 From 1 April 1970 to 30 September 1992, the 4th Airborne Command and Control Squadron, assigned to the 28th Bombardment Wing at Ellsworth Air Force Base, South Dakota, provided airborne command post responsibilities with specially modified Boeing EC-135 airborne command post aircraft for Fifteenth Air Force and Strategic Air Command as part of the Post Attack Command and Control System The 4th was the workhorse of Airborne Launch Control System (ALCS) operations.Three dedicated Airborne Launch Control Centers (ALCC) (pronounced "Al-see"), designated ALCC No.1, ALCC No.