United Airlines is among the largest global airlines, operating with a fleet of 1,015 aircraft. The airline's aircraft include both narrowbody and widebody planes, with the average fleet age standing at 15.9 years. The widebody segment consists of 225 Boeing-manufactured jets, specifically 96 Boeing 777 aircraft. This fleet comprises 19 Boeing 777-200s, 55 777-200ERs, and 22 777-300ERs. The Boeing 777-200s and 777-200ERs have a combined older lineage, averaging 25.8 years.
United Airlines distinguishes between its legacy 777-200ERs and those acquired from Continental Airlines following their merger. The differentiation lies in the engines powering these aircraft. According to data from ch-aviation, United Airlines operates 33 legacy 777-200ERs and 22 from Continental. The legacy versions are equipped with Pratt & Whitney PW4000 engines, while the ex-Continental versions run on GE Aerospace GE90 engines. Each of the PW4000 engines can generate up to 97,300 lbf at takeoff.
As per Pratt & Whitney, the PW4000 112-inch engine represents "the reliability, experience and Extended-range Twin-engine Operations (ETOPS) leader for the 777 aircraft, providing the best customer value." It boasts service-proven technologies such as single-crystal super alloy materials, contributing to its operational performance and durability.