Delta Air Lines (NYSE: DAL) highlighted a disappointing performance in transatlantic markets this summer when company leaders spoke at Morgan Stanley’s Laguna Conference this past week. The airline primarily noted that July-August was no longer the peak season for high-end European leisure travel, with premium revenue peaks pushing as far back as October. Well over half of Delta’s revenues now come from non-main-cabin revenue streams (specifically premiums and ancillaries), and main cabin margins were flat to down.