|The 787 makes its debut. Click to enlarge.|
Boeing rolled out the first 787 Dreamliner—the first of its new family of mid-size commercial jetliners, the first with composite material primary structures—on Sunday. The version making the debut was the 787-8. With a passenger capacity of 210 to 250 and a range of 7,650 to 8,200 nautical miles (14,200 to 15,200 kilometers), the 787-8 will use 20% less fuel than any other current airplane of its size.
Boeing has already committed to a 787-3 version optimized for shorter routes, and the 787-9, a slightly longer version of the airplane that will carry more people on longer range flights. ANA and Japan Airlines have ordered 43 787-3s for domestic operations in Japan. Deliveries of this model will start in early 2010. Air New Zealand, Singapore Airlines, Continental, and Qantas are among the 11 customers with orders for 115 787-9s.
A still-to-be-defined 787-10 will follow by around 2013. The 787 Dreamliner has become the fastest-selling commercial airplane in history. As of 7 July, Boeing had logged 677 orders from 47 customers for the 787, with Air Berlin posting the final pre-rollout order for 25. Overall, the 787 Dreamliner order book is currently valued at more than $110 billion.
|The 787 makes extensive use of composites. Click to enlarge.|
The new aircraft features a number of new design features including the extensive use of composites instead of aluminum for 50% of the primary structure of the plane—including the fuselage and wing. The main material is graphite combined with a toughened epoxy resin. The wings also use a titanium/graphite composite.
Building the fuselage from one-piece composite components (fuselage barrels) eliminates 1,500 aluminum sheets and 40,000 - 50,000 fasteners, according to Boeing.
|The 787 uses one-piece composite fuselage barrels. Click to enlarge.|
Boeing anticipates increasing the composite content to 60% in coming versions. The reduced weight due to the use of composites contributes to the reduction in fuel consumption and to the reduction in noise.
Key system technologies featured in the 787 include:
Common core open systems architecture;
Advanced flight controls and an enhanced flight deck;
Power electronics cooling system;
Electric, rather than hydraulic, brakes;
Onboard maintenance system;
No-bleed systems architecture; and
Engines. GE and RollsRoyce are the designated engine suppliers for the 787. Each engine maker is delivering a new generation of engine for the 787: the GEnx from GE and the Trent 1000 from RollsRoyce. The launch 787 is equipped with the RollsRoyce engines.
Producing a range of thrusts from 53,000 - 75,000 lb, a single version of the Trent 1000 will be certified to power all variants of the 787, the 787–8, 787-3 and 787-9. ANA will begin operating the 787-8 in mid-2008 and will also introduce the short-range 787-3 variant in 2010. Air New Zealand will launch the 787-9 into service, also in 2010.
GE’s GEnx, which Boeing has also selected for the 747-8 version, has tested to 80,500 lb. of thrust. The engine features a front fan case and fan blades made of composites and a unique combustor called the Twin Annular, Pre-mixing Swirler (TAPS) combustor for enhanced NOx reduction.
In TAPS, air from the high-pressure compressor is directed into the combustor through two high-energy swirlers adjacent to the fuel nozzles. This swirl creates a more homogeneous and leaner mix of fuel and air, which burns at lower temperatures than in previous jet engine designs.
The lower temperatures generated in the TAPS combustor results in significantly lower NOx levels. For example, at comparative thrust levels, GEnx NOx emissions will be more than 30% lower than the NOx emissions of GE’s highly popular CF6 engines powering commercial widebody aircraft today. The GEnx emissions goal at entry into service is to be about 50% below the new NOx limits to be established in 2008.
|The 787 offers reduced fuel consumption. Click to enlarge.|
Fuel consumption. The combination of new materials, increased electrification, design and engines all lead to the expected reduction in operation fuel consumption of 20% compared to current aircraft of a comparable size.
Boeing calculates that the 787 will deliver fuel consumption of approximately 2.4 l/100 passenger-kilometers, assuming average modal load factors.
In its 2002 report, The Environmental Effects of Civil Aircraft in Flight, the UK’s Royal Commission on Environmental Pollution (RCEP) noted that in terms of fuel use:
Allowing for the effects...leading to a factor of around 3 [times greater] in the radiative forcing of carbon dioxide from aircraft compared to terrestrial transport, travelling by air is broadly equivalent to one or two people travelling in a passenger car. The Commission has already pointed out in its Eighteenth and Twentieth Reports that passenger cars are more environmentally damaging than any other form of surface transport. The comparisons presented here show that air transport is in the same category, albeit with a much better safety record.
One of the concerns voiced about the advent of the new, more fuel-efficient aircraft (as well as its apparent popularity, as orders are outpacing analysts’ earlier projections) is the potential for a “rebound effect” similar to that seen with increases in fuel efficiency in light-duty vehicles—i.e., the decrease in fuel consumption (and thus, operating costs) leads to an increase in vehicle miles travelled.