Approximately 80 percent of domestic aircraft have already undergone the necessary upgrades, although some major carriers still have a portion of their fleet awaiting retrofitting. For example, Delta Air Lines has 190 planes remaining to be updated, while JetBlue has 17. Supply chain issues have been identified as a contributing factor to the delays, according to the Airlines for America trade association. However, United, Southwest, and American Airlines have confirmed that they will have all their planes compliant by the deadline. Additionally, 65 percent of aircraft flying from international destinations to the US already have up-to-date altimeters, allowing airlines to utilize these planes whenever feasible.
