United Airlines was one of the major operators of the Boeing 727, a narrow-body, tri-jet airliner that played a crucial role in the airline's domestic and short-haul international routes from the 1960s to the 1990s. The Boeing 727 was known for its ability to operate on shorter runways and at smaller airports, making it ideal for regional travel. United's fleet of 727s helped the airline expand its network and offer more frequent flights during the rise of commercial aviation. Though retired from service in the early 2000s, the 727 was a workhorse for United Airlines for several decades.