This is a sole-source solicitation for the repair of aircraft main slings (NSN 1730-014618330, P/N 74D115041-1001) to return them to Ready-for-Issue condition. Offerors must be approved sources or submit the required source approval data, and proposals must remain valid for at least 120 days. The work includes repair, testing, and inspection, and must be performed at the contractor's facility, specifically identified as The Boeing Company in St. Louis, MO (Cage 0PXV4). Contractors must comply with ISO 9001/AS9100 quality requirements and maintain a calibration system, with all parts and materials supplied by the contractor unless otherwise specified. Special repair determinations, such as Beyond Economical Repair or Missing on Induction, require DCMA/PCO coordination.