Delta Air Lines CEO Ed Bastian warned this month that US airlines must improve or "face being eliminated" as a jet fuel crisis sparked by the Middle East conflict puts the industry under fresh strain. Fuel prices have doubled since the war began, forcing carriers to cut flights and raise fares. Delta is reducing passenger capacity by 3.5% between April and June.

Spirit Airlines, the ultra-low-cost carrier that has filed for bankruptcy twice in two years, reported losses of $2.7bn last year with a negative operating margin of 22%. President Trump said his administration is considering buying Spirit. While budget carriers struggle, Delta posted an operating profit of $5.8bn with a 9.2% margin, while United earned $4.7bn at 8%.

The four leading airlines — Delta, United, American and Southwest — now control 80% of domestic seat share. United CEO Scott Kirby confirmed he's pursuing a merger with American Airlines, though the proposal has faced significant pushback. The fuel crisis is accelerating consolidation, with network carriers poised to cement their dominance when the industry stabilises.