The Boeing 747-400 is the latest, longest ranging, most advanced and best-selling model of the 747 family. It is the second largest commercial airliner after the Airbus A380. It was announced by Boeing Commercial Airplanes in October 1985, rolled out in January 1988 and first flew on April 29, 1988. Production of the 747-400 passenger version officially ended on March 15, 2007. The last to order the -400 was China Airlines in November 2002, with the last passenger 747-400 constructed in 2005 and delivered in April of that year. It was the 1358th aircraft produced. The 747-400 is set to be replaced by the Boeing 747-8 in 2009.

United Airlines (UA) is one of the only two US airlines that still operate the 416-passenger 747-400. On December 9, 2004, UA made history when Flight 869, a 747-400, landed at Ho Chi Minh City, Vietnam. The scheduled flight from San Francisco via Hong Kong was the first by a US airline since the end of the Vietnam War, when Pan Am halted service shortly before the fall of Saigon.

United offers in-flight entertainment on all its mainline aircraft. UnitedFirst Suite is offered on the 747-400, which features a 78-inch pitch flat-bed seat that reclines to 180 degrees. On board, passengers can enjoy pre-takeoff beverages, a five course meal, and a personal entertainment unit featuring nine channels of video as well as an additional fourteen feature film titles. Passengers also have access to personal phones and laptop power ports, as well as comfortable pillows and duvets.

UnitedEconomy International is also available on the 747-400. Seats range from 17 to 18 inches wide, and have 31 inches of pitch. The in-flight entertainment system features nine channels of entertainment, along with audio channels. Shortly after takeoff, passengers are served a beverage with cocktail snacks. The main meal consists of a salad, an appetizer, a choice of hot entrées and dessert. On longer flights, United also offers a light pre-arrival meal.