The use of radio altimeters at airports will be banned by the FAA because of interference from 5G cellular technology.
The airworthiness directive was adopted ahead of the expected deployment of 5G wireless broadband networks by AT&T and Verizon in the C-Band spectrum, which had previously been allowed.
The broadband companies agreed to a one month delay of the deployment.
Radio altimeters are used to measure a plane's distance from the ground when flying at altitudes of 2,500 feet and below.
The FAA said that interference can be unsafe when pilots are undertaking instrument landings during conditions of limited visibility, though a wide range of other automated safety systems rely on altimeter data.
FAA deploys technology to reduce taxi times.
The agency is worried about interference because the C-Band spectrum is closer to the frequencies used by aircraft operators than the range occupied by current broadband technology.
The Federal Communications Commission auctioned off the newly allowed C-Band frequencies in February of last year. The move led to a bulletin from the FAA about the possible malfunction of radio altimeters.
The FAA rejected the offer of reducing power from their 5G towers for six months.
The FAA believes that the expansion of 5G can coexist with aviation.
The FAA is working closely with the FCC and wireless companies to make sure that the 5G expansion is safe. The agency is confident that they will reach the goal.
The APA praised the FAA's approach in a statement.
The APA believes that a lot of flight diversions would occur if the roll out goes ahead without implementing the necessary precautions. We don't want the passengers to experience this.
The FAA has not yet determined which airports are close enough to C-Band base stations for flight operations to be impacted by interference. The agency said it will use data from communications companies to make determinations and issue Notices to Airmen.
The use of enhanced flight vision systems for runway touchdown and instrument landing system approaches could be put on hold.
