The U.S. Court of Appeals for the Eleventh Circuit, on August 20, 2026, issued an opinion in Delta Air Lines, Inc. and Aerovias de Mexico, S.A. de C.V. v. U.S. Department of Transportation vacating a September 2025 order issued by the U.S. Department of Transportation1 (DOT Order) that revoked the antitrust immunity (ATI) held by Delta Air Lines and Aeromexico.
In reaching its decision, the court reiterated that the standard of review of agency decisions of this type tends to be deferential, with courts reversing agency decisions only if they are "arbitrary and capricious" or otherwise unsupported by fact or law.2 In striking down the DOT Order, the court determined that DOT's action was "arbitrary and capricious" in part because 1) DOT focused almost exclusively on competitive conditions for flights operating between the U.S. and Mexico City's Benito Juárez International Airport (MEX) and failed to analyze the broader impact of the Delta-Aeromexico joint venture on all U.S.-Mexico
