The first flights with former USAF F-15D 79-0007, nowadays marked as N897NA and assigned to NASA Dryden were made at July 21st, 2011. NASA receive in total 3 F-15D's, all former 325nd FW aircraft, of which one will be used for spare sources.
Serial 78-0564 has serial N884NA allocated and 78-0565 N885NA. Both are not seen yet wearing this new registration.
Last may all three F-15's were seen by me at NASA Dryden still wearing their USAF markings, including "TY" code and fintip.
regards
Dennis Peteri
ps: don't want to start a discussion about civ/mil by posting this item in this topic.