For example, if you are Platinum of American Airlines you can become Gold on Delta. Or, if you are Premier Gold on United you can become Gold on Delta. According to the official rules a status match is a one-time thing and is good for 90 days, or all the way to January 31, 2018, if you meet the associated flight requirements.
Back in May United and Delta began offering low fares to Europe from American Airlines’ major hub, Dallas-Ft. Worth. Those fares disappeared, but now they have re-appeared. Austin and San Antonio are included. Many cities in Europe are available.
The air fare war for flights from the United States to Europe continues, with some routes on some dates still available. Low fares are available from several U.S. cities to several European cities on American, Delta and United Airlines.
American Airlines and British Air are offering flights from Chicago ORD to London LHR for $553 round-trip, from September 2016 all the way to May 2017. Christmas and New Year’s are excluded from this low fare.
Note that other airlines may match this fare, or even extend it earlier in the Fall 2016 and Spring 2017. Delta has been engaged in an airfare war with American, so American may well choose to do a match.