Airlines think they can accelerate 5G altimeter updates, but want compensation – FlightGlobal

US airlines say that with compensation they can move faster to make altimeters resistant to interferance.

Airlines now think they can update most of their radio altimeters to be “5G” compliant by 2029, quicker than they previously predicted — so long as certain conditions are met.

Those conditions include that airlines receive compensation for the cost of the multi-billion-dollar project, and that altimeter manufacturers and regulators support a fast pace of adoption.

Representatives for airlines and aerospace manufacturers made their new timeline and conditions known to US Federal Communications Commission (FCC) officials in recent weeks, including in letters and during meetings, according to recently released regulatory documents.

The aviation industry faces the need to retrofit or replace altimeters on all aircraft in the coming years to prevent interference when cellular companies start using a new sliver of radio bandwidth. The cell providers market the bandwidth as part of their 5G services.

In March, airline and aerospace associations told the Federal Aviation Administration they required until 2032 to update altimeters, citing the need to develop altimeter standards, ramp production and complete actual installations.

Now, the industry expects altimeters on most aircraft operated by Part 121 operators (meaning airlines) can be upgraded by end-2029. They expect they can complete the work on all other airliners by end-2030, according to a newly released 26 March letter to FCC secretary Marlene Dortch. The aircraft in the 2029 bucket have altimeters that can be retrofitted, while those in the 2030 bucket will require new altimeters.

“Accelerating the next-generation radio altimeter upgrade… is readily achievable with proper incentives and reimbursements,” says the letter.

It is signed by representatives from Airlines for America, Regional Airline Association, Aerospace Industries Association, Airbus, Boeing, Collins Aerospace, Embraer, Honeywell and Thales.

Meeting their revised timeline will require “compensation for the reasonable cost” of the updates, the letter says.
A4A declines to provide additional comment.

The industry’s ability to hit the revised timeline also depends on regulatory approvals (including for altimeter retrofits that can be completed overnight) and altimeter manufacturing capacity, it adds.

The industry changed its tune after reviewing “opportunities to invest in additional production facilities and upgrade capabilities”, says the letter.

The FCC plans in 2027 to finish auctioning to cellular companies rights to transmit in the 3.98-4.2GHz spectrum, called the “Upper C-Band”.

Problem is, those transmissions can interfere with radio altimeters, which operate in the nearby 4.2-4.4GHz range.
To head off a big problem, the FAA in January proposed requiring altimeters be retrofitted or replaced to be interference tolerant.

Its proposal calls for airlines to complete the work first, between 2029 and 2032. It would give other aircraft — charters, business and general aviation types — an extra two years.

The prospect of airlines receiving compensation for the updates is not unheard of. The FCC in a 2025 proposal requested comments about such a scheme.