FAA Enforces Radio Altimeter Upgrades for General Aviation Fleet Amid 5G Expansion
Thousands of general aviation aircraft operators are now facing a costly but critical compliance deadline. The Federal Aviation Administration (FAA) has finalized new regulations requiring radio altimeter upgrades. These are necessary to protect against interference from next-generation 5G Upper C-band wireless signals.
The FAA’s final rule was published on July 24, 2026. This followed the Federal Communications Commission’s (FCC) approval of a plan to auction 160 MHz of Upper C-band spectrum (3.98–4.14 GHz). This band is immediately adjacent to the 4.2–4.4 GHz range used by aircraft radio altimeters. The rule mandates the replacement or upgrade of approximately 58,500 radio altimeter units across roughly 40,700 aircraft nationwide.
For general aviation operators flying under Part 91, the compliance deadline is October 31, 2034. Commercial Part 121 airlines must comply by December 30, 2030. The total fleet-wide retrofit costs are estimated between $4.49 billion and $7.1 billion. Individual aircraft costs are expected to run between $80,000–$120,000. To ease the financial burden, eligible U.S. operators will have access to up to $2.2 billion in government-funded rebates. These are financed through FCC spectrum auction proceeds. The FAA projects that benefits from lifting operational restrictions will exceed $8 billion overall.
Radio altimeters are critical safety instruments. They measure an aircraft’s height above terrain and enable low-visibility takeoffs, autoland systems, and terrain awareness functions.