We got lucky with the weather in Washington State. It's a clear afternoon with a few scattered clouds, low wind speeds--ideal flying conditions. Mike Dubbury's calm briefing helps, too. Honeywell's senior test pilot talks me through the upcoming trip in the Beechcraft King Air C90, which I'll be piloting. I can't quite relax, though.

Anthony Foxx waits for the countdown, then hits the plunger. The catapult releases its bungee cord, slinging the drone from to a standstill to 50 mph in half a second. The drone spins up its twin propellers and flies a few hundred feet up, circling overhead. "That's amazing," Foxx says, as the UAV drops its package within a few feet of the practice delivery zone, then belly flops onto a brown landing pad that resembles the base of a jumping castle. During the closing months of his four-year run as US Secretary of Transportation, Foxx has come to California on a fact finding mission.

There's a reason Tesla and its competitors use the term "autopilot" for their semi-autonomous cars: Aviation is way ahead of the auto industry when it comes to making machines handle themselves. And yes, the very latest Airbus, Boeings, and F35 fighter jets can pull all sorts of tricks to help the pilot. But the vast majority of the planes in the sky, military and civilian, still rely on humans pilot to manipulate the joysticks and pedals that move their flaps and ailerons. Now, the US Department of Defense says it can make those primitive aircraft, built around cables and pulleys, ready for the age of autonomy--and a robotic arm is part of the answer. Autonomy will prove a crucial feature of 21st century air transportation and warfare, but it's not the easiest thing to add to the current fleet.