WASHINGTON, D.C. — In a definitive move to resolve the years-long friction between aviation safety and telecommunications expansion, the Federal Aviation Administration (FAA) issued a sweeping proposal on January 5, 2026, that will require the U.S. aviation industry to replace or upgrade nearly 58,600 radio altimeters.
The price tag for this massive technological overhaul is estimated at $4.49 billion, a figure that underscores the high stakes of managing the nation’s radio spectrum. The directive follows the signing of the “One Big Beautiful Bill Act” in July 2025, which mandated the auction of the “Upper C-band” for next-generation 5G services—a frequency range dangerously close to those used by critical aircraft sensors.
The Safety Mandate: Why Altimeters Matter
Radio altimeters are the unsung heroes of the cockpit, providing precise height-above-ground data that feeds into almost every major safety system on an aircraft.
- Critical Phases of Flight: These sensors are essential during low-visibility landings, allowing automated systems to handle descent, flare, and touchdown safely.
- Integrated Safety Systems: Data from altimeters informs Terrain Awareness and Warning Systems (TAWS), Traffic Collision Avoidance Systems (TCAS), and wind-shear detection.
- The 5G Threat: Current altimeter designs were developed before the advent of high-powered 5G signals. Without hardware upgrades, these sensors can “bleed” into neighboring frequencies, leading to ghost alerts or, more dangerously, a complete failure to detect the ground during landing.
The Billion-Dollar Breakdown
The FAA’s Notice of Proposed Rulemaking (NPRM) affects over 40,000 aircraft and nearly 14,000 operators across the commercial and private sectors. The agency has laid out a phased compliance timeline to manage the financial and logistical burden.
| Sector | Estimated Cost | Number of Aircraft Affected |
| Part 121 (Commercial Airlines) | $1.36 Billion | ~7,500 |
| Part 91 (General Aviation) | $1.58 Billion | ~26,000 |
| Part 129 (Foreign Carriers in US) | $891 Million | ~2,500 |
| Part 135 (Charter/On-Demand) | $651 Million | ~4,800 |
Total Estimated Impact: $4.49 Billion
Timeline for Compliance
The FAA has proposed two major milestones for the industry. Unlike the “stop-gap” measures seen in 2023, these deadlines are intended to be permanent solutions.
- Initial Milestone (2029–2032): Commercial air carriers (Part 121) and large foreign operators (Part 129) must meet new “interference-tolerant” standards by the date the FCC officially authorizes wireless services in the Upper C-band.
- Final Milestone (2031–2034): All remaining equipped aircraft, including general aviation and smaller charter fleets, must comply within two years of the initial deadline.
The “Who Pays?” Controversy
The announcement has reignited a fierce debate over financial responsibility. While the aviation industry argues that the “polluter” (the telecommunications companies) should pay for the retrofits, the current administration has suggested that some auction proceeds from the FCC could be diverted to help offset costs.
“The voluntary mitigations by wireless providers are sunsetting,” noted a senior FAA official. “This is no longer a temporary standoff; it is a fundamental shift in how we share the sky. Safety is non-negotiable, but the bill is significant.”
The Bottom Line: A Managed Evolution
By setting a multi-year horizon, the FAA is attempting to avoid the “cliff-edge” disruptions that nearly grounded thousands of flights in early 2022. For the aviation industry, the $4.5 billion cost is a bitter pill, but it represents the final price of admission for a future where 5G connectivity and flight safety must exist in the same thin slice of air.
US FAA Hq, The Wilbur Wright Federal Building Flickr Picture by Matthew G. Bisanz
