Boeing 747 8 Assembly
The Boeing 747 8, which comes in a passenger version, the Boeing 747-8 Intercontinental (8i) and freight version the Boeing 747-8 Freighter (8f), is assembled in Boeings’ own factory at Paine Field, Everett north of Seattle in Washington State.
The Boeing building is said to be the largest building by volume in the world, little wonder when you consider the size of the aircraft that are built within. To get some perspective of size, the whole of the Disneyland amusement park in Anaheim, California could fit inside with room left over for a car park. There have even been occasions when clouds have formed under the eleven story high ceiling.
The Boeing Factory
In construction of the Boeing 747 8, nothing is actually manufactured in the Boeing plant, it is simply an assembly location. Parts for the Boeing 747 8 are made all over the world, such as seats from Germany, wing elements from China and flaps from Australia. It takes around 6 million parts to create one aircraft, but very little of those are stored in the plant. Boeing uses a “Just in Time” system which means that parts arrive at the factory just prior to being required for the particular phase of construction. This is closely monitored by computer inventory systems which flag if a part that is critical to the next phase has not yet arrived. It sometimes happens that a part does not arrive on time but it is rare. For example, the General Electric engines that are valued at $20 million each don’t arrive until a day or two before the completed plane is due to roll out of the factory.
747 8 Assembly Process
The assembly process begins with the wing, the most critical part of the aircraft. A quarter of the factory floor space is given over to the construction of the wings. The wing starts by being stood on its edge so that workers can start affixing the ribs and skin to the main spar. In the factory you will not see one robot. Each aircraft is built by hand, so each of the fasteners is attached by a worker to a very strict tolerance and then the work is rechecked.
The fuselage is assembled in three main pieces, the nose section, the centre section which includes the wing box and the after section. The nose section is created in one piece whilst the middle and after sections are assembled upside down to start with. They are then turned through 180 degrees on a reel type device which allows the workers easy access to all parts with the final part being the roof construction.
The most critical part of the whole operation is the marrying of the three fuselage pieces together. This operation is usually performed in the wee small hours of the morning when the fewest amount of workers are on the factory floor. It is a very exacting process and requires a high amount of coordination and concentration.
Once the aircraft pieces are married together, a very through inspection is carried out to check no parts have been left behind. Mirrors and flashlights are used to look into every nook, cranny and cavity, searching out even the smallest nut or bolt. Any of these that ended up falling in the wrong place could spell disaster through power short outs or similar.
Once the the aircraft is put together, heavy concrete blocks are hung from each of the engine pylons to simulate engine weight. Without these, the aircraft would sit back on its tail. The aircraft is now ready to leave the factory, the on-board flight system and electrics have been tested and now the engines need to be mounted. Each $20 million engine weights in at around 7 tonnes and is attached by eight bolts. The tolerance for the fastening of these bolts is extremely critical. The forward bolts are designed to sheer off before the rearmost, so in the event of an engine coming off, it will drop by the front first and away from the wing as opposed to going up and over and more than likely through the wing. Comforting thought.
The aircraft is now wheeled out of the factory and off to the paint shop. Here they first remove the layer of green vinyl material which has been in place through out the construction to protect the skin in the factory. The bright and shiny metal is revealed and now painting the colours of the airline customer begins. The thickness of the paint coat is strictly controlled so that it isn’t so thick that metal corrosion can’t be detected as well as not adding too much weight to the aircraft and thereby increasing fuel burn. The weight of the paint is around 500kg which is the same weight as 5 to 6 passengers. It will be 4 years before a repaint will be required.
So far, sales of the Boeing 747 8 have been soft. The initial production rate was two aircraft per month. In April 2013 this was cut down to 1.75 per month with a further cut to 1.5 aircraft per month in October of that year. In June 2015 the production rate was cut down to 1 aircraft per month which is a year earlier than first planned. We see that Airbus is also struggling a bit with sales for the Airbus A380 Super Jumbo, so let’s see what the future is for these supersized aircraft.
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