Airline passengers will give up leg room, overhead-bin space, and a healthy amount of dignity in exchange for a lower airfare. But many won’t give up human pilots.

A dilemma that sounds like it belongs in science fiction is one that some travelers may grapple with in the near future. “Technically speaking, remotely controlled planes carrying passengers and cargo could appear” by around 2025, the investment bank UBS said a report released Monday (Aug. 8). A switch to full automation could save the air-transportation industry $35 billion a year and cut passenger fares by around 10%.

Other benefits include allowing airlines go without increasingly hard-to-find pilots; rare, but unsavory human behavior, and even save on fuel that human pilots can waste.

Travelers aren’t on board yet. Only 17% of the 8,000 UBS surveyed said they would be likely to take a pilotless flight. “Perhaps surprisingly, half of the respondents said that they would not buy the pilotless flight ticket even if it was cheaper,” the researchers said.

Self-driving cars face less consumer resistance: A UBS survey in 2015 found 30% of people would be likely to ride in one. While some lawmakers are eager to get more self-driving cars on the road, autonomous vehicles will likely have many more physical obstacles to contend with in their paths than airplanes: hard-to-predict movements of pedestrians, altered street signs, and bikers.

Many functions of flight are already automated. Autopilot systems allow planes to cruise on their own. They can even land themselves. Modern planes are outfitted with sensors that relieve pilots from entering data into flight systems.

Boeing said is planning to test flights next year on which artificial intelligence will carry out some tasks handled by pilots. Pilots will still need to make quick decisions that autopilot systems may not be able to do, such as handling heavy turbulence. Boeing’s vice president for production development said in June that the automation wouldn’t be applied until it’s as adept at handling a mid-air crisis as captain Chesley Sullenberger. After a flock of geese knocked out the engines of a US Airways Airbus A320 shortly after takeoff in New York City, “Sully” landed the plane on water in “the Miracle on the Hudson.”

Over-reliance on automated systems could spell trouble for some pilots if those skills atrophy. A report on the Air France crash that killed 228 over the Atlantic in 2009 called for more manual training (paywall) for pilots after cockpit errors appeared to cause the Airbus A330 to stall.

UBS says fully automated aircraft could take to the skies as early as the mid-2020s, starting with cargo planes and air taxis. Fully automated commercial flight won’t likely take off until the 2040s, it says. It raises questions about security of the plane when the plane could be controlled remotely, and who would handle myriad unruly passengers

As UBS notes, technology isn’t the biggest hurdle—it’s convincing regulators and the public that autonomous planes will still fly safely.