Since its U.S. Airways tie-up that in 2013 created the world's biggest carrier, American has been both the least lucrative of the four majors, and accumulated the most debt. And the combination limits its ability to reduce the big pile of borrowings.

In 2026, the airlines with the highest debt loads are generally the major U.S. "Big Three" (American, United, and Delta) and certain European groups like Air France-KLM. American Airlines historically carries the highest total debt in the industry, often hovering between $30 billion and $40 billion, largely due to its massive fleet renewal programs and historical merger costs. While the airline has been aggressively "deleveraging" (paying down debt) using record profits from the 2024-2025 travel boom, it remains the most leveraged carrier. In Europe, Air France-KLM still carries significant debt originating from state-backed loans during the pandemic era. It is important to distinguish between "bad debt" and "productive debt"; many of these carriers use debt to finance new, fuel-efficient aircraft like the Boeing 787 or Airbus A321neo, which lower operating costs over time. By 2026, while industry-wide net profits have hit record highs of $41 billion, the interest payments on these multi-billion dollar balances remain a significant line item on the balance sheets of the world's largest legacy carriers.