Navy R4D Skytrain airplane model. The C-47 Skytrain was the most commonly used transport in the Allied Air Forces and has operated in every theater of war. A version was even built under license by the Japanese (the Showa L2D), as well as by the Russians (the Lisunov Li-2). It was known under different designations (C-47, C-53, R4D) and different names (Skytrain/Skytrooper/Dakota/"Gooney Bird"), and by the civilian designation DC-3. DC-3B's taken over from airlines were given the military designations C-49 or C-84. A special staff transport model was designated C-117, but only seventeen were built. The C-47 was famous for its dependability, versatility, and ability to carry loads far heavier than the official specs allowed. Famous campaigns involving the C-47 were "flying the Hump" (transport over the Himalyas), dropping paratroops behind enemy lines on D-Day, and the post-war Berlin airlift. The C-47 was so useful that it was used by the U.S. military in WWII, Korea, and Vietnam, and many are still flying in different countries around the world today.