We were flying east through the clear morning sky, easing the nose gently up toward 12,000 ft. above New Mexico. I was sitting in a Learjet's jump seat, wedged between two pilots with half a century of experience combined. There were no airplanes around for miles, and we were cruising smoothly along, as aviators say, "fat, dumb and happy." This is what flying today is supposed to be about--if you can make it through security.
Suddenly the plane jerked sideways--like a car getting rammed broadside. We began fishtailing, then rocking and then doing both at the same time. One wing dipped,...