Modern Airliners - Boeing 747 (2023)

The Boeing 747 was the Queen of Skies for near on 50 years and has now all but disappeared as the large, more economical twin jets take over. This demise was also hastened by the downturn intravelcaused by Covid 19.

Being the first wide-body aircraft ever built, the Boeing747 was the result of the demands of growing trans-continental(USA) and trans-oceanic travel markets in the 1960s.

The Boeing 747 on its main deck has two aisles where typically the economy cabin has a seat configuration of three seats on each window side and four seats in the centre, known as 3-4-3. The distinctive bubble atop the front of the fuselage accommodates the flight deck and in the first 747s during the 1960s, there would be a first-class lounge in the rear of the bubble which was accessed by a circular staircase.

Following the oil crisis of the early 1970s, many airlines opted for foregoing the upstairs lounge and replacing this with extra seating to try and offset the higher fuel-driven operating costs.

The fast-paced growth of long-distance travel that was present in the 1960s drove two different trains of thought. Firstly how to move more people at once, and secondly how to move them more quickly.

With this in mind, the Boeing 747 was designed to carry large amounts of passengers. To allow for contingencies should the second become the future focus of commercial aviation, and we have to remember that supersonic flight was a reality at that time, the 747was also designed to be capable of carrying large volumes of cargo when configured as a freighter.

For this reason, the flight deck was housed in a bubble atop the main fuselage so as to enable a nose cargo door to be installed with a clear passage to the main deck. Should the market fall out of the high-volume passenger market due to Super Sonic Transport (SST) becoming the norm, then the 747 still had a market as a freighter.

The introduction of this much larger aircraft caused its own headaches for airport operators, for instance, runways had to be strengthened. Boeing for their part equipped the 747 with 18 wheels to enable a better distribution of weight. Terminal gate areas also had to be widened to accommodate the greater wing span, as well as passenger assembly areas now needed to be able to accommodate two to three times as many passengers as previously.

The Boeing 747 design was such a departure from the technology then in use that it took 75,000 engineering drawings and 15,000 hours of wind tunnel testing to come up with the first Boeing 747 prototype. Five aircraft then completed a ten-month 1,500 flying hour test program to gain certification for commercial operation.

It is interesting to note that the entire Boeing 747 fleet has logged 42 billion nautical miles (77.8 billion kilometers) which is equivalent to 101,500 return trips from Earth to the Moon. On the trips that make up that distance, more than half of the Earth's population has been carried, a total of 3.5 billion people.

The 747 8, the final model, is an evolutionary follow-on from the 747 400, rather than a revolutionary jump. Some of the new technologies used in the Boeing 787 Dreamliner have also been used in the 747 8, such as LED lighting in the cabin, larger passenger windows, and partial fly-by-wire systems. Fly-by-wire means that control input on the flight deck is transmitted by electric wire to actuators on the control surfaces rather than heavier hydraulic systems.

The fuselage length of the Boeing 747 has not changed since 1968 other than the shorter Boeing 747SP (Special Performance) which was popular with a few airlines that required longer-range aircraft like QANTAS, Iran Air, and South African Airways. The Boeing 747 8 is only the second to depart from the standard fuselage length by adding 5.6 metres (18.3 ft) to achieve an overall length of 76.25 metres (250ft 2in). This makes Boeing 747 8 the longest passenger liner in the world-beating Airbus A340-600 by 7.5cm (3in), and the largest passenger liner ever produced in the USA.

If building the world’s biggest airliner was going to be a challenge, then no less so was the challenge of building a plant large enough to accommodate the assembly line.

After investigating sites in 50 different cities around the United States, Boeing settled on a site around 48 Km(30 miles) north of Seattle, Washington in June 1966. The location was adjacent to Paine Field, a military base near Everett. Once the 315.65-hectare (780 acres) site was acquired, it had to have 3.1 million cubic metres (4 million cubic yards) of soil moved before the building could commence.

Construction of the plant, which is the largest building by volume ever built, had to be completed urgently as the development of the Boeing 747 was gathering pace. The first mock-up of the Boeing 747 was completed before the roof of the plant was even completed.

Ever since 1914 when Henry Ford pioneered the moving assembly line for the construction of his Model T, this process has been the mainstay of mass production in the automotive and other industries. The concept has remained basically unchanged in the ensuing years other than technological advancements.

The gains in efficiency, accuracy, and speed to completion are self-evident. Boeing implemented such a process for the assembly of the Boeing 747. The design of the process is quite mind-boggling, and it is constantly being re-evaluated. Over the last decades software simulation programs have been instrumental in perfecting processes and enabling the movement from a 24-day construction period per unit toward a target of 18 days. Having the processes in order so that workers are not trying to access the same area to perform different tasks.

For several decades technicians worked from stations located along the walls of the factory and stepped up to the aircraft as it entered their area. Now they stay with the aircraft as it moves with all the necessary tools at hands reach. Engineers are a radio call away.

This methodology does a lot to reduce workshop clutter and inventory, thereby improving speed and cost.

In the 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 few 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 a 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.

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 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 thorough 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. This is known as Foreign Object Debris(FOD). Any of these that ended up falling in the wrong place could spell disaster through power short-outs or similar.

Once 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 onboard flight system and electrics have been tested and now the engines need to be mounted. Each $20 million engine weighs 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. A 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 throughout 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.

The design and building of the Boeing 747 was an audacious leap forward in aviation. The demand to relieve congestion at airports struggling with the influx of a growing travelling public was to be solved by offering fewer aircraft with higher carrying capacity. An aircraft with a carrying capacity double that of the existing workhorses, theBoeing 707andDouglas DC8, was required. Thus the Jumbo Jet was born. Let's take a look at the Boeing 747 Specs to better understand this Queen of the Skies.

Strangely enough, it wasn't the extra carrying capacity that attracted early customers of the aircraft, but longer range capabilities compared to other aircraft of the day.

The ability to consider designing such a large aircraft was made possible by the introduction of the High By-pass Turbo Fan engines that were able to deliver much higher thrust at a much-reduced fuel burn rate compared to pure jets in use at the time.

The four-engined Boeing 747 was designed to be the safest airliner so far built. Redundancy was in place for systems such as hydraulics, where a backup was available should the main system fail. There were dual control surfaces to enable the continued control of the aircraft should any of the surfaces fail. There were four main landing gear bogies each with four wheels. This was not only to spread the weight of the aircraft more evenly, but the 747 was capable of landing on two opposing bogies if necessary.

Everything about the 747 compared to other aircraft in use at the time of its initial launch, was on a grand scale. For instance; 147,000 pounds (66,150 kg) of high-strength aluminium is used in its construction, 171 miles (274 km) of wiring along with 5 miles (8 km) of tubing is used, and six million parts are used, half of which are fasteners.

In 1963 Boeing was among a group of plane makers that were competing for a military contract to build a very large transport. One of the main requirements for the military transport designwas for a nose loading cargo door with clear access to the main deck. The Boeing design featured a bubble atop the fuselage forward of the wing leading edge.

The contract went to Lockheed and General Electric to build what was to become the C5 Galaxy.

During this time, commercial aviation was growing at a rapid pace. The jet age was finding its feet with the very popular Boeing 707 and Douglas DC8 being the workhorses of the day. Juan Trippe of Pan Am, one of Boeings biggest customers, approached Boeing to press them to look at building an aircraft twice the size of the 707 and DC8. Trippe advocated that a larger aircraft would be the solution to the congestion at airports, reducing the number of relatively smaller aircraft required to move the same amount of people.

In 1965 Boeing put together a design team to work on the new airliner which was already given the Boeing 747 designation. The proposal Boeing had put forward for the military transport, the CX-HLS, was taken as a starting point. Some features were retained, but others such as the high-wing design were discarded. The design also had to be future-proof.

At this time in aviation, it was felt that supersonic travel had every chance of becoming the norm, so Boeing had to take an each-way bet. The design team for the Boeing 747 had to come up with an aircraft that met the requirements of airlines that wanted mass passenger movement, but at the same time had the ability to be an effective freighter.

Pan Am became the launch customer for the Boeing 747 in April 1966 by ordering 25 Boeing 747 100s. Being involved from the beginning of the design and development of the Boeing 747, Pan Am influenced these phases more than any other airline before or since.

Initial designs of the 747 called for a twin-deck aircraft, with both decks running the full length of the fuselage. This gave a very effective increase in capacity, however, the ability to evacuate two decks of passengers was found to be not possible within the recommended 90-second limit. Boeing opted for a single main deck which was then widened from the standard economy configuration of the day of six across, three and three, with a single aisle to a twin-aisle layout with seating ten across in a three-four-three configuration.

One of the main enablers that made such a larger aircraft possible was the advent of high-bypass turbofan engines. General Electric applied the principle to the C5 Galaxy project. The high bypass turbofan delivered twice the power of turbojets which were in use at the time and used one-third less fuel. Pratt and Whitney were also working on this concept and in 1966 Pan AM, Boeing and Pratt and Whitney agreed to develop the JT9D as the powerhouse for the 747.

The Boeing 747, since its inception in 1968, has been the workhorse for many of the world’s airlines.

Various improvements have been made to the basic design over the years as technology has advanced as well as the demands of the travelling public. For four decades the 747 reigned as the largest passenger airliner in the skies.

Global trends such as the advent of Low-Cost Carriers and higher fuel and other operating costs started to put pressure on plane makers to sharpen their pencils and work towards new designs that would not only be more fuel efficient but also comply with stricter noise reduction levels demanded at so many airports today.

In the 1990s and into the new century, Boeing investigated different options such as the 747 500X and 747 600X which was a stretched version of the 747 using a derivative of theBoeing 777wing. This was publicised at the Farnborough Airshow of 1996 but attracted little interest. The idea was shelved.

In 2000 Boeing offered a 747X which was a less dramatic change to the basic model with a stretched fuselage of some 263 ft (80.2 m). The wing span would be increased by inserting a segment at the wing root bringing the span to 229 ft (69.8 m). The pressure was on to compete with the proposed solution from Airbus, theAirbusA380.

At the time of its introduction, the Boeing 747 was radically different from anything that had previously been offered to the travelling public. Yes, Boeing had previously offered a twin-deck aircraft in the propeller-driven Stratocruiser, but the 747s upper deck was not originally designed to boost passenger seating so much as being a by-product of the elevated flight deck.

The 747 was the first wide-body commercial aircraft. Where the standard set by the incumbent intercontinental jets; the Boeing 707 and Douglas DC8, was to have an economy (coach) cabin layout of 3 seats either side of a single aisle, the 747 boasted twin aisles with 3 seats on each window side and 4 seats in the centre. This changed the look and feel of travel forever. The feeling of space in the larger cabin made long flights a bit more comfortable and less claustrophobic.

Initially many airlines opted to use the upstairs bubble behind the flight deck as a first-class lounge. The area typically featured casual seating with a bar as shown in the Continental Airlines pictures above. As a result of the oil crises in the early 1970s, many airlines looked for ways to maximise revenue to cover the increased fuel costs. The upstairs bubble was converted to paid seating. Business Class was also introduced as a compromise between First and Economy (Coach) class, and often airlines would offer the bubble as their Business Class cabin.

As technology has improved along with changes in styles and fashions, so too the aircraft cabin selections of most airlines have. Gone now are the single large movie screens which adorned the front of each cabin. These have been replaced by most mainstream airlines with individual seat-back screens or screens that can be stowed away into a seat arm. Passengers are now able to make selections from a suite of entertainment options brought to their own individual screens.

Toward the end of the life of the Boeing 747-400 many airlines were still heavily committed to the 747s in their fleets which still served them very well. In an effort to maintain their attractiveness to the travelling public, airlines, like QANTAS in Australia, had their 747-400s refurbished in styles influenced by Boeings’ new Dreamliner concept.

The benefits included a single beam seat design allowing more leg space in economy. Carbon fiber seat backs reduced weight and allowed for a thinner seat. Soft lighting and contoured panels made for a more spacious feeling cabin and offered a competitive comparison to newer jets being produced at that time.

On entering the new Boeing 747 8 Intercontinental, passengers will immediately know they areon a new aircraft. The interior concept is very much in line with the modern styles of theBoeing 787 Dreamliner. The airy swept-up Boeing Sky architecture gives a feeling of space.

The use of LED lighting, aside from the functional weight advantages as well as longevity, offers the ability to have smooth light transitions offering a more calm and soothing environment. The feeling is of being outdoors, the lighting and the sense of space. The 747 8 Intercontinental takes the technology and designs that make the Boeing 787 Dreamliner the sought-after aircraft of choice with passengers and runs with it.