NBAA, NATA Urge Assistance for Radio Altimeter Mandates

NBAA and NATA are appealing to the U.S. Federal Communications Commission (FCC) to authorize reimbursements for any new equipment requirements for Part 91 and 135 operators that come in tandem with expanded use of the upper C-Band for wireless services.

The associations made that appeal in joint comments on an FCC proposal to auction up to 180 MHz of spectrum in the 3.98 to 4.2 GHz range (the upper C-band) for next-gen wireless services. That proposal has come at the direction of Congress that the FCC repurpose at least 100 MHz of the upper C-band. Planning for an auction in 2027, the FCC has solicited comment on the plans, marking a departure from its approach with the lower C-band expansion.

These plans would materially alter the adjacent-band radio frequency environment for aviators, the associations noted, explaining that aircraft radio altimeters are “safety-critical systems used during instrument approaches, low-visibility landings, offshore and mountain terrain operations, as well as helicopter missions conducted at low altitude and in complex environments. These systems are essential to the safe operations of thousands of aircraft in the National Airspace System.”

As a result, the FAA has issued a companion notice that would implement new interference-tolerant performance standards for radio altimeters that would safeguard such systems operating in the adjacent band. “The necessity and timing of this fleetwide upgrade are directly tied to the commission’s spectrum repurposing decision,” the associations pointed out. “Absent the commission’s action to authorize full-power operations in the adjacent band, these altimeter upgrades would not be required on the accelerated timeline now contemplated.”

Further, the associations added, the costs of replacing or modifying radio altimeters impose significant capital, certification, and operational burdens. The FCC has a longstanding emerging technologies framework that entitles entities compelled to modify equipment due to commission-initiated spectrum-use changes to reimbursement.