Responding to the overwhelming preference of airlines around the world, Boeing Commercial Airplanes’ recently launched the 787 Dreamliner, a super-efficient aeroplane. An international team of top aerospace companies is building the airplane, led by Boeing at its Everett facility near Seattle in the US. Over 50 of the world’s most capable top-tier supplier partners are working with Boeing to bring innovation and expertise to the 787 program.
The 787 program was launched in April 2004 with a record order from Japanese airline All-Nippon Airways (ANA). Fifty-nine customers from six continents of the world have placed orders for 854 aeroplanes valued at over US$175 billion, making it the most successful twin-aisle launch of a new commercial aeroplane in Boeing’s history. The first flight of the 787 Dreamliner took place on December 15, 2009 and ANA took their first delivery of the 787 on 25 September 2011.
The 787-8 Dreamliner will carry 210 – 250 passengers on routes of 7,650 to 8,200 nautical miles (14,200 to 15,200 kilometres), while the 787-9 Dreamliner will carry 250 – 290 passengers on routes of 8,000 to 8,500 nautical miles (14,800 to 15,750 kilometres).
In addition to bringing big-jet ranges to mid-size aeroplanes, the 787 provides airlines with unmatched fuel efficiency, resulting in exceptional environmental performance. The aeroplane uses 20 per cent less fuel than today’s similarly sized airplanes.
Passengers will also see improvements on the 787 Dreamliner, from an interior environment with higher humidity to increased comfort and convenience.
Boeing, along with universities from around the world, has embarked on numerous studies to understand the effects of altitude, humidity, air contaminants, lighting, sound and space on passengers. In addition, the company has studied how these factors play together to develop combinations to create the best overall experience. Findings have helped lead to significant improvements on the 787.
Today’s aeroplanes are pressurised to a typical cabin altitude of 6,500 to 7,000 feet with a maximum certification altitude of 8,000 feet. The advanced composite materials used on the 787’s fuselage do not fatigue, which allows for lower altitude levels. (The fuselage is an aircraft’s main body section that holds crew and passengers or cargo.)
Studies at Oklahoma State University explored the effect of altitude on passengers. After testing at various altitudes, it became clear that lowering the cabin altitude to 6,000 feet provided meaningful improvements. Furthermore, lowering the cabin altitude below 6,000 feet provided almost no further change. Based on that knowledge, the 787 is pressurised (increased pressure to create the lower altitude) to a maximum cabin altitude of 6,000 feet.
In cooperation with Denmark Technical University, Boeing challenged the assumption that simply increasing humidity would alleviate complaints about dryness on aeroplanes. The study found that humidity is not the only factor driving the symptoms associated with dryness – like throat and eye irritation, headaches and occasional dizziness. In fact, the most effective technology in reducing such symptoms is the introduction of a new gaseous filtration technology. Combining the filtration technology with increased humidity offers the best solution for passenger well-being.
By increasing the humidity and adding new filtration technologies, studies show the number of passengers experiencing the symptoms associated with dryness can be reduced. Additionally, the improvements in cabin altitude combine with humidity and cleaner air to create an overall improvement in passenger comfort.
Boeing also surveyed passengers on their reaction to different window options and the results clearly showed, unsurprisingly, that passengers prefer larger windows.
From an engineering point of view, however, larger windows have always been a challenge because the loads carried by the aeroplane structure are easier to deal with if the fuselage has fewer, or smaller, cutouts like doors and windows. But, because the fuselage on the 787 Dreamliner is constructed of advanced composite materials, rather than aluminum, it can handle the larger window cutouts. The 787 has larger windows than any current commercial airplanes, offering passengers seated throughout the airplane a commanding view of the horizon.
More attention has been paid to both the level and quality of noise within the cabin since noise can contribute to a passenger’s sense of fatigue. Boeing and its partners have developed innovative solutions to address this issue, including the use of serrated ‘chevrons’ as part of the nacelle design. (The nacelle is the cover housing that holds engines, fuel, or equipment on an aircraft.) These chevrons and other technologies lower noise both inside and outside the cabin, making it quiet for communities living near the airport, ground crews and passengers.
As airport community neighbours know, reducing the noise created by aeroplanes during takeoff and landing is an important measure of environmental performance. As with its record of continuously reducing fuel use and thus reducing emissions, Boeing has worked to reduce the sound footprint – the distance across which disturbing noise is heard.
The 787 Dreamliner uses a number of new technologies – most importantly, acoustically treated engine inlets and chevrons, the distinctive serrated edges at the back of the engine, and other special treatments for the engines and engine casings – to ensure that all sound of 85 decibels (about the level of loud traffic heard from the side of the road) never leaves the airport boundaries. In fact, the noise footprint of the 787 is over 60 per cent less than those of today’s similarly sized aeroplanes.
Boeing’s commitment to improving the environmental performance of its products is based on a deeply held belief that doing the right thing for the environment is good business. This is especially true for a manufacturer of airplanes because one of the many reasons that people choose to fly is to enjoy the rich variety of environmental wonders around the world.
Four key technologies contribute to the 787 Dreamliner’s impressive 20 per cent improvement in fuel use as compared to today’s similarly sized aeroplane. New engines, increased use of light weight composite materials, more-efficient systems applications and modern aerodynamics each contribute to the 787’s overall performance. As a result, with reduced fuel consumption comes an equivalent reduction in carbon dioxide emissions.
The mission capability of the 787 Dreamliner also provides an environmental advantage, allowing airlines to offer more direct flights connecting mid-sized cities. A more direct route uses less fuel, which means fewer emissions. Likewise, fewer takeoffs and landings reduce the total noise footprint.
The key to the exceptional performance of the 787 Dreamliner is a suite of new technologies developed and applied on the aeroplane. Composite materials make up 50 per cent of the primary structure of the 787 including the fuselage and wing.
Because the 787 is made primarily of carbon-fibre composite material, which is trimmed like cloth, manufacturing processes produce less scrap material and waste. The result is an overall manufacturing and maintenance process that produces less waste and uses fewer harmful chemicals and agents.
New engines from General Electric and Rolls-Royce are used on the 787. Advances in engine technology are the biggest contributor to overall fuel efficiency improvements. The new engines represent a nearly two-generation jump in technology for the middle of the market.
The design and build process of the 787 has added further efficiency improvements. New technologies and processes have been developed to help Boeing and its supplier partners achieve the efficiency gains. For example, manufacturing a one-piece fuselage section has eliminated 1,500 aluminum sheets and 40,000 – 50,000 fasteners.
Boeing is also working with companies around the world to ensure the processes required to allow the 787 to be recycled when it is eventually retired are in place. Though the first retirements are likely 30 to 40 years away, it is important that work be done today to prepare for this event.
It is the combination of its historic commitment to improving the environmental performance of its aeroplanes and a specific life-cycle approach to designing its newest aeroplane that has allowed Boeing to create a super efficient commercial jet transport. The 787, in part because of its improved environmental performance, is the most successful launch of a new aeroplane in commercial aviation history. Airlines of the world are choosing to purchase the 787 because they share in Boeing’s commitment to the environment. Likewise, passengers will be able to choose an aeroplane that offers more comfort and better environmental performance. www.boeing.com