 However, the Army Air Forces (AAF) was finding that standard military units like the 536th, based on relatively inflexible tables of organization were not well adapted to the training mission.Accordingly the AAF adopted a more functional system in which each base was organized into a separate numbered unit, whose manning and equipment was tailored to the base's mission.As a result of this reorganization, the 536th was inactivated, and along with other units at Muroc Army Air Field, California, replaced by the 421st AAF Base Unit (Bombardment Replacement Training Unit-Heavy).