The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is seeking proposals for the repair and modification of heat exchangers, specifically NSN 7R-1660-014648900-EL, with a total quantity of 16 units required. This procurement is critical for maintaining aircraft air conditioning, heating, and pressurizing equipment, which are essential for operational readiness and safety. The government intends to solicit and negotiate with only one source under FAR 6.302-1, but all responsible sources may express their interest and capability to meet the requirement within 45 days of this notice. Interested parties can contact Thomas S. McLaughlin at (215) 697-2486 or via email at THOMAS.S.MCLAUGHLIN7.CIV@US.NAVY.MIL for further details.