Do you remember a few months ago, the airline industry was up in arms about 5G cell service? The Brookings Institution had a headline in November saying, "Will 5G mean airplanes falling from the sky?" The Federal Aviation Administration objected to the Federal Communications Commission’s authorization of 5G networks on planes. Their concern was that the 5G radio signals would interfere with the radio altimeters used in automated aircraft landings. The airline industry also mimicked the broadcast industry, who have been saying for years that pirate radio stations would bring down planes by interfering with the radio reception in the controls. Anyone who listened to the radio might have been justified in scoffing at this argument, since there never has been a proven case of a pirate radio station bringing down an aircraft, nor did the expansion of 5G cell service onto planes in the United States this year cause any accidents. But, with more study, there might be something to this argument. It turns out that airplanes have been using really bad radio receivers. Poorly designed receivers were meant for an age before 5G, as the altimeters on some passenger planes fail to filter out signals from nearby spectrum, Politico reports. And there are poor radio receivers in all types of equipment in many industries, not just on planes. As new technologies such as driverless cars and telemedicine use additional bandwidth, the old timey radio receivers in the new technology can't cope. As a result, “large amounts of valuable spectrum lie fallow, spectrum reallocations are contentious, and users of spectrum lack legal certainty,” the office of Republican FCC Commissioner Nathan Simington said in a statement. His Democratic colleague, Jessica Rosenworcel, the FCC Chair, agrees. “If we want to be efficient, we also have to think about the other end. We have to think about receiving.” Last week the FCC commissioners voted unanimously to open an inquiry into the issue. They might embrace voluntary receiver standards, to get companies to upgrade their gear, or they could impose more controversial regulatory mandates. About 20 years ago the commission explored, but decided against, setting standards for all sorts of radio receivers to withstand interference from cell phone signals. Of course, the industries' business sides do not want any regulations, and some corporations are now saying the FCC does not have the authority to regulate receivers. David Grossman, vice president of regulatory affairs at the Consumer Technology Association, says, “Congress has not ever explicitly outlined FCC authority around regulation of receivers.” The FAA, after the 5G implementation, is now also considering developing new standards for radio altimeters, according to then-Administrator Steve Dickson at a House of Representatives hearing in February. “At some point you just get more and more and more people, and more and more and more services, in this spectrum; you just can’t do it,” said former FCC official Dale Hatfield, who is now executive fellow at the Silicon Flatirons Center at the University of Colorado at Boulder. “You’ve got to begin to take up on receivers. It’s inevitable.”