Delta Air Lines' Boeing 737-900ER is its most active aircraft type

Delta Air Lines operates with a diverse fleet that includes eight types of aircraft in its mainline operations. Among these, the Boeing 737-900ER stands out as the most active aircraft type within Delta's fleet. According to data from Cirium, Delta conducted 19,028 flights using the 737-900ERs in April, making it the airline's busiest single aircraft type. Delta has a total of 163 Boeing 737-900ERs, positioning it as the largest operator of this aircraft globally.

The Boeing 737-900ER was redesigned from the less popular 737-900 and received orders from Delta starting in 2011. Post-pandemic, Delta bolstered its fleet with the purchase of 33 additional units from LionAir and Batik Air. Delta plans to retrofit these with interiors that match their existing 739 subfleet.

Meanwhile, Delta's second-largest fleet, the Airbus A321-200, accounted for 14,238 flights in April. The carrier operates 127 units of this model. "The A321s are mainly intended as high-capacity replacements for MD-88s," the company stated while highlighting its lower Maximum Take-Off Weight (MTOW) and short-range service designed for high-capacity transit.