Allegiant Air’s ambitious plan to fast-track the retirement of its MD-80 fleet remains on track, and the associated efficiency gains along with expanded use of revenue management tools has executives bullish on the company’s revenue-generation potential. Las Vegas-based Allegiant ended the first quarter with 32 MD-80s in its 88-aircraft fleet. It plans to park five this quarter, eight in the third quarter, and the last 19 in the final quarter. It will add 26 Airbus ...