If you flew from Seattle to Tokyo today, you would spend just under 10 hours in the air. But in 1924, it took three U.S. Army planes 46 days to make the same trip — and many didn't even make it, crashing into a mountain in Alaska. Each leg of this journey contains enough adventure and hardship for an entire book. The fliers faced snowstorms, crocodiles, wild winds, illness and engine failure. One of the planes, the Chicago, can be seen at the Smithsonian Air and Space Museum, its days of dodging icebergs long over.