AT&T, Verizon give FAA another year to fix airplane altimeters

The Federal Aviation Administration (FAA) today has struck an arrangement with Verizon and AT&T related to their use of C-band spectrum around airports. The main point is that the wireless carriers will give the FAA another year to solve problems with airline altimeters on major airlines.

“We believe we have identified a path that will continue to enable aviation and 5G C-band wireless to safely co-exist,” said Acting FAA Administrator Billy Nolen, in a statement. “We appreciate the willingness of Verizon and AT&T to continue this important and productive collaboration with the aviation industry.”

The parties will take a “phased approach” that requires operators of regional aircraft with radio altimeters most susceptible to interference to retrofit them with radio frequency filters by the end of 2022.

“This work has already begun and will continue on an expedited basis,” said Nolen.

At the same time, the FAA has been working with the wireless carriers to identify airports around which their service can be enhanced with the least risk of disrupting flight schedules.

AT&T and Verizon had offered to keep certain mitigations in place until July 5, while they worked with the FAA to better understand the effects of 5G C-band signals on sensitive aviation instruments.

“Based on progress achieved during a series of stakeholder roundtable meetings, the wireless companies offered Friday to continue with some level of voluntary mitigations for another year,” said Nolen, giving mainline commercial airlines until July 2023 to install filters or other enhancements to their altimeters.

An AT&T spokesperson, provided the following statement, “Through close coordination with the FAA over the last several months, we have developed a more tailored approach to controlling signal strength around runways that allows us to activate more towers and increase signal strength. Though our FCC licenses allow us to fully deploy much-needed C-Band spectrum right now, we have chosen in good faith to implement these more tailored precautionary measures so that airlines have additional time to retrofit equipment. We appreciate the FAA’s support of this approach, and we will continue to work with the aviation community as we move toward the expiration of all such voluntary measures by next summer.”

Nolen said radio-altimeter manufacturers have worked at an unprecedented pace with Embraer, Boeing, Airbus and Mitsubishi Heavy Industries to develop and test filters and installation kits. Customers are receiving the first kits now. In most cases, the kits can be installed in a few hours at airline maintenance facilities.

“Throughout this process, the FAA will work with both industries to track the pace of the radio altimeter retrofits while also working with the wireless companies to relax mitigations around key airports in carefully considered phases,” said Nolen.