Complex sentence: The Douglas C-133 Cargomaster was a large United States cargo aircraft built by the Douglas Aircraft Company between 1956 and 1961; 50 aircraft (32 C-133A and 18 C-133B) were constructed and put into service with the USAF.
Split into simpler sentences: The Douglas C-133 Cargomaster was a large cargo aircraft built by the Douglas Aircraft Company between 1956 and 1961 for use with the United States Air Force. Fifty aircraft (32 C-133A and 18 C-133B) were constructed and put into service with the USAF.