. As a result the Air Force engaged in a program to modify the fleet of B-2 stealth bombers to carry then new 500-pound satellite-guided GBU-30 Joint Direct Attack Munition (JDAM) bombs as soon as February 2003. The B-2 could carry 16 of the 2,000-pound satellite-guided bombs and as many as 80 of the 500-pound version.

In March 2002 it was reported that the Air Force had discovered cracks on the rear sections of 16 of the 21 B-2 stealth bombers. The cracks ranged in length from less than an inch to nine inches. They were all on titanium plates behind the jets' engine exhausts. The Air Force determined that the cracks did not pose an immediate danger to the B-2's, though maintenance crews were required to measure each of the cracks after every flight to see if they were growing.