Grumman X-29
McDonnell Douglas X-36
North American XB-70 Valkyrie North American XB-70 Valkyrie North American XB-70 Valkyrie General Electric YJ93-GE-3 afterburning turbojet ×6 General Electric YJ93-GE-3 afterburning turbojet ×6 North American XB-70 Valkyrie North American XB-70 Valkyrie
LTV XC-142A
Republic XF-84H Republic XF-84H
McDonnell XF-85 Goblin
Bell XV-3A
Hawker Siddeley XV-6A (P.1127)
Lockheed YF-12A Lockheed YF-12A
Northrop/McDonnell Douglas YF-23 Northrop/McDonnell Douglas YF-23 Northrop/McDonnell Douglas YF-23 General Electric YF120 General Electric YF120