The new 5G C-band wireless broadband service expected to rollout on 5 January 2022 in the US will disrupt local radio signals and make it difficult for airplanes to land safely in harsh weather conditions, according to the Federal Aviation Administration.
Pilots rely on radio altimeter readings to figure out when and where an aircraft should carry out a series of operations to prepare for touchdown. But the upcoming 5G C-band service beaming from cell towers threatens to interfere with these signals, the FAA warned in two reports.
Flights may have to be delayed or restricted at certain airports as the new broadband service comes into effect next year. The change could affect some 6,834 airplanes and 1,828 helicopters. The cost to operators is expected to be $580,890.
“Radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band),” the aviation regulator said in one document [PDF].
“[It will require] revising the limitations section of the existing airplane/aircraft flight manual to incorporate limitations prohibiting certain operations requiring radio altimeter data when in the presence of 5G C-Band interference.” It’s likely that airports that have or will have C-band base stations will be affected.
Rollout for AT&T so-called 5G+ technology and Verizon’s 5G Ultra Wideband platform has been slow. Both network carriers have agreed to delay deployment to give the FAA more time to deal with safety issues. The services were initially due to be up and running this month.
“Although the FAA has determined the operations immediately at risk are those requiring a radio altimeter to land in low visibility conditions, a wide range of other automated safety systems rely on radio altimeter data,” the FAA added. “Harmful interference to the radio altimeter could cause these systems to operate in an unexpected way.”
Flights to some destinations may not be available at certain times, depending on the weather, or they may be diverted more frequently. It’s unclear what changes the FAA will make yet; officials are still discussing the matter with the Federal Communications Commission as well as telcos, aerospace, and airline companies.
“The FAA believes the expansion of 5G and aviation will safely co-exist,” it said in a statement.
“The FAA is working closely with the Federal Communications Commission and wireless companies, and has made progress toward safely implementing the 5G expansion. We are confident with ongoing collaboration we will reach this shared goal.” ®