FAA issues guidance for Boeing aircraft amid Canada 5G interference

The U.S. Federal Aviation Administration (FAA) has introduced new airworthiness directives that impose operating restrictions on aircraft lacking radio altimeter systems demonstrated to withstand Canada's updated 5G Lower C-band environment.

The directives became effective July 1, coinciding with Canada's removal of airport exclusion and protection zones that had previously helped reduce the potential for 5G interference with aircraft radio altimeters.

The FAA says radio altimeters installed on thousands of Boeing aircraft could be affected by wireless broadband operations within a specific section of the radio spectrum, known as the 5G lower C-band, potentially causing certain aircraft systems to malfunction.

To address the risk, the directives require airlines to revise existing flight manuals by adding limitations that prohibit certain operations relying on radio altimeter data while flying in Canadian airspace.

The FAA's latest action follows a dispute several years ago between the airline industry and wireless providers, including AT&T Inc. and Verizon Communications Inc., over the rollout of expanded 5G services.

As reported by the Financial Post, Transport Canada informed the FAA in March that, effective July 1, changes to the country's 5G safeguards—including the removal of airport exclusion and protection zones established by the Canadian government in 2023—“would result in a more severe 5G interference environment in the Canadian airspace.”

The FAA also said Boeing completed an analysis and, in May, “reported that certain airplane configurations will not demonstrate tolerance to radio altimeter interference in the new 5G environment in Canada.”

Model-specific directives

The FAA has adopted model-specific airworthiness directives covering several Boeing aircraft, including the 737 Classic and Next Generation series, older 747 models, the 747-8, the 777, and the 787.

The directive affecting the 787 is particularly significant because the FAA said inaccurate radio altimeter readings could prevent certain onboard systems from correctly switching from flight mode to ground mode after touchdown.

The FAA said Boeing advised the agency in May that some aircraft configurations within these fleets would not be able to tolerate Canada's revised 5G environment, leading regulators to issue aircraft-specific directives.

The new requirements do not prohibit airlines from operating flights to Canada, and the FAA has not reported any flight cancellations or schedule disruptions tied to the directives.

Rather, the operational impact will vary by airline and aircraft configuration. 

Boeing has not commented publicly on the issue just yet. 

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