UPDATE Despite aviation concerns about possible disruptions caused by wireless carriers now using 5G operations near airports, no major delays were caused by the technology over the holiday weekend, report several news outlets.
One of the biggest concerns had been whether 5G signals would interfere with aircraft radio altimeters that measure height above the ground that are critical when planes land in low visibility. Predictions that interference would cause massive flight groundings failed to come true last year, when telecoms began rolling out the new service. They then agreed to limit the power of the signals around busy airports, giving airlines an extra year to upgrade their planes, Inside Towers reported.
Transportation Secretary Pete Buttigieg recently told airlines that flights could be disrupted because a small portion of the nation’s fleet has not been upgraded to protect against radio interference.
Transportation Department Spokesperson Kerry Arndt described flight travel as being at “near-normal” levels over the weekend. But he also stressed that the FAA was “working very closely with airlines to monitor summer pop-up storms, wildfire smoke, and any 5G issues.”
Most of the major U.S. airlines had made the changes needed to adapt to 5G. American, Southwest, Alaska, Frontier and United say all of their planes have radio altimeters that are protected against 5G interference. The big exception is Delta Air Lines. Delta says it has 190 planes, including most of its smaller ones, that still lack upgraded altimeters because its supplier has been unable to provide them fast enough. “Some of our aircraft will have more restrictions for operations in inclement weather,” Delta said in a statement provided to CBS News. “Safety of flight will never be in question.”
Peter Greenberg, travel editor for CBS News, explained that potential disruptions have nothing to do with flyers’ personal phones, or whether those phones are in airplane mode. “Those don’t affect the navigation,” Greenberg said. “But a 5G tower can, because it’s sending a signal, not for the plane. But that signal can actually disrupt the readings you’re going to get on a radio altimeter, which could give the pilot a false altitude reading.”
Verizon and AT&T paid more than $80 billion combined at auction for their C-band licenses (3,700 MHz and 3,980 MHz) for their new 5G networks which are close to frequencies used by radio altimeters (4,200 – 4,400 MHz). However, because the frequencies are relatively close, FAA officials argued that harmful interference could result and potentially cause problems.
The FCC, carriers and FAA have been in talks over the issue. The rollout near airports was postponed until July 1 of this year. AT&T declined to comment. Verizon did not immediately respond to a question about its plans.
Transportation Secretary Pete Buttigieg reminded the head of trade group Airlines for America about the deadline in a letter last week, Inside Towers reported. He warned that only planes with retrofitted altimeters would be allowed to land under low-visibility conditions. He said more than 80 percent of the U.S. fleet had been retrofitted, but a significant number of planes, including many operated by foreign airlines, have not been upgraded.
By Leslie Stimson, Inside Towers Washington Bureau Chief