Lockheed C-130 Hercules

For more than 40 years, Lockheed's C-130 Hercules -- with its large, unobstructed cargo hold and powerful turboprop engines -- has served as the backbone of many an air force's transport commands.

First flown in 1954, the C-130 began military service the following year, and went on to make a significant contribution to U.S. military efforts in Vietnam.