DAYTON, Ohio--The Air Force development of the Next Generation Adaptive Propulsion (NGAP) engine is not tied to the Boeing [BA] F-47 fighter, but instead to ensuring U.S. propulsion superiority, a service official said this week at the Air Force Life Cycle Management Center's annual industry days here. "From an air superiority-propulsion superiority perspective, the last fighter engine we pressed forward on was in the 1990s, so if we want to stay ahead of our competitors, then you have to lean…