The Department of Defense, specifically the Department of the Navy through NAVSUP Weapon Systems Support, is seeking proposals for the repair and modification of a heat exchanger (NSN 7R-1660-011046489-H1) critical to aircraft air conditioning and heating systems. The procurement involves a quantity of 40 units, with delivery terms set to FOB origin, and requires engineering source approval to ensure the quality and reliability of the parts, as they are flight critical. Interested vendors must be approved sources or provide necessary documentation for source approval, as outlined in the NAVSUP WSS Source Approval Information Brochures, and must submit their proposals within 45 days of this notice. For further inquiries, interested parties can contact Gerard T. Weiss at GERARD.T.WEISS.CIV@US.NAVY.MIL.