US Airways’ international expansion strategy to points south focuses on limited access markets, places where a bilateral treaty restricts air service to/from the U.S. Places like Brazil.

And Colombia. The U.S.-Colombia treaty sharply restricts flights between the two countries. When extra frequencies became available in 2008, there was a feeding frenzy. Spirit, jetBlue, Continental, Delta, American, and US Airways were all involved, seeking a total of 77 flights per week. And while the bilateral had been liberalized, the U.S. Department of Transportation only had 28 flights per week to hand out.

Spirit, Continental, jetBlue, and Delta were the winners. Each was awarded seven weekly frequencies, so enough for a daily flight. The awards were to serve a specific market (city pair). All the winning bids offered flights to Bogota. The U.S. cities gaining service were Ft. Lauderdale (Spirit), Orlando (jetBlue), Houston (Continental), and New York City (Delta). US Airways’ proposed Charlotte-Bogota service was rejected.

Now fast forward a year. Delta’s JFK-Bogota flight has proven to be a big money suck. The airline is now asking the DOT for permission to shift those seven frequencies to Atlanta, so as to provide two flights a day from there to Bogota (Delta had a preexisting daily ATL-Bogota flight).

Put bluntly, Delta would not have been awarded frequencies for a second ATL-Bogota flight had that been what they requested last year. And they didn’t even bother to try. Be real interesting to see whether one or more of US Airways, American, jetBlue, or Spirit objects to Delta’s request, and if so, what the DOT does about it.

CLT-Bogota is far from a given should US Airways still consider the route viable and objects, but it has a fighting chance.