FAA Proposes Flight-Manual Limits for Helicopters Over 5G Radio-Altimeter Interference in Canada

The FAA has proposed an airworthiness directive, published Oct. 8, that would impose flight-manual restrictions on helicopters equipped with radio altimeters potentially vulnerable to 5G interference when operating in Canadian airspace. The proposal covers helicopters with radio altimeters from 20 listed manufacturers, including Airbus, Bell, Leonardo, MD Helicopters, Robinson and Sikorsky.

The agency said interference from wireless broadband signals could cause altimeter anomalies that go undetected by pilots or aircraft systems, particularly near the ground. Operators of helicopters that have not demonstrated radio-altimeter interference tolerance would have to revise their rotorcraft flight manuals before flying in Canadian airspace. The restrictions would prohibit certain offshore approaches that rely on radio-altimeter minimums, as well as hover and search-and-rescue autopilot modes that depend on radio-altimeter data.

Transport Canada notified the FAA in March that changes to Canada's 5G interference protections, taking effect July 1, 2026, would leave helicopter radio altimeters exposed to a more severe interference environment. Helicopters modified to demonstrate the required interference tolerance would not be subject to the proposed operating limitations.

The FAA estimates that about 5,500 U.S.-registered helicopters have radio altimeters, with 1,128 potentially equipped for the affected operations. Revising the flight manual would cost an estimated $85 per aircraft, and helicopters that do not operate in Canada would incur no costs under the proposal. The FAA is accepting comments through Nov. 23, 2026.

The proposal shows how a spectrum decision made by one country's regulator can reach into another country's airworthiness rules. The Canadian change is what triggers the restriction, and it lands on aircraft types that depend on radio-altimeter data for low-altitude work: hover, offshore approaches and search-and-rescue autopilot modes.

For helicopter segments built around those tasks, the practical divide is between aircraft that have demonstrated interference tolerance and aircraft that have not. The cost the FAA cites is small for the manual revision itself, so the larger question for an operator is whether the restricted modes are ones its Canadian missions actually use.

The next dated milestone is the close of the comment period on Nov. 23, 2026, which is when operators and manufacturers can put their positions on the record. The Canadian rule change takes effect July 1, 2026, the date the exposure described by Transport Canada begins.