This contrasts with statements made by Chief of Naval Operations Admiral Jonathan Greenert that their F/A-XX fighter might not be so focused on survivability as to sacrifice speed and payload. Unlike the previous F-22 and F-35 development programs that depended on new technologies that drove up cost and delayed introduction, the Air Force is intending to follow a methodical path of risk reduction to include as much prototyping, technology demonstration, and systems engineering work as possible before creation of an aircraft actually starts. Carlisle describes the sixth-generation strike capability not as just an aircraft, but a system of systems including communications, space capabilities, standoff, and stand-in options.[45]