The U.S. Air Force has ordered passenger seats for fifteen of its C-17 transports, at a cost of about $3,000 per seat. The C-17 can carry 102 passengers in its cargo bay (54 against the side and 48 down the centerline.) The seats fold up when not in use, and are designed for use by troops wearing parachutes, or not. When not in use, the seats are out of the way so cargo can stored normally. All the seat sets will be delivered by next year, and the air force has an option to buy another fifteen sets for the same price.