This growth resulted in two deployable squadrons being formed in 1978 from HM-12: HM-14 and HM-16. With this growth came the need for a separate fleet readiness squadron (FRS) to train crews and maintenance personnel. HiM-12 gave up its operational role and became the FRS for the airborne mine countermeasures community, as well as those squadrons flying the Sea Stallion in the VOD role.
In 1983, HM-12 acquired its first CH-53E Super Stallion helicopter for training purposes. The RH-53D also was retired in 1987, replaced by the larger MH-53E Sea Dragon. During Operations Desert Shield and Desert Storm (1990-91), HM-12 sent personnel to the combat zone, to augment other HM and HC squadrons.
In a consolidation move, HM-12 was disestablished on 30 September 1994. Its training role was assumed by Marine Helicopter Training Squadron 302 at Marine Corps Air Station New River, North Carolina, and the AMCM Weapon System Training School in Norfolk.