Skip to Main Content Why Delta and United Can Fly Above the Turbulence in Air Travel - Barron's This copy is for your personal, non-commercial use only. Distribution and use of this material are governed by our Subscriber Agreement and by copyright law. For non-personal use or to order multiple copies, please contact Dow Jones Reprints at 1-800-843-0008 or visit www.djreprints.com. Delta Air Lines bought an oil refinery outside of Philadelphia in 2012. (SAUL LOEB / AFP via Getty Images) I'm not a technical ...