Modern airliners do a good job of flying automatically until something unexpected happens. At that point, a pilot takes control and typically resolves the problem with no drama or fanfare. Very rarely, though, a pilot must save the day or die trying. For passenger planes to fly autonomously, software would have to be capable of handling these edge cases.One day on a test range at Fort A.P. Hill in Virginia, two years ago, NASA researchers commanded a model airplane into an unstable flight mode as though it were encountering turbulence. After less than two seconds of porpoising up and down, the plane leveled off without any human intervention.

Autopilots on airliners fly through turbulence every day. What was different about this software was that researchers did not preprogram it with the aerodynamic model of the plane that would normally define how the autopilot should change thrust or the disposition of the plane’s flight control surfaces. Instead, researchers designed the software to rapidly figure out how to make the aircraft execute the appropriate pitch, roll and yaw maneuvers.

The software outperformed a human pilot who moments earlier tried but failed to level the plane off by remote control, the test organizers said.

This software, developed under a NASA aeronautics initiative called Learn-to-Fly, is just one example of the kind of research underway in the U.S. toward the vision of fully autonomous aircraft, someday potentially including passenger jets.