|Assessment of Wingtip Modifications to Increase the Fuel Efficiency of Air Force Aircraft
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
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.