FAA clears Boeing 777 and other planes after 5G warning halted some flights

The Federal Aviation Administration today said it has cleared 62 percent of US commercial airplanes to perform low-visibility landings at airports where AT&T and Verizon are deploying 5G on C-band spectrum this week.

Several international airlines previously canceled some flights to the US after Boeing issued a recommendation to not fly the 777 into airports where carriers are deploying 5G on the C-band. However, the 777 planes—or at least those that have altimeters capable of filtering out C-band transmissions—were on the FAA’s new list of cleared aircraft. The FAA has been granting Alternate Means of Compliance (AMOCs) to operators with altimeters that are safe to use.

“Airplane models with one of the five cleared altimeters include some Boeing 717, 737, 747, 757, 767, 777, MD-10/-11 and Airbus A300, A310, A319, A320, A330, A340, A350 and A380 models,” the FAA said in a statement issued shortly after 2 pm EST today. These airplanes are now authorized “to perform low-visibility landings at airports where wireless companies deployed 5G C-band,” the FAA said. The word “some” indicates that not every plane with the mentioned model numbers has an approved altimeter.

The 62 percent figure is an improvement over Sunday, when the FAA said it had “cleared an estimated 45 percent of the US commercial fleet to perform low-visibility landings at many of the airports where 5G C-band will be deployed on Jan. 19.” That first round of approvals included some Boeing 737, 747, 757, 767, and MD-10/-11 models as well as Airbus A310, A319, A320, A321, A330, and A350 models.

Canceled flights

Airlines that canceled some flights to the US include Emirates, All Nippon Airways, Air India, and British Airways, the Associated Press reported today. Some airlines switched to different aircraft on flights that were originally scheduled to use the Boeing 777.

“But Air France said it planned to continue flying its 777s into American airports. It did not explain why it didn’t change its aircraft as many other carriers have,” the AP wrote.

Major US airlines sent a letter to US government officials on Monday warning of “catastrophic disruption” to air travel and asked for a ban on C-band deployment within two miles of airport runways. AT&T and Verizon subsequently agreed to additional limits around airports.

Boeing warning

AT&T and Verizon are deploying 5G on C-band frequencies between 3.7 GHz and 3.8 GHz this year. The carriers spent a combined $69 billion on licenses to use spectrum between 3.7 GHz and 3.98 GHz, and they plan to use the upper part of those frequencies in future years.

The radio altimeters used to determine airplane altitudes rely on spectrum from 4.2 GHz to 4.4 GHz. While US carriers point out that 5G on the C-band has been deployed without problems in nearly 40 countries, the FAA and airlines say that some altimeters may not be able to filter out 5G transmissions.

“Boeing on Monday night sent a so-called multi-operator message to carriers flying 777 and 747-8s and ‘recommends operators do not operate 777 airplanes on approach and landing to US runways’ with 5G C-band notices starting on January 19 unless there is an alternative means of compliance with FAA directives,” according to a report yesterday by The Air Current.

Boeing declined to comment when contacted by Ars today. The FAA referred us to its new statement confirming that 62 percent of planes have been cleared.

The FAA on January 4 agreed not to seek any more 5G delays from AT&T and Verizon barring “any unforeseen aviation safety issues.”

“During the two-week delay in deploying new 5G service, safety experts determined that 5G interference with the aircraft’s radio altimeter could prevent engine and braking systems from transitioning to landing mode, which could prevent an aircraft from stopping on the runway,” the FAA said on January 14. The January 14 statement also said the FAA “will require operators of Boeing 787s to take additional precautions when landing on wet or snowy runways at airports where 5G C-band service is deployed.” The 787 was not on today’s updated list of planes that are authorized “to perform low-visibility landings at airports where wireless companies deployed 5G C-band.”

All of the FAA’s recent statements on 5G and altimeters are available at this page.

https://arstechnica.com/?p=1826976