The American airline stated that landing/takeoff requests at Humberto Delgado Airport have been "repeatedly" rejected since 2023. In a document submitted to the US Department of Transportation, the airline stated that Portugal should not be able to benefit from the unrestricted flight policy if it cannot guarantee similar access to American carriers.

Finally, the American airline notes that of all European airports, Lisbon has the third-lowest rate of American carriers (33%), a figure below the European average (45%).

The saturation of Humberto Delgado Airport leads to a high number of slot requests being rejected every year.