F-15B Eagle NASA ACTIVEF 15B ACTIVE NASA airplane model. The F 15 ACTIVE research aircraft, the first two seat F 15 built by McDonnell Douglas, was used initially for developmental testing and evaluation. In the mid 1980's, the aircraft was extensively modified for the Air Force's Short Takeoff and Landing Maneuvering Technology Demonstrator (S MTD) program. Those modifications included equipping the aircraft with a digital fly by wire control system, canards (modified F 18