I am traveling Spring 2014 from the US to Spain. I wanted to use my American Airlines frequent flier (AAdvantage) miles to best advantage, so to speak. I learned that it is possible to incorporate free domestic layovers into my journey. As I have family in Dallas, that intrigued me.
showed available flights from San Francisco (SFO) to Madrid (MAD) that connect through Los Angeles, Dallas, Chicago, New York or Miami. AAdvantage rules require that the layover stops must be on published routings from the origin to destination. In my case, I am flying out of San Francisco and going to Madrid. So I could easily arrange my stop on published routes through Dallas (DFW), an AA hub airport.
Moreover, I discovered that it is possible to make additional layovers at cities in the US wherever the flights stop or change planes. That means that, when booking with AA miles, one can hopscotch across the country, choosing several stops along the way if one chooses.
You may create these layovers on either departure or return, or on both the outbound and return flights. This is only the case when you use miles to pay for the flights. In other words, purchased tickets do not allow this flexibility. Organizing free domestic layovers is a big bonus to using AAdvantage miles.
Note that AAdvantage does not allow free layovers at a location outside the U.S. (e.g. London). That is just as well, as I was not keen on dealing with the Airport Departure Tax (APD) for a London layover on this trip.
If you book a flight using miles, regardless of whether you make any layover stops, be sure to check whether any of the flight legs are operated by a Europe-based partner carrier such as British Airways or Iberia. In some cases, if the flights are operated by partners, you may have to pay $200 or more in airline fees for those legs.
I booked my trip US to Spain and back with a stop in Dallas for several days. Total airline fees for my round trip are less than $62. ¡ El mas barato es mejor !