Federal Aviation Administration officials are interested in programmes under which the cellular industry helps foot the multi-billion-dollar expense of modifying tens of thousands of radio altimeters to withstand interference.
That is according to newly released FAA memos summarising two recent meetings between FAA officials – including administrator Bryan Bedford – and representatives from the aerospace and wireless industries.
The meetings come as the FAA prepares to finalise a rule requiring aircraft operators upgrade all radio altimeters to prevent interference from cellular signals in the 3.98-4.2GHz bandwidth, which wireless providers plan to begin using after 4 July 2027.
The FAA says those transmissions can interfere with altimeters, which use the 4.2-4.4GHz bandwidth.
The FAA’s 5 January proposal would require all altimeters – some 58,000 on 40,000 aircraft – be upgraded, costing $4.5 billion. Airlines would need to comply first – by a date sometime between 2029 and 2032 – followed two years later by other operators, the FAA has said.
On 9 January, representatives from cellular firms AT&T, T-Mobile and Verizon, and from cellular trade group CTIA, met in Washington to discuss the issue with FAA officials, including staff from the agency’s Office of Chief Counsel and its Office of Senior Technical Experts.
They discussed “potential incentive payments by the wireless industry for aviation retrofits, as well as an update from the wireless industry on emissions data that was recently provided to the aviation industry”, the FAA says of the meeting.
“With respect to incentive payments, the FAA requested that the wireless industry comment on the feasibility of voluntary agreements, in lieu of FAA regulation, to accomplish equipage with next-generation radio altimeters.”
Wireless industry trade group CTIA does not respond to a request for comment.
The subsidy payment idea is not new.
Last year, the Federal Communications Commission, in allocating the 3.98-4.2GHz bandwidth to wireless providers, requested comment about “proposals and mechanisms to facilitate” altimeter retrofits, with options including payments to airlines, operators and manufacturers.
Separately, on 16 January representatives from Honeywell discussed the altimeter issue during a meeting in Washington with FAA staff including administrator Bryan Bedford and FAA deputy associate administrator for aviation safety.
During that discussion, the Honeywell team “shared preliminary estimates for cost and schedule for next-generation radio altimeter system compliance”, an FAA memo says.
The FAA is considering hosting a broader meeting in which “all the relevant stakeholders” will be invited to participate, according to one of the documents.
