While the FAA, OEMs, and suppliers continue the complex work of determining exactly which aircraft and radar altimeter systems will be allowed to fly certain procedures in airspace that could have 5G C-band interference, reaction continued to yesterday’s announcement by Verizon and AT&T that they would once again delay switching on related transmitters near the nation’s busiest airports.
Verizon and the Federal Communications Commission (FCC) launched muted salvos aimed squarely at the FAA and aviation interests. Verizon wrote, “As the nation’s leading wireless provider, we have voluntarily decided to limit our 5G network around airports. The Federal Aviation Administration (FAA) and our nation’s airlines have not been able to fully resolve navigating 5G around airports, despite it being safe and fully operational in more than 40 other countries.”
FCC chair Jessica Rosenworcel said, “The FAA has a process in place to assess altimeter performance in the 5G environment and resolve any remaining concerns. It is essential that the FAA now complete this process with both care and speed.”
Meanwhile, airline interests and the NBAA praised the decision. Airlines for America (A4A) Nicholas E. Calio said, “We have not yet seen the details of the agreements. However, this pause provides the opportunity to ensure all stakeholders, consumers, and the U.S. economy are served in the long run.” NBAA president and CEO Ed Bolen said his organization “welcomed the decision by telecommunications providers AT&T and Verizon to temporarily delay transmitter deployments near certain airports in response to continued aviation industry concerns about potential 5G interference to radar altimeters.”
“It’s important that we get this launch right, and without any compromise to vital aviation safety systems,” Bolen said. “We appreciate the decision to defer deployment at certain towers, which will help ensure the ability to fly safely and efficiently across our National Airspace System.”
However, it remains unclear how long it will take aviation stakeholders to evaluate the performance of radio altimeters in a plethora of impacted aircraft and submit alternative means of compliance (AMOC) to the more than 1,500 related notams issued earlier this month by the FAA.
At a Helicopter Association International (HAI) webinar on 5G interference last week, Lockheed Martin technical fellow Nichola Kefalas warned that the FAA is engaged in a “first step” to “clear some of these restrictions for big swaths of aircraft fleets as quickly as possible. But it's going be a continuously evolving thing.” He said, “There's going to be a very wide range of different potential impacts and different levels of relief that can be obtained in this process. At some point, there is likely going to be a need for many [radar] altimeters to be retrofitted or replaced to improve performance and compatibility with 5G interference.”