How last week’s 5G deployment went so wrong

On Jan 28, 2022

Interviews with government and industry decision-makers, along with legal experts and public filings, reveal a divided federal bureaucracy with competing public mandates that clearly set the stage for a blowup. But they also paint the portrait of a US aviation regulator that missed a critical opportunity to present its case and potentially avoid this mess altogether.

The 5G-airlines crisis was mostly averted. Here's what happened - and what we still don't know

The core concern raised by aviation officials is that 5G — the ultra-fast cellular technology meant to pave the way for more smart devices and applications — could disrupt certain aircraft altitude sensors. Those instruments, known as radar altimeters, work by bouncing radio signals off the ground within a specific range of frequencies. But due to their design, many of them are also susceptible to interference from signals originating outside of those frequencies. According to aviation officials, 5G base stations operating in neighboring wavelengths could, depending on how they’re configured, potentially scramble aircraft computer systems and controls, and make it impossible to land in low-visibility conditions. (The dispute is exclusively about 5G infrastructure and has nothing to do with the 5G components in consumer cell phones. AT&T, one of the major wireless carriers with a big stake in 5G, owns CNN’s parent company.)

The Federal Aviation Administration told CNN it has been sounding the alarm about interference risks for years. The agency first raised concerns in 2015, as part of a filing to a United Nations coordinating body. Five years later, in the fall of 2020, the FAA also wrote to the Commerce Department calling for US telecom regulators to delay the rollout of 5G.

Finally, last month, the FAA issued a last-ditch warning that if 5G were switched on without more modifications, the agency would ban pilots from using radar altimeters near certain airports, leading to inevitable flight disruptions. That announcement kicked off weeks of frenzied negotiations between telecom and aviation officials around the holidays, culminating in last week’s showdown.

“This is one of the most delinquent, utterly irresponsible issues, subjects, call it what you like, I’ve seen in my aviation career,” Sir Tim Clark, president of Emirates, told CNN on Jan. 19. The next day, American Airlines CEO Doug Parker acknowledged on an investor call that the breakdown “wasn’t our finest hour, I think, as a country.”

Delayed signs are displayed on the flight schedule board at Ronald Reagan Washington National Airport in Arlington, Virginia, on January 18.

A slow-rolling crisis

In the debacle’s immediate aftermath, airline industry officials familiar with the late negotiations say that some of the pain could have been eased sooner had the Biden administration been able to fill key vacancies earlier at important agencies like the Federal Communications Commission.

The FCC declined to comment for this story but referred CNN to a statement last week by Chairwoman Jessica Rosenworcel, who urged the FAA to complete its ongoing review of aircraft radar altimeters “with both care and speed.” Rosenworcel, who had been serving in an acting…