Left for San Antonio, the check-out and maintenance depot. According to AW&ST there is one unspoken for white tail still in the hangar there.
Two comments:
1. San Antonio is not a "check-out" facility. San Antonio does heavy maintenance and mods and do check-out only to ensure airworthiness immediately prior to final delivery to the customer.
2. Ship 272 is the only unsold C-17. It is stored
outside in a "preserved" state, not inside a hangar.