US Appeals Court Reinstates Delta-Aeromexico Joint Venture after DOT Block

On August 20, 2026, the US Court of Appeals issued a decisive ruling overturning the Department of Transportation's (DOT) 2025 order that effectively dismantled the joint venture between Delta Air Lines and Aeromexico. The court determined that the DOT's action was arbitrary and capricious, reinstating the cooperative travel program between the two carriers. This decision marks a significant win for Delta and Aeromexico, who had challenged the government's attempt to sever their decade-old alliance. The partnership, crucial to cross-border travel between the United States and Mexico, had been under threat after the Trump administration raised competition concerns related to the collaboration.

The Delta-Aeromexico joint venture, originally approved and granted antitrust immunity by the DOT in 2016, allows the airlines to coordinate schedules, pricing, and revenue sharing on routes connecting the US and Mexico. This legal protection facilitates integrated operations as if the two carriers were a single airline for transborder flights. The DOT's 2025 block was justified on grounds that Mexico had allegedly violated bilateral Open Skies agreements by restricting cargo flights to Mexico City’s Benito Juárez International Airport (MEX). This moratorium on cargo operations, following a rerouting mandate to Angeles International Airport (NLU), was deemed anti-competitive by US regulators and used to justify dismantling the joint venture.

However, the 11th Circuit Court of Appeals challenged the DOT’s rationale, highlighting inconsistencies in how the agency applied its competition analysis. Historically, the DOT evaluates airline alliances by scrutinizing the full country-to-country market, but in this case, it focused narrowly on operations centered around MEX airport. The appeals court found this approach flawed, noting the DOT failed to justify the significantly more restrictive market analysis compared to other similar alliances, such as United Airlines’ partnership with All Nippon Airways (ANA) in Japan.

The DOT had claimed that Delta and Aeromexico controlled 60% of the market share at MEX, suggesting a monopoly fostering collusion. Yet flights through MEX only represent 21% of total US-Mexico air traffic, meaning the agency disregarded 79% of relevant market data. The court criticized this selective use of statistics, confirming that the DOT’s case rested on cherry-picked numbers that distorted the competitive landscape. Legal experts point to this as evidence that the DOT's decision was politically motivated rather than based on sound economic reasoning.

Further undermining the DOT’s position was the agency’s simultaneous public criticism of former President Joe Biden and former Transportation Secretary Pete Buttigieg for their management of the bilateral agreement. The court noted that this inflammatory rhetoric did not substitute for a rational, data-driven justification for blocking the alliance. This political context, coupled with the inconsistent treatment compared to the United-ANA joint venture, strengthened the court’s finding that the DOT acted without proper cause.

The comparison with the United-ANA partnership was particularly telling. Tokyo’s Haneda Airport (HND), like Mexico City’s MEX, suffers from strict slot controls and operational restrictions, yet the DOT approved that alliance without issue. The appeals court found the DOT had not adequately explained why similar airport limitations produced vastly different regulatory outcomes. This lack of logical consistency was a central basis for overturning the block on the Delta-Aeromexico joint venture.

The reinstatement of the alliance is significant for the US-Mexico air travel ecosystem. Since its inception, the joint venture has served over 50 million passengers, operating approximately 30,000 cross-border flights annually across more than 20 routes. It generates roughly $3.5 billion in yearly revenue, underscoring its economic importance. Airlines, airport operators, and travelers stand to benefit from the restored stability and coordination that the partnership enables.

This ruling allows Delta and Aeromexico to resume coordinated scheduling, pricing, and revenue-sharing arrangements without interference. It brings certainty back to cross-border aviation markets, which are vital corridors for commerce and tourism between the two nations. The court’s decision also sets a precedent limiting politically-driven regulatory actions that fail to apply objective competitive analyses consistent with past practice.

With the joint venture restored, Delta and Aeromexico can focus on sustaining and potentially expanding their collaboration. This should improve connectivity and service quality on key routes connecting major US hubs with Mexico City and other Mexican airports. The decision highlights the critical role of judicial oversight in ensuring fair and balanced enforcement of aviation competition policies.