US Airways added flights between CLT and the Mexican resorts of Cabo (five days a week, all but Wednesday and Friday) and Puerto Vallarta (four days a week, no Monday, Tuesday, or Thursday) earlier this month. What’s that all about, you ask?

US Airways now serves 23 destinations in Mexico, Central America, and the Caribbean from Charlotte. All but two — Mexico City and San Jose, Costa Rica — have beaches nearby. So clearly adding Cabo and Puerto Vallarta doesn’t change the general formula.

It does though highlight the limits of the airline’s expansion to points south. The last time US Airways successfully added a destination in Mexico, Central America, or the Caribbean from CLT was over five years ago. That was Bridgetown, Barbados, and it’s a weekend-only destination. When an extra plane became available because of delays in the US Airways/Delta slot swap, the airline determined the best possible use were flights to resorts on Mexico’s Pacific coast. Sure, US Airways has three or four flights a day to both Cabo and Puerto Vallarta from its Phoenix hub, but people in the eastern U.S. tend to go to resorts on the Atlantic, not the Pacific.

Now let’s suppose both these new routes work out and the airline were thinking of adding more flights from CLT to cities in Mexico it already flies to from Phoenix. The only other Mexican cities that get even two flights during a day at least a portion of the year not served from CLT are Guadalajara and Mazatlan. Mazatlan is on the coast, so weekend (seasonal?) service from CLT might be a possibility.

Guadalajara, however, is inland. It’s more of a business center, exactly the sort of market US Airways has typically avoided serving from CLT in the past. Time will tell if the airline changes its business model and tries to make non-beach markets like it work. If not, there’s extremely limited growth potential for US Airways from CLT to points south.