Major airline industry players in the US warned it was critical to extend operator 5G C-Band mitigations in place to avoid possible interference with cockpit safety systems until the end of 2023, due to delays in fitting new equipment.

In a letter to US authorities, players including the Aerospace Industries Association, Helicopter International, Airbus, Boeing and Thales warned radio altimeter manufacturers and airlines would likely be unable to meet deadlines to retrofit kit in small regional aircraft of December or mid-2023 for larger craft.

An inability to meet targets set by the Federal Aviation Authority (FAA) earlier this year was blamed on global supply chain issues; certification problems for one piece of equipment; and claims the FAA only recently issued stable criteria for altimeters.

AT&T and Verizon voluntarily agreed to 5G C-Band policies designed to mitigate any risk of interference with airline equipment, including maintaining low power levels close to airports and tilting antennas down. These measures are currently due to expire at end-July 2023.

Referring to the last-minute nature of previous agreements on the issue, which delayed operator activation of 5G on the C-Band and led to flight cancellations, the group of aerospace companies called for immediate action to extend current measures.

They also want regulation put in place outlining reasonable mitigations to be taken around airports to avert future issues as other parties start to use the spectrum.

“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 group wrote.

“Aviation stakeholders call on the administration to meet with us to discuss a way forward that will achieve the goal of moving 5G forward, while ensuring passengers and cargo reach their destinations safely and on time,” it added.