The move seems an obvious effort to compete with low-cost transatlantic carriers such as Norwegian Air Shuttle, Iceland-based WOW air, and Level, a recently launched Spanish entrant in the cheap-flights-to-Europe race.
Closer to home, Delta Air Lines has also begun selling no-frills basic economy fares across the Atlantic.
Those tickets are guaranteed to be the airlines' lowest available at the time of booking, just like domestic basic economy fares, which all three of the biggest U.S. carriers (the other one is United Airlines) rolled out last year. As Frommer's reported in January, many foreign-flagged carriers have introduced similar ultra-restrictive Hand-Baggage Only (HBO) fares.
Also just like domestic basic economy fares, the long-haul international versions from Delta and American come with numerous restrictions: Basic economy passengers have to board the plane last, they can't get a seat assignment ahead of time unless they pay more, they're not eligible for upgrades of any kind, and they have to pay a fee for their first checked bag, which is a policy that is not usually in place on flights from the U.S. to Europe.
American hasn't announced yet what the checked bag fee will be for transatlantic basic economy passengers. Delta's is currently $60.
Obviously, customers considering these tickets will have to think about whether they can cram everything they need for a European vacation into a carry-on.
But at least you can bring a carry-on.
American's domestic basic economy fare allows passengers only one personal item that can fit under the seat in front of them (overhead bin usage comes with yet another fee). But the transatlantic version allows one carry-on, too. Delta allows basic economy passengers to use overhead bins on both types of flights for free.
As for making ticket changes or selecting seat assignments in advance, basic economy flyers will be charged extra for those services as well.