The B-29 heavy bomber not only dropped the first atomic bombs in 1945, but set many other aviation standards in subsequent years. Developing the B-29 was a tremendous engineering feat, and the project actually cost more than it did to create nuclear weapons. After World War II, the technology for the high flying, pressurized, four engine B-29 was used in several subsequent heavy bombers and transports. One was the C-97 strategic transport. From this aircraft came the first widely used jet transport, the Boeing 707 (many of which are still in use.) But one of the little known standards derived from the B-29 is the current 463L pallet system for goods moved by air. The 463L was initially based on the post World War II Department of Defense mobility bin. This, in turn, was based on the dimensions of the B-29 bomb bay.