The Air Force began development of the B-2A in 1981 and reported on June 30, 1997, after 16 years, that the development and the initial operational test and evaluation had been completed. The Air Force reports of the initial operational tests were completed in November 1997. In 1986, the Air Force estimated that B-2A development could be completed for $14.5 billion, including a 4-year, 3,600-hour flight test program scheduled at that time to end in 1993. The flight test program ended June 30, 1997, and the estimated cost of the development program had grown to over $24 billion and the flight test program to about 5,000 flight test hours over 8 years. The development and testing programs were extended because of Air Force changes in the B-2 requirements and various technical problems. Major changes and problems contributing to the delays included (1) making the B-2A’s primary mission conventional rather than nuclear; (2) redesigning the aircraft to satisfy an added requirement to penetrate adversary air space at low altitudes; (3) difficulty in manufacturing test aircraft, resulting in late delivery of partially complete test aircraft; (4) difficulties achieving acceptable radar cross-section readings on test aircraft, which resulted in significant redesigning and retesting of certain components; and (5) correction of deficiencies in the aft deck structure because of the unanticipated effects of engine exhaust. Even though numerous problems hindered the scheduled completion of B-2A development, production began with no flight testing having been completed. This resulted in substantial overlap of development and production. Test and production aircraft were delivered that did not fully meet the Air Force requirements, and a 5-year post-delivery modification program was initiated to update all aircraft to the block 30 configuration. Since production began in 1986, the planned number of B-2As was reduced from 133 to 21 aircraft and both the total development and the average unit procurement costs increased. Table 1 shows the change in estimated total and unit cost from 1986 to 1998. The last two of the 21 B-2As were delivered to the Air Force in the block 30 configuration. The major effort remaining in the B-2A acquisition program is modification of the other 19 B-2As to the block 30 configuration, scheduled for completion in July 2000. Through April 1998, six B-2As have been delivered in, or modified to, the block 30 configuration and were operational at Whiteman Air Force Base, Missouri. Ultimately, the Air Force plans to have 21 B-2As, of which 16 will be available for missions (2 squadrons of 8 aircraft), and 5 will be in various maintenance and repair cycles. To test the operational performance of the B-2A, the Air Force measured B-2A performance against five broad operational objectives that were derived from documented Air Force operational requirements and concepts related to nuclear and conventional missions. Figure 1 identifies these operational objectives and the key elements of each that were included in the operational testing. Although test results indicate that B-2As generally met operational objectives, four deficiencies were identified during testing that will limit or, under some circumstances, change the planned concepts for using the B-2As and slow its operational pace. These relate to mission planning, defensive avionics, low observable materials, and deployment. As the B-2A matures, numerous minor problems identified in the test reports are scheduled to be corrected or improved based on their relative priorities. These include corrections of minor software and hardware deficiencies, improvements to make crew operations easier or faster, improvements of selected radar modes, and relocation of certain buttons or displays. The corrections and improvements involve flight operation as well as maintenance and support of the aircraft. Ground mission planning, which is still in development, is important to the successful employment of the B-2A because very precise mission routes must be planned to maximize the benefits of the aircraft’s low observable features. Mission planning for the B-2A, done with the automated Air Force Mission Support System (AFMSS), currently takes more time than planned. This will limit the Air Force’s ability to rapidly strike targets and sustain operations. The goal of the AFMSS development program is to produce a mission planning system that can provide specific B-2A mission plans in 8 hours. Testing as of June 30, 1997, concluded that the system frequently malfunctioned, was not flexible or user friendly, and was complex and time consuming to use. Air Force operators at Whiteman Air Force Base told us that the developmental version of AFMSS had so many failures that they estimated it would take 60 hours to plan a conventional mission and 192 hours to plan a nuclear mission. AFMSS is an acquisition program separate from the B-2A and is being developed to support all Air Force combat aircraft. Interface of AFMSS with the B-2A began in 1994. According to the operational test report, AFMSS is a complex system made up of separate subsystems developed by different contractors. The Air Force has received various developmental versions of AFMSS subsystems, and additional upgrades to software and hardware are planned in fiscal years 1998 and 1999. The Air Force expects these upgrades to support preparation of mission plans in 8 hours by the third quarter of fiscal year 1999. The Air Force spent over $740 million to develop the defensive system for the B-2A; however, test reports concluded that this system is unsatisfactory. The lack of an effective defensive avionics system could affect the B-2A’s survivability in selected situations because it is supposed to provide B-2A crews with information on the location of threats, both known and unknown that they may encounter during a mission. Limited funds and time are available to correct all the deficiencies in the defensive system. The Air Force plans some software upgrades that are intended to provide the defensive system with a limited but useful capability. Air Force officials said the cost of making the defensive system meet originally planned capability is unaffordable at this time. Air Force officials told us that all the functions originally planned for the system are not required to successfully carry out the planned B-2A missions. The operational test report further stated that, although the defensive system is rated unsatisfactory, the system’s deficiencies do not prevent planning and executing B-2A missions. The test report indicated that the B-2A’s low observability to adversary threat systems permits use of other effective tactics that could ensure its effective employment. The defensive system is supposed to provide the crew information on enemy threat systems to enhance B-2A survivability. Known threat locations are included in computer files prior to the mission. The system is to correlate these with the actual threats as the B-2A flies its mission, but it is also to identify and locate unknown threats that pop-up during a mission. However, this system does not work as planned, limiting the utility of information provided the crew during critical portions of expected B-2 missions. For example, test reports indicate that the defensive system provided inaccurate or cluttered information to the crew and had unacceptably high workloads for the operators. The number and significance of problems with the defensive system were not identified until near the end of the flight test program, leaving Air Force program managers little time to correct problems. Flight testing, where most of the problems were discovered, did not begin for the defensive system until February 1993, almost 4 years after the flight test program started in July 1989 and almost 2 years after other avionics began flight testing in June 1991. According to Air Force officials and an independent review team, several issues contributed to the deficiencies and their discovery late in the developmental and test processes. These reasons included (1) development and testing began late, (2) successful early laboratory tests could not be repeated in flight tests, (3) test results from flight tests were not completely analyzed before tests were continued, (4) the contract provided incentives to move ahead with development rather than correct problems, (5) there was too much confidence that upgrades to computer software would solve the problems, and (6) there were inadequate engineering controls to prevent the overoptimistic view and approach to this development effort. The Air Force’s cost estimate does not include the cost of correcting all deficiencies but does cover some improvements in the defensive system. The Air Force plans to develop software changes that are scheduled to be available for use by 2000, if tests demonstrate the changes are effective in providing a useful capability. Air Force officials indicated some changes have been tested by operational crews with good success. These software changes are intended to provide capabilities that are useful but less than were expected in the original defensive system design. The Air Force believes these changes will meet their requirements. To achieve the original design would require more costly upgrades, including new computer processors. Expensive hardware upgrades are not included in current Air Force plans to enhance the B-2A. Historically, defensive avionics have experienced significant problems during development. The B-1B bomber had serious deficiencies with its defensive avionics and the Air Force is still working to provide an effective defensive capability for the B-1B. Other defensive avionics programs, like the Air Force’s ALQ-135 jammer and the Navy’s Airborne Self-Protection Jammer, also experienced costly development problems. Low observable materials and features on the B-2A frequently fail, requiring high amounts of maintenance. They also have time-consuming and environmentally controlled repair processes and long cure times for the materials repaired. This reduces the time aircraft are available for operational use, which keeps mission capable rates below the Air Force requirement. These problems increase the amount of time it takes to prepare a B-2A for its next combat flight, potentially reducing the number of sorties that could be flown in a given period of time. During operational testing, low observable materials and features accounted for 40 percent of unscheduled maintenance and 31 percent of the maintenance hours to repair the aircraft.