page_title: Boeing 777
section_title: Airframe and systems
hierarchical_section_title: Boeing 777 / Design / Airframe and systems
caption_attribution_description: English: Planform view of a Boeing 777-300ER, composite photo
context_page_description: The Boeing 777 is a wide-body airliner developed and manufactured by Boeing Commercial Airplanes, commonly referred to as the Triple Seven.
  The 777 was designed to bridge the gap between Boeing's 767 and 747, and to replace older DC-10s or L-1011s.
  Developed in consultation with eight major airlines, with a first meeting in January 1990, the program was launched on October 14, 1990 with a first order from United Airlines. The prototype was rolled out on April 9, 1994, and first flew on June 12, 1994. The 777 first entered commercial service with United Airlines on June 7, 1995. Longer range variants were launched on February 29, 2000 and were first delivered on April 29, 2004.
  It is the largest twinjet and has a typical 3-class capacity of 301 to 368 passengers, with a range of 5,240 to 8,555 nautical miles.
  It is recognizable for its large-diameter turbofan engines, six wheels on each main landing gear, fully circular fuselage cross-section, and a blade-shaped tail cone. It has fly-by-wire controls, a first for Boeing.
context_section_description: The wings on the 777 feature a supercritical airfoil design that is swept back at 31.6 degrees and optimized for cruising at Mach 0.83 (revised after flight tests up to Mach 0.84). The wings are designed with increased thickness and a longer span than previous airliners, resulting in greater payload and range, improved takeoff performance, and a higher cruising altitude. The wings also serve as fuel storage, with longer-range models able to carry up to 47,890 US gallons (181,300 L) of fuel. This capacity allows the 777-200LR to operate ultra-long-distance, trans-polar routes such as Toronto to Hong Kong. In 2013, a new wing made of composite materials was introduced for the upgraded 777X, with a wider span and design features based on the 787's wings.
  Unlike smaller airliners like the Boeing 737, no current 777 wings have winglets; instead, the exceptionally long raked wings of the 777 serve the same drag-reducing function. Large folding wingtips, 21 feet (6.40 m) long, were offered when the 777 was first launched, to appeal to airlines who might use gates made to accommodate smaller aircraft, but no airline purchased this option. Folding wingtips reemerged as a design feature at the announcement of the upgraded 777X in 2013. Smaller folding wingtips of 11 feet (3.35 m) in length will allow 777X models to use the same airport gates and taxiways as earlier 777s. These smaller folding wingtips are less complex than those proposed for earlier 777s, and internally only affect the wiring needed for wingtip lights.
  The airframe incorporates the use of composite materials, which comprise nine percent of its original structural weight (all models outside the 777-8 and 777-9). Elements made from composite material include the cabin floor and rudder. The main fuselage cross-section is circular and tapers rearward into a blade-shaped tail cone with a port-facing auxiliary power unit. The aircraft also features the largest landing gear and the biggest tires ever used in a commercial jetliner. The six-wheel bogies are designed to spread the load of the aircraft over a wide area without requiring an additional centerline gear. This helps reduce weight and simplifies the aircraft's braking and hydraulic systems. Each tire of a 777-300ER six-wheel main landing gear can carry a load of 59,490 lb (26,980 kg), which is heavier than other wide-bodies such as the 747-400. The aircraft has triple redundant hydraulic systems with only one system required for landing. A ram air turbine—a small retractable device which can provide emergency power—is also fitted in the wing root fairing.
caption: The planform view of a Boeing 777-300ER, with raked wingtips
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