 Between 1977 and 1992, a total of 68 E-3s were built.Because the Boeing 707 is no longer in production, the E-3 mission package has been fitted into the Boeing E-767 for the Japan Air Self Defense Forces.The E-10 MC2A was intended to replace USAF E-3s—along with the RC-135 and the E-8, but the E-10 program was canceled by the Department of Defense.