PR# 49250123; NSN 2840-01-183-1908; Firm Fixed Price; Definite Quantity Contract; Unrestricted Acquisition; Other Than Full and Open Competition; The only approved manufacturing sources are Jet Avion, Cage 14236 and CFM International, Cage 58828;  Seal, Aft; Critical Application Item; Configuration Control Applies; Government FAT; Quantity of 3929 units; Inspection/Acceptance at Origin; FOB at Origin; Requested delivery is 450 days after receipt of order; Electronic Offers are not acceptable; Progress Payments are not offered as the conditions at FAR 32.5 have not been met; Any manufacturer, other than the approved source, wishing to submit a proposal on this item must submit a complete source approval package and a complete solicitation package; A copy of the solicitation will be available via DIBBS at https://www.dibbs.bsm.dla.mil/RFP on the issue date cited in this synopsis.  RFP's are in portable document format (PDF).  To download and view these documents you will need the latest version of Adobe Acrobat.  This software is available free at http://www.adobe.com.  A paper copy of this solicitation will be available to requesters.  The solicitation issue date is April 15, 2013.