C-band 5G towers might affect thousands of planes in the US. According to a ruling by the FAA (Federal Aviation Administration) made on Tuesday, the new 5G bands used by AT&T and Verizon could interfere with a plane’s automatic landing systems, which are designed to work in weather conditions with poor visibility. The FAA is instructing 6,834 planes to not rely on their radio altimeters when landing in certain airports due to fear of 5G interference. A radio altimeter measures the height a plane is flying at and is used mostly during landing when the pilots can’t see the ground clearly.
FAA spokesman Lynn Lunsford gave the following statement regarding the ruling for The Verge:
“Landings during periods of low visibility could be limited due to concerns that the 5G signal could interfere with the accuracy of an airplane’s radio altimeter, without other mitigations in place. These limitations could prevent dispatch of flights to certain locations with low visibility, and could also result in flight diversions. We are engaged with the wireless operators, as well as our interagency partners, to do everything possible to make sure the mitigations are tailored to prevent disruptions.” – FAA spokesman Lynn Lunsford for The Verge
The FAA ruling states that airlines and pilots of the 6,834 planes deemed affected by the matter could prove on their own that their altimeters are protected and not going to be affected by 5G interference. This will allow the planes to fly as usual without altimeter restrictions.
AT&T and Verizon’s problematic mid-band is called C-band 5G. Of course, the whole purpose of building 5G towers with the band is better speed and coverage. However, the new band is more powerful and thus concerning to the FAA. C-band 5G and radio altimeters don’t operate on the same band, but the frequencies of the two are close enough to possibly interfere with each other.
A temporary solution proposed by Verizon and AT&T is to dial back the power of their 5G towers in proximity with airports for six months past the C-band launch. The launch itself was already pushed back by one month to January 2022.
The Verge states that a possible solution is to put a band filter on the radio altimeters, but organizations like the Radio Technical Commission for Aeronautics claim it will probably take years to certify and implement the filter in the planes.
