Air travel starting in Germany is billed in Euros. While most Oneworld airlines charge creditcards of european passengers at a transaction location within Europe, only American Airlines is using Fort Worth (TX) as transaction location even for Euro billed charges. For this reason, all credit card payments to American Airlines in Europe are subject to the usual foreign transaction fee (even for cards denominated in euros). All other Oneworld airlines are using european transaction locations for Euro billed flights.