Summary: After 14 years of development and evolving mission requirements, including six years of flight testing, the Air Force has yet to demonstrate that the B-2 design will meet some of its most important mission requirements. GAO found that many important testing milestones have yet to be reached. For example, the flight test program is only half complete and changes needed to deliver 20 fully operational B-2s did not begin until July 1995. The flight tests and the modifications are scheduled concurrently, and significant and potentially costly deficiencies could be detected before the testing is completed. The test program is scheduled for completion by July 1997, but GAO believes that this deadline is overly optimistic. GAO estimates that the Air Force might need another 55 aircraft test months to complete the test program objectives as currently planned. The flight test program depends on timely delivery of effective integration software to enable the various B-2 subsystems to work effectively and enable the crew to carry out their missions successfully. In the past, B-2 integration software was delivered late, without all the planned capabilities, and with deficiencies that delayed the completion of flight testing. Software has been a source of development problems on other aircraft, such as the B-1 and C-17. After nine years of building the B-2 bomber, Northrop Grumman, the prime contractor, continues to experience difficulties in delivering B-2s that can meet the Air Force's requirements. For the most part, aircraft have been delivered late and with significant deviations and waivers.
