Final answer:
The maintenance release used to approve a major repair for RTS must be signed by the director or manager of the repair station.
Step-by-step explanation:
The maintenance release used by a repair station to approve a major repair for RTS must be signed by the person who has the authority to do so. Typically, this would be the director or manager of the repair station. Their signature on the maintenance release indicates that they have reviewed and approved the repair work, ensuring it meets the necessary standards and regulations.