An original interactive 747-400 cutaway connects ten aircraft parts to explanations of their functions, from the raised cockpit to the tail APU.
The hump, wings and tail hide a network of working spaces and systems. This cutaway connects those spaces to the equipment that keeps a 747 flying, with short explanations and links to the full guides.
Explore the aircraft
A simplified passenger 747-400. Select a numbered part or a label to discover what it does.
1Flight deck
On the 747-400, two pilots use electronic flight displays and crew alerts to monitor the aircraft. Earlier classic 747s also had a flight engineer. The raised cockpit leaves the main-deck nose available for a cargo door on factory-built freighters.
2Fuel tanks
Integral tanks occupy the wing structure, with a centre wing tank between the wings. Pumps and crossfeed valves connect the tanks to the four engines. Tail tanks and auxiliary body tanks depend on the variant and installed options.
3Cargo holds
A passenger 747 carries baggage and freight in lower holds ahead of and behind the wing centre section. Factory-built freighters add main-deck cargo space and an opening nose. Their pallets and containers are held in place by the loading and restraint system.
4Landing gear
There are two nose wheels and four main gear units with four wheels each: two wing gear and two body gear. Spreading the load across these units helps manage pavement loading. The body gear also steers during tight ground turns.
5Engines
The four wing-mounted engines propel the aircraft. They also drive generators and hydraulic pumps, while compressor bleed air supports pneumatic systems. Engine models changed across the 747 family, from the early JT9D to the 747-8’s GEnx-2B.
6Hydraulics
Four hydraulic systems supply actuators for flight controls, landing gear and other equipment. Each system has its own fluid circuit and pumping sources. The purple paths here show the idea of distributing hydraulic power, rather than the actual pipe routing.
7Electrical power
Engine-driven generators power the electrical system in flight. At the gate, the aircraft can use external power or APU generators. Distribution buses and protective devices connect these sources to lighting, avionics and other equipment.
8Tail APU
The auxiliary power unit is a separate gas turbine in the tail cone. It can provide electrical power and compressed air on the ground when the main engines are off. That air supports cabin conditioning and main-engine starting.
9Cabin air
Air-conditioning packs cool and condition compressor bleed air before it reaches the cabin. Outflow valves regulate how quickly air leaves, controlling cabin pressure. The drawing opens the fuselage for explanation; the real cabin is an enclosed pressure vessel.
10Flight controls
Ailerons help control roll, elevators control pitch, and the rudder controls yaw. Spoilers help manage lift and roll. Leading-edge devices and trailing-edge flaps reshape the wing for low-speed flight; their position is separate from the main fuel tanks inside it.
The upper deck starts with the flight deck and extends into a passenger cabin on a passenger 747-400. The main deck carries most passengers. Below it, the lower holds carry baggage and freight, separated by the wing centre section.
A factory-built freighter uses its main deck for cargo and has a shorter upper deck. Its raised cockpit leaves the nose free to open for loading. The passenger aircraft in this drawing has a fixed nose.
An engine produces thrust, but also supplies power to other systems. Fuel reaches it through pumps and valves; hydraulic pumps and electrical generators driven by the engine support the rest of the aircraft. Compressor bleed air feeds the pneumatic system.
The hydraulic and electrical guides explain how several sources and distribution paths provide redundancy. The lines in the cutaway illustrate these connections and do not reproduce actual installation routes.
Facts on this page are checked against the primary and institutional references below.
Almost everything inside a 747-400 cabin was buyer-furnished and fitted under STC, which is why approved cabin modifications run to dozens.
Four 747-400s rebuilt with a swollen fuselage and a swing tail to carry Boeing 787 wings and fuselage barrels between factories.
Announced in 1985, the 747-400 added winglets, a two-crew glass cockpit and a new interior, becoming the best-selling 747 generation.
A complete Boeing 747-400ER guide: specifications, range, fuel tanks, engineering changes, Qantas's six-aircraft fleet, service history and FAQs.
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