The government is investigating how to make civilian airspace safe for uncrewed drones that are flown remotely. And once the technological problems are solved, it's only a matter of time and economics until passenger airliners fly without pilots on board.
These remotely piloted craft are known as uncrewed aerial vehicles, or UAVs for short. A major part of the US war effort overseas, they can only be operated in American airspace as long as the entire area has been confirmed clear of civilian aircraft. Intended to prevent collisions, the problem is that this lengthy clearance procedure severely limits what UAVs can do, pretty much ruling out any time-sensitive operations. Because UAVs only need a single remote pilot instead of an entire crew, and that remote pilot doesn't require training as extensive (and, therefore, as expensive) as that of his or her airborne counterparts, they are significantly cheaper to operate than crewed airplanes.
That's partially why the Federal Aviation Administration has asked a Boeing subsidiary and the New Jersey Air National Guard to figure out what it would take for UAVs and civilian aircraft to operate in the same space; the United Kingdom is also heading up a similar project dubbed Astraea 2. The major issues are how air traffic controllers could interact effectively with dozens of UAVs and maintain communication with their remote pilots, as well as the biggest concern of all: how to avoid collisions. There are solutions in the work involving an array of sensors and radar, although no one has yet come up with a failsafe in case the link with the remote pilot is severed.
These are major obstacles, but the benefits of overcoming them are enormous. UAVs would be a cheap way to expand border monitoring efforts, not to mention their applications in surveillance, search-and-rescue missions, and farming. But all of that is nothing compared to what UAVs could do to the cargo planes. The cargo airlines stand to save millions by switching from crewed planes to drones, and this change could happen as soon as the ban on UAVs in civil airspace is lifted.
The big question is whether we're headed towards remotely piloted passenger aircraft. There's no law requiring airliners to have a pilot, leaving open the possibility of a super-budget airline to offer massively cheap fares on a drone plane. (How cheap? Think $50 from New York to Los Angeles cheap.) After all, a lot of the actual work of flying today is done by the computer systems - what's the problem with just taking it one logical step further? The huge savings involved could make that a compelling argument, although you won't be catching me on one of these drones anytime soon.