 After thorough testing and modification of EC-135 command post aircraft, the ALCS demonstrated its capability on 17 April 1967 by launching an ERCS configured Minuteman II out of Vandenberg AFB, CA.Afterward, ALCS achieved Initial Operational Capability (IOC) on 31 May 1967.From that point on, airborne missileers stood alert with ALCS-capable EC-135 aircraft for several decades.