5G C-band interference could take years to resolve
FAA administrator Steve Dickson warned the US house aviation committee in a panel hearing with the House Aviation committee FAA administrator Steve Dickson warned them that it could take several years to implement a permanent fix to the 5G C-band interference issue.
Back in April, 2021 the FCC auction off a new celular frequency range for use with the new 5G celular technology, this frequency range is called C-band. However neither the FCC or the FAA checked to see if this new frequency didn’t interfere with aircraft. They assumed it would not since they are different frequencies, but these frequencies sit very close together on the spectrum and as a result the aircraft’s radio altimeter receive mask produced interference with the C-band frequencies. This causes radio altimeter installed on aircraft to send incorrect readings, based on this the FAA issued a NOTAM (notice to air missions) indicating that approaches to airports where the C-band frequency was active would be restricted in minimum visibility weather where the radio altimeter is used.
The FAA conducted a study where it found which aircraft were prone to interference/inaccurate readings and is currently working on a fix for those aircraft that are affected. However FAA administrator Steve Dickson says that this is not fully reliable and while it is a good stop gap they should work on a permanent solution to this issue. He said the FAA is working with radio altimeter manufacturers, celular service providers and the RTCA to develop new radio altimeter standards, they hope to settle on these new standards early next year.
Dickson blamed struggle to issue an ever-growing list of alternative means of compliance (AMOC) approvals for aircraft, radar altimeters, and airports. There is more than 1,500 notams corresponding to C-band radar altimeter interference, he also pointed out the lateness with which the FAA received relevant data from the two most prominent 5G C-band wireless carriers, AT&T and Verizon.