I have a question regarding Southwest Airlines’ flights between Dallas Love (KDAL) and Houston (KHOU). I have noticed that these flights are typically flying at 30,000 to 33,000 feet. Based on the details of the flights it appears that they are at cruise altitude for only 5-6 minutes.
Question: Why would they climb to such an altitude with such a short cruise time? Is this just pure economics of fuel savings, or does the airspace between and Dallas and Houston require such an altitude?