This is a presolicitation notice for the repair of two specific F-18 aircraft components, a signal data processor and a servo controller, under an FMS requirement. The work is currently sole source to Raytheon in McKinney, TX, as the only known approved source with full repair capabilities. However, the agency will consider capability statements, proposals, or quotations from other responsible sources. Any company that is not already a government-approved source must submit a detailed source approval request with their proposal, as these are flight-critical items. The notice warns that the source approval process is lengthy and that an award cannot be delayed pending the approval of a new source.