Most travelers probably didn't give much thought to the security of airliner cockpits before the 9/11 attacks, and since then it might seem odd to some that cockpit doors are often left wide open ...

The F-35 Lightning II, the primary fighter jet of the U.S. military and its allies, can scream through the sky at up to Mach 1.6, or 1,200 miles per hour. It is literally impossible for today's pilots ...