Special Notice: DEPT OF DEFENSE is seeking to procure HOUSING, MECHANICAL COMPONENTS for AIRCRAFT HYDRAULIC, VACUUM, AND DE-ICING SYSTEMS. This item, with part number 28004139-001, has National Stock Number (NSN) 1650-01-065-3474LE. The DEPT OF THE AIR FORCE, specifically the office FA8221 AFNWC PZBB, is responsible for this procurement.