NASA uses two modified Boeing 747 jetliners, originally manufactured for commercial use, as Space Shuttle Carrier Aircraft (SCA).
The Northrop T-38 was used by the Air Force as a two-seat, supersonic trainer. This aircraft is used by NASA Dryden’s research pilots for proficiency and mission support flights.
NASA's single-seat F-16XL (ship #1), tail number 849, is stationed at Dryden Flight Research Center, Edwards, CA. It arrived at Dryden in March 1989, from General Dynamics in Fort Worth, TX
The F-15B research aircraft (tail number 837), the first two-seat F-15 built by McDonnell Douglas, was used initially for developmental testing and evaluation.