Strong NASA influence on F-14 and F15

Here’s an interesting diagram showing 4 configurations studied in some detail by NASA in the FX program. Note the first two are similar to the F-14 and F-15, the third looks very like the Yak-45/47 and the fourth is basically the MiG-25. The main difference with the F-15 design is the cranked wing design of the NASA design, which was changed by McDonnell-Douglas due to transonic manouvering requirements.

From Partners in Freedom: Contributions of the Langley Research Center to U.S. Military Aircraft of the 1990s

http://techreports.larc.nasa.gov/ltrs/PDF/2000/spec/NASA-2000-sp4519.pdf