Southwest Airlines this week began service out of Houston's Bush Intercontinental Airport for the first time since 2005, with 15 daily departures to five markets: Dallas, Chicago, Nashville, New Orleans and Denver. The first flight to the airport on Monday morning was from Dallas, a callback to the first flight in the carrier's history on June 18, 1971, from Dallas to what was then Houston Intercontinental Airport. "Here we are, 50 years later, and we were able to bring the cocktail napkin back to its original routes," VP of Southwest Business David Harvey said, referring to the oft-told story of Southwest founder Herb Kelleher doodling his idea for the airline on a cocktail napkin, showing the connection of the Dallas, Houston and San Antonio triangle. Houston is only one of several new markets in Southwest's plans this year, however. Harvey spoke to BTN transportation editor Michael B. Baker about the network expansion and how it fits with the carrier's plans to expand its corporate business.