Published Reports

		Pre-Milestone A and Early Phase Systems Engineering: A Retrospective Review and Benefits for Future Air Force Acquisition (2008) The ability of U.S. military forces to field new weapons systems quickly and to contain their cost growth has declined significantly over the past few decades. There are many causes including increased complexity, funding instability, bureaucracy, and more diverse user demands, but a view that is gaining more acceptance is that better systems engineering (SE) could help shorten development time. To investigate this assertion in more detail, the US Air Force asked the NRC to examine the role that SE can play during the acquisition life cycle to address root causes of program failure especially during pre-milestone A and early program phases. This book presents an assessment of the relationship between SE and program outcome; an examination of the SE workforce; and an analysis of SE functions and guidelines. The latter includes a definition of the minimum set of SE processes that need to be accounted for during project development.
		Assessment of Wingtip Modifications to Increase the Fuel Efficiency of Air Force Aircraft (2007) The high cost of aviation fuel has resulted in increased attention by Congress and the Air Force on improving military aircraft fuel efficiency. One action considered is modification of the aircraft s wingtip by installing, for example, winglets to reduce drag. While common on commercial aircraft, such modifications have been less so on military aircraft. In an attempt to encourage greater Air Force use in this area, Congress, in H. Rept. 109-452, directed the Air Force to provide a report examining the feasibility of modifying its aircraft with winglets. To assist in this effort, the Air Force asked the NRC to evaluate its aircraft inventory and identify those aircraft that may be good candidates for winglet modifications. This report which considers other wingtip modifications in addition to winglets presents a review of wingtip modifications; an examination of previous analyses and experience with such modifications; and an assessment of wingtip modifications for various Air Force aircraft and potential investment strategies.
		Improving the Efficiency of Engines for Large Nonfighter Aircraft (2007) Because of the important national defense contribution of large, non-fighter aircraft, rapidly increasing fuel costs and increasing dependence on imported oil have triggered significant interest in increased aircraft engine efficiency by the U.S. Air Force. To help address this need, the Air Force asked the National Research Council (NRC) to examine and assess technical options for improving engine efficiency of all large non-fighter aircraft under Air Force command. This report presents a review of current Air Force fuel consumption patterns; an analysis of previous programs designed to replace aircraft engines; an examination of proposed engine modifications; an assessment of the potential impact of alternative fuels and engine science and technology programs, and an analysis of costs and funding requirements.
		A Review of United States Air Force and Department of Defense Aerospace Propulsion Needs (2006) Rocket and air-breathing propulsion systems are the foundation of future Air Force and DOD aerospace systems. Current conditions such as high fuel prices, growing costs for sustaining aircraft, a decreasing domestic launch capability, and uncertainties about future, domestic research personnel have intensified concerns about this propulsion base. To help assess this situation, the Air Force and DOD asked the NRC to evaluate the U.S. aerospace propulsion technology base to determine if current research efforts are likely to support future warfighter capabilities. This report presents an assessment of the existing technology base and the future Air Force capabilities that will need to be supported by that base; an analysis of gaps in technology needs; and recommendations for meeting future capabilities not yet fully defined with current science and technology development plans. The report covers air breathing technologies, rocket technologies for access to and in-space operations and for missiles, and cross-cutting technologies.
		Future Air Force Needs for Survivability (2006) A key technical issue for future Air Force systems is to improve their ability to survive. Increased use of stealth technology is proposed by many to be the major element in efforts to enhance survivability for future systems. Others, however, suggest that the high cost and maintenance required of stealth technology make increased speed potentially more productive. To help address this issue, the Air Force asked the NRC to investigate combinations of speed and stealth that would provide U.S. aircraft with a high survival capability in the 2018 period, and to identify changes in R&D plans to enable such aircraft. This report presents a review of stealth technology development; a discussion of possible future missions and threats; an analysis of the technical feasibility for achieving various levels of stealth and different speeds by 2018 and of relevant near-term R&D needs and priorities; and observations about the utility of speed and stealth trade-offs against evolving threats.

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