Airlines will struggle to retrofit regional and cargo aircraft to avoid interference from wireless 5G C-Band by the prescribed deadlines, the aviation industry is warning US government officials.

Concerns that 5G services could interfere with aircraft altimeter avionics have already caused disruption at some US airports.

A letter signed by Airlines for America, Boeing, Airbus, Embraer, aviation unions and others are backing the Federal Aviation Administration (FAA) request to mandate an extension of mitigation by wireless carriers as airlines retrofit radio altimeters.

“It is critical to extend these mitigations through the end of 2023 to allow airlines time to complete the retrofit,” the letter said. Because of global supply chain issues “air carriers will likely be unable to fully meet either the December 2022 deadlines for smaller regional aircraft and many large transports nor the July 2023 retrofit deadline,” it added.

“Our aviation coalition strongly believes that instead of once again waiting until the eleventh hour, now is the time for the leadership at federal agencies and the White House to implement a solution that allows 5G to move forward and avoid further flight delays and cancellations,” the letter said.

The aviation industry letter said that since January “the FAA has documented over 100 FAA incidents of potential 5G interference … Unfortunately, the US government agencies do not appear to be on the same page with respect to these safety issues.”

In its letter to the White House, the aviation industry warns that “inter-agency government progress appears to be at a stalemate, while stakeholders are doing their part to address these issue.”