United Airlines is preparing to retire its entire fleet of Boeing 767-300ER aircraft by December 2027, marking the end of more than three decades of service for the type. The airline has operated 37 of these aircraft, which have been central to its transatlantic and transpacific routes since the first one arrived in April 1991.
The Boeing 767-300ER was once a key part of United’s widebody operations, providing flexibility in range and payload while replacing older trijets and early-generation twins. At its peak, the aircraft accounted for about one-fifth of United's widebody capacity. However, with an average age of over 27 years for the -300ERs and more than 22 years for the -400ERs, maintenance requirements have increased as passenger expectations and industry standards have evolved.
"Fuel remains the single largest operating expense for airlines, often accounting for 25–30% of total costs. The Pratt & Whitney W4000 engines on United’s 767s were state-of-the-art in the early 1990s, but today’s high-bypass turbofans deliver up to 20% better specific fuel consumption," the article states.