Would you be willing to fly on a plane with no pilot?

The technology exists, even if no airline is currently thinking about trying it.

The tragic Germanwings crash in the Alps this week -- which allegedly was caused deliberately by the copilot -- raises the question: Would it make sense to fly planes without pilots?

Some experts say the answer is yes.

"Planes can already fly themselves," said Mary "Missy" Cummings, a former Air Force pilot, an engineering professor and director of the Humans and Autonomy Lab at Duke University.

"Pilots only spend 3 minutes per flight flying a plane anyway, and they don't really need to do that," she said. About 80% of plane crashes are caused by human error, she adds.

The U.S. military already flies Global Hawk drones, which are nearly the size of a the widely-used Boeing 737 passenger jets. And military data shows that drone flights crash less often than piloted flights, Cummings said.

But so far businesses working on drones are looking only at non-passenger uses, like making deliveries or taking aerial pictures.

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Fliers aren't ready for pilotless flights either, according to Cummings.

"People want a human as a pilot who shares their own fate," she said. "We also need a babysitter up front, both to monitor the automation and to take charge if there's an unruly passenger."

Pilotless passenger planes are therefore probably decades away, said John Hansman, an aeronautics and astronautics professor at MIT who heads up the division of humans and automation.

"It's not a technical issue, it's an issue of societal trust," he said.

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The potential cost savings means the idea won't go away, though. Airlines could save trillions of dollars over the life of their aircraft just by switching from a two-person flight crew to a single pilot, Cummings said.

Once there's only a single pilot aboard an aircraft, she said the planes will have to be able to operate without a pilot in case the pilot is incapacitated.

"You're going to need backup capability where a plane can be landed from the ground, or it lands itself," she said. And once that's in place, pilotless jets will be the next step, first for cargo jets, then eventually for passengers, she predicted.

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A pilotless plane is at risk of getting hacked. But experts say that hacking risk can be kept very small and will be worth the risk.

"Can it be hack proof. No never. Strongly hack resistant? Yes." said Todd Humphreys, a University of Texas professor of aerospace engineering. He says hacking poses less of a risk to fliers than a hijacker or rogue pilot.

Airlines will probably be able to convince passengers to board pilotless planes with lower fares, according to Cummings, who's conducted surveys about the issue.

"If people feel like it's a substantial savings, they're more willing to do it," she said.

And as people start getting comfortable with self-driving cars in the coming years, she expects attitudes towards pilotless planes to change also.

"People are getting more and more used to automation," Cummings said.