Current Air Force, Navy, and Marine Corps fighter/attack aviation aircraft are 1970s-vintage designs which will reach the ends of their service lives in the early part of the next century. While the Air Force is developing the highly-advanced F-22, it cannot be used to replace all current assets, especially F-16's, simply due to cost. A ''low-end'' complementary design is required, much as the F-16 was the ''low'' of a ''high-low mix'' with F-15's. The Navy's F-18 E/F will have improved characteristics compared to earlier versions, but it does not fully utilize newer technologies and specifically will not have the attainable levels of stealth and range-payload performance, nor will it offer next-generation STOVL capability for the Marines. RAND's Project Air Force conducted research into the tradeoffs in requirements specification for a next-generation attack fighter during the period from 1993 to 1995. As a part of that, this author developed and analyzed a representative notional design concept for a Next-Generation Attack Fighter (NGAF), then conducting trade studies of range, performance, payload, and technologies, followed by study of alternative approaches to attaining tri-service capability.