EXPLAINER: Why airlines fear 5G will upend travel this week

The airline industry is raising the stakes in a showdown with AT&T and Verizon over plans to launch new 5G wireless service this week, warning that thousands of flights could be grounded or delayed if the rollout takes place near major airports.

CEOs of the nation’s largest airlines say that interference from the wireless service on a key instrument on planes is worse than they originally thought.

AT&T and Verizon plan to activate their new 5G wireless service Wednesday after two previous delays from the original plan for an early December rollout.

The new high-speed 5G service uses a segment of the radio spectrum that is close to that used by altimeters, which are devices that measure the height of aircraft above the ground.

Here is a rundown of the issue from The Associated Press.

WHOSE SIDE IS THE GOVERNMENT ON?

Both.

The Federal Communications Commission, which runs the auctions of radio spectrum, determined that C-Band could be used safely in the vicinity of air traffic. The FCC in 2020 set a buffer between the 5G band and the spectrum that planes use to resolve any safety concerns.

But Buttigieg and FAA Administrator Stephen Dickson, whose agency is responsible for aviation safety, saw a potential problem. On Friday, they asked AT&T and Verizon to hold off activating C-Band 5G near an undetermined number of “priority airports” while the FAA conducted further study.

HOW DID AT&T AND VERIZON RESPOND?

They dismissed the concerns. The wireless industry trade group CTIA notes that about 40 countries have deployed the C-Band strand of 5G without reports of harmful interference with aviation equipment.

But AT&T CEO John Stankey and Verizon CEO Hans Vestberg did offer to reduce the power of their 5G networks near airports, as France has done.

“The...