The C-5 is a large high-wing cargo aircraft. It has a distinctive high T-tail, 25-degree wing sweep, and four TF39 turbofan engines mounted on pylons beneath the wings. The C-5 is similar in layout to its smaller predecessor, the C-141 Starlifter. The C-5 has 12 internal wing tanks and is equipped for aerial refueling. It has both nose and aft doors for "drive-through" loading and unloading of cargo. It has an upper deck seating area for 73 passengers and two loadmasters. The passengers face the rear of the aircraft, rather than forward. Its takeoff and landing distances, at maximum gross weight, are 8,300 ft (2,500 m) and 4,900 ft (1,500 m) respectively. Its high flotation main landing gear has 28 wheels to share the weight. The rear main landing gear is steerable for a smaller turning radius and it rotates 90 degrees horizontally before it is retracted after takeoff. The "kneeling" landing gear system permits lowering of the parked aircraft so the cargo floor is at truck-bed height to facilitate vehicle loading and unloading.