B-2 Upgrades
The B-2 Bomber required low-level, terrain following performance. The B-2 includes a very complex Terrain Following/Terrain Avoidance (TF/TA) system that integrates 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 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).
Connectivity – DoD requires survivable communications media for command and control of nuclear forces. To satisfy the requirement, the Air Force plans to deploy an advanced Extremely High Frequency (EHF) satellite communications constellation. This constellation will provide a survivable, high capability communication system. Based on favorable results from a funded risk reduction study, the B-2 will integrate an EHF communication capability satisfying connectivity requirements.
Digital Engine Controller - The current analog engine controllers are high failure items, and without funding, ACC will be forced to ground aircraft beginning approximately FY08. Replacement of the engine controllers will 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 will need to be replaced with state-of-the-art processors. Although reliable, maintaining the present processors will become increasingly difficult and costly.
Signature Improvements - The B-2’s signature meets operational requirements against today’s threats. As advanced threats proliferate, it will be prudent to investigate advanced signature reduction concepts and determine if it is necessary to improve the B-2’s low observable signature.
Tactical delivery tactics use patterns and techniques that minimize final flight path predictability, yet allows 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 feetAGL, 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.
The Air Force is modifying the fleet of B-2 stealth bombers to carry new 500-pound satellite-guided GBU-30 Joint Direct Attack Munition (JDAM) bombs as soon as February 2003. The B-2 can carry 16 of the 2,000-pound satellite-guided bombs but could carry as many as 80 of the 500-pounders.
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 are 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.
The first of a series of planned upgrades to the B-2 Spirit Bomber entered flight test in FY03. This bundled package of capability includes the upgraded, or “Smart” Bomb Rack Assembly; ability to drop the 500 lb Joint Direct Attack Munition Mark 82; ability to drop the Enhanced Guided Bomb Unit-28 (EGBU-28) bunker buster; and addition of improved voice and data communication via integration of a programmable UHF satellite communication terminal. Incorporation of this upgraded package into the fleet began in FY04.
CANDIDATE LONG TERM UPGRADES BEYOND FY 15
The basis for the useful life of the B-2 includes data from initial Developmental Test and Evaluation analysis. Data indicates the aircraft should be structurally sound to approximately 40,000 flight hours using current mission profiles. Analysis further suggests that the rudder attachment points are the first structural failure item. The B-2 has not implemented an ASIP similar to the other bombers, and this makes it difficult to predict the economic service life and attrition rate. However, a notional projection, based on the B-52, predicts one aircraft will be lost each 10 years. This attrition rate, plus attrition due to service life, will erode the B-2 force below its requirement of 19 aircraft by 2027.
