The C-141B Starlifter aircraft leaves four plumes of exhaust behind it as it prepares for an airdrop during Operation Deep Freeze. Starlifter can airlift combat forces, equipment and supplies, and deliver them on the ground or by airdrop, using paratroop doors on each side and a rear loading ramp. It can be used for low-altitude delivery of paratroops and equipment, and high-altitude delivery of paratroops. It can also airdrop equipment and supplies using the container delivery system. It is the first aircraft designed to be compatible with the 463L Material Handling System, which permits off-loading 68,000 pounds (30,600 kilograms) of cargo, refueling and reloading a full load, all in less than an hour. The C-141 has an all-weather landing system, pressurized cabin and crew station. Its cargo compartment can easily be modified to perform around 30 different missions. About 200 troops or 155 fully equipped paratroops can sit in canvas side-facing seats, or 166 troops in rear-facing airline seats. Rollers in the aircraft floor allow quick and easy cargo pallet loading. A palletized lavatory and galley can be installed quickly to accommodate passengers, and when palletized cargo is not being carried, the rollers can be turned over to leave a smooth, flat surface for loading vehicles. In its aeromedical evacuation role, the Starlifter can carry about 103 litter patients, 113 ambulatory patients or a combination of the two. It provides rapid transfer of the sick and wounded from remote areas overseas to hospitals in the United States.