ALPA ADVANCING AVIATION SAFETY AND SECURITY SINCE 1931

November 16, 2022

Changes to 5G Rules Are Needed to Protect Aviation


Earlier this year, C-band 5G mobile wireless companies activated transmitters that utilize spectrum in close proximity to the spectrum used by radar altimeters on aircraft. Since that time, airlines have been upgrading radar altimeters to improve their ability to tolerate interference. The FAA is strongly urging airlines to complete the updates by July 2023, so that aviation safety can be assured when mobile wireless goes to full power at that time. Aircraft that have not been upgraded will have severe operational restrictions placed on them. Additionally, the FAA has recommended slight changes to the Federal Communications Commission (FCC) C-Band rules to ensure that the mobile wireless industry’s use of 5G is compatible with the upgraded radar altimeters.

This week, ALPA joined many other aviation industry organizations in a letter that calls on the White House National Economic Council, FCC, National Telecommunications and Information Administration, Department of Transportation, and Department of Commerce to support the FAA’s recommendations. Read the letter.

The recommended changes include:

  1. Ensuring that antennas direct most of their power downward, away from aircraft flight paths;
  2. Requiring a lower unwanted emissions limit for 5G base stations in the band directly used by radar altimeters; and
  3. Mobile wireless working in cooperation with the FAA to modestly reduce power near key airports.

These changes would not significantly impact 5G operations and, in fact, are already being voluntarily followed by current mobile wireless deployments.

However, the FAA has also said that without permanent changes to the FCC’s 5G rules, the newly upgraded radar altimeters will still be inadequately protected, meaning that the current upgrade investments could be rendered useless. It would take years before radar altimeter equipment can be designed, manufactured, certified, and installed to meet the unrestricted transmission rules allowed by the current rules.

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