The U.S. Air Force is conducting market research to identify potential sources with the expertise, capabilities, and experience to qualify and overhaul the C-5 Center Door Gearbox and Rotar Actuator. The required security clearance level and amount of foreign participation have not yet been determined. Participation in this survey does not guarantee participation in future solicitations or contract awards, and the government will not reimburse survey participants’ expenses. Complete details, instructions, and the survey are provided in the attached “Sources Sought Synopsis.”