The General Accountability Office (GAO) has told Congress that DoD needs a comprehensive cost and benefit analysis to better assess its tactical aircraft shortfalls. According to GAO, the continuing uncertainty surrounding the F-35 Joint Strike Fighter (JSF) and the low priority given to funding to maintain and upgrade legacy systems are the main challenges to DoD’s ability to meet future tactical aircraft requirements. Many in Congress have repeatedly expressed frustration with the rising costs of the aircraft acquisition program. Defense authorization committee leaders asked GAO to analyze DoD’s tactical aircraft requirements and focus on how the Navy and Air Force were addressing aircraft inventory shortfalls. GAO reviewed DoD’s requirements plan and essentially agreed with the set level of tactical aircraft. However, it expressed concern that the lack of a comprehensive cost and benefit analysis of the various program options make it much more difficult for DoD to determine the best mix of legacy and new aircraft, manned and unmanned. GAO acknowledged that DoD is still in the process of deciding how to adjust its long-term plan and program to conform to the changes in security assumptions identified in the 2010 QDR. However, it argued that decisions must be based on a clear and comprehensive analysis to develop the best approach. The report contained recommendations for Congress and DoD. It urged Congress to change DoD’s reporting requirements for future plans to include costs for “modernizing and sustaining legacy aircraft, including service extension programs.” It recommended that the Secretary of Defense should: 1) explain the “size and severity” of anticipated aircraft shortfalls; 2) provide the main assumptions for shortfall projections; 3) report the cost of potential alternatives to mitigate the shortfall; and 4) clearly state how the complementary capabilities of unmanned aircraft and other weapons systems are “accounted for and quantified.” Finally, GAO recommended that DoD include in its FY2012 budget plan a comprehensive comparison of the costs and benefits of extending the lives of legacy aircraft with those of buying new aircraft. The report also recommended that the budget plan include a technological and manufacturing feasibility assessment and the pros and cons in terms of combat capability for each option.