The Department of Defense, through the Defense Logistics Agency (DLA) Aviation at Philadelphia, is seeking proposals for the procurement of 101 units of a linear valve, specifically NSN 7R-4810-014553707-QE, under a presolicitation notice. This procurement requires engineering source approval due to the flight-critical nature of the item, necessitating that only approved sources may submit proposals, as the technical data necessary for full and open competition is not available. Interested parties must provide detailed information regarding their qualifications and experience in producing similar items, and proposals must be submitted within 45 days of the notice, with contact inquiries directed to Casey Stock at (215) 737-0543 or via email at casey.stock@dla.mil.