From 1 April 1970 to 30 September 1992, the 4th Airborne Command and Control Squadron (ACCS), part of the 28th BMW, provided airborne command post responsibilities with specially modified Boeing EC-135 airborne command post aircraft for Strategic Air Command. The 4th ACCS 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. 2, and ALCC No. 3 were on ground alert around-the-clock providing ALCS coverage for five of the six Minuteman Intercontinental Ballistic Missile (ICBM) Wings. These dedicated ALCCs were mostly EC-135A aircraft but sometimes were EC-135C or EC-135G aircraft, depending on availability. ALCC No. 1 was on ground alert at Ellsworth AFB, SD and during a wartime scenario, its role would have been to take off and orbit between the Minuteman Wings at Ellsworth AFB, SD and F.E. Warren AFB, WY, providing ALCS assistance if needed. ALCCs No. 2 and No. 3 were routinely on forward deployed ground alert at Minot AFB, ND. During a wartime scenario, ALCC No. 3's role would have been to take off and orbit between the Minuteman ICBM Wings at Minot AFB, ND and Grand Forks AFB, ND, providing ALCS assistance if needed. ALCC No. 2's dedicated role was to take off and orbit near the Minuteman ICBM Wing at Malmstrom AFB, MT, providing ALCS assistance if needed. The 4th ACCS also maintained an EC-135C or EC-135G on ground alert at Ellsworth as the West Auxiliary Airborne Command Post (WESTAUXCP), which was a backup to SAC's Looking Glass Airborne Command Post (ABNCP), as well as a radio relay link between the Looking Glass and ALCCs when airborne. Although equipped with ALCS, the WESTAUXCP did not have a dedicated Minuteman ICBM wing to provide ALCS assistance to.