Airline travelers already upset about shrinking seats and rising fees should steel themselves for a potential new cabin reality: listening to another passenger yakking on a mobile phone.

In a surprising and likely controversial step, U.S. aviation regulators on Thursday suggested they are leaning toward eventually allowing in-flight calls from airline passengers—with two important caveats: airlines will have the option of whether to provide the service, and passengers must be informed well in advance if the flight allows calls.

While the Transportation Department likely is years away from making a final decision, here’s why it is stepping up its review and a change could happen: calls on trains, buses and subways already are commonplace, and advances in onboard Wi-Fi—the technology enabling such calls miles above the Earth—are improving call quality.

The proposal won’t become final until agency officials analyze what is likely to be a torrent of public comments, many expected to be strongly opposed to calls in closed cabins. Airlines also could veto the move, and DOT could decide to ban all such airborne communications.

Some frequent fliers already are salivating at the prospect. “I’m going to start saving all my billing questions and help desk inquiries for the plane. My whole row can suffer with me on hold,” said Michael Greene, a Chicago-based sales specialist for GE Healthcare. “We’re all going to start learning a lot more about the people we get seated next to,” he said.