This is a solicitation for F139 engine cores (zero-time spare engines) to support the KC-46A aircraft fleet. The requirement includes a base quantity of 12 engines across three years and an optional quantity of 7 engines over two additional years, all priced on a firm-fixed-price basis. This acquisition is not set aside for small business concerns. The RFP incorporates provisions and clauses by reference, with delivery and acceptance terms specified in the attached document. Interested parties should contact the contracting officer for further information.