This document outlines a sole source federal contract opportunity for the overhaul of various cowling components for the F108 engine used in KC-135 aircraft. The solicitation is for the overhaul of left hand and right hand fan cowlings, inlet nose cowling, and left hand and right hand fan duct assemblies, with part numbers and national stock numbers provided. Delivery is required on a recurring schedule of every 75 days for each line item. The Boeing Corporation holds the previous contract for this work and is the sole source for this acquisition. The total estimated quantities to be purchased are outlined for each national stock number across multiple fiscal years. The contract will be awarded by the Department of the Air Force Materiel Command Lifecycle Management Center at Tinker Air Force Base.