The Defense Logistics Agency (DLA) is seeking to acquire centrifugal fans and air purification equipment for CH-47 Chinook aircraft through an Indefinite Delivery Requirements (IDR) contract. The specific item required is identified by NSN: 4140-01-286-8852 and Part Number: 145DS210-6, with a production lead time of 300 days after contract award, excluding First Article Testing, and deliveries to Tinker AFB, Oklahoma. This procurement is restricted to pre-qualified offerors, including THE BOEING COMPANY, BOEING DISTRIBUTION SERVICES, INC., and MEGGITT DEFENSE SYSTEMS, INC., while other firms capable of producing the item are encouraged to seek source approval. Interested parties should submit requests via email to Rhondalyn Mack at rhondalyn.mack@dla.mil, including company details, Cage Code, and a telephone number, with foreign firms required to process requests through their respective embassies.