Blimps had their heyday between World War I and World War II, and since then, they've more or less been left behind by the airplane. Some things, though, blimps are just plain better at, and the Army is getting ready for the first flight of their "Long Endurance Multi-Intelligence Vehicle," aka "spy blimp."

The United States has the F-22. Russia has the Sukhoi T-50. And now, a series of recent pics shows that China has begun testing a second prototype of its own fifth-generation stealth aircraft, the Chengdu J-20.

Flying aircraft carriers are staples science fiction and steampunk. It's an idea that sounds like it would be completely crazy in reality, but it's not crazy enough to keep the Air Force commissioning a report on the idea from Boeing back in 1973.

Ten years ago, Boeing was trying to figure out whether the next step in air travel was increased speed or increased efficiency. The 787 Dreamliner should clue you in to what the decision was, but the increased speed option is not entirely off the table, and a new patent filed just last month might mean that Boeing's "Sonic Cruiser" is still alive and kicking.