The USAF C-5 Galaxy Cargo Aircraft is larger than the C-17 Globemaster III. C-5's length is 247.1 feet (75.3 meters), wingspan is 222.9 feet (67.89 meters) and its height is 65.1 feet (19.84 meters).
C5 vs C17 via kwout
The C-17 measures 174 feet long (53 meters) with a wingspan of 169 feet, 10 inches (51.75 meters) and a height of 55 feet 1 inch (16.79 meters) .
The C-5 can also carry much more per flight than a C-17, as it's maximum cargo is 270,000 pounds (122,472 kilograms). C-17 can carry a maximum load of 170,900 pounds (77,519 kilograms) of cargo.
The C-5, the C-17 Globemaster III and the C-141 Starlifter are partners of AMC's strategic airlift concept. The aircraft carry fully equipped combat-ready military units to any point in the world on short notice then provide field support required to help sustain the fighting force.
The US Air Force is the world's premier aerial power. With 39 distinct types of aircraft, and many more subvarieties of each airframe, it is easy to understand why the US Air Force has no peers.