Heading into Saturday, one of the biggest concerns had been whether 5G signals would interfere with aircraft equipment, especially devices using radio waves to measure distance 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 telecom companies 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.
The leader of the nation’s largest pilots’ union said crews will be able to handle the impact of 5G, but he criticized the way the wireless licenses were granted, saying it had added unnecessary risk to aviation.
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.
Wireless carriers including Verizon and AT&T use a part of the radio spectrum called C-Band, which is close to frequencies used by radio altimeters, for their new 5G service.
The Federal Communications Commission granted them licenses for the C-Band spectrum and dismissed any risk of interference, saying there was ample buffer between C-Band and altimeter frequencies.
When the Federal Aviation Administration sided with airlines and objected, the wireless companies pushed back the rollout of their new service.
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 height-measuring devices, called 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.
The airline does not expect to cancel any flights because of the issue, Delta said Friday. The airline plans to route the 190 planes carefully to limit the risk of canceling flights or forcing planes to divert away from airports where visibility is low because of fog or low clouds.
FlightAware listed nine Delta flight cancellations Saturday. None of them were tied to 5G issues, according to the airline.
The Delta planes that have not been retrofitted include several models of Airbus jets: all of its A220’s, most of its A319’s and A320s and some of its A321’s.
The airline’s Boeing jets have upgraded altimeters, as do all Delta Connection planes, which are operated by Endeavor Air, Republic Airways and SkyWest Airlines, according to the airline.
JetBlue did not respond to requests for comment but told The Wall Street Journal it expected to retrofit 17 smaller Airbus jets by October, with possible limited impact some days in Boston.
In a compromise brokered by the Biden administration, the wireless carriers then agreed not to power up 5G signals near about 50 busy airports. That postponement ends Saturday.
More than 80% of the U.S. fleet had been retrofitted, but a significant number of planes, including many operated by foreign airlines, have not been upgraded.
This means on bad-weather, low-visibility days in particular, there could be increased delays and cancellations. Airlines with planes awaiting retrofitting should adjust their schedules to avoid stranding passengers.
Airlines say the FAA was slow to approve standards for upgrading the radio altimeters and supply-chain problems have made it difficult for manufacturers to produce enough of the devices.
Nicholas Calio, head of the Airlines for America, complained about a rush to modify planes amid pressure from the telecommunications companies.
Jason Ambrosi, a Delta pilot and president of the Air Line Pilots Association, accused the FCC of granting 5G licenses without consulting aviation interests, has left the safest aviation system in the world at increased risk.
Ultimately, we will be able to address the impacts of 5G.
Associated Press / ABC Flash Point News 2023.
What might not be known to those not conversant with Radio Frequency transmissions is that while the initial frequency is “just ” outside the range used by aviation there is what is known as Harmonics .
That is an initial doubling of the frequency at a lower transmission rate ,if this harmonic falls within the aviation range then interference occurs.