The letter signed by Airlines for America, Boeing Airbus, Embraer, aviation unions and others backed the Federal Aviation Administration 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 saying 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."

(Reporting by David Shepardson)