Features
The 787 features lighter-weight construction. Its materials (by weight) are: 50% composite, 20% aluminum, 15% titanium, 10% steel, 5% other.[90] Composite materials are significantly lighter and stronger than traditional aircraft materials, making the 787 a very light aircraft for its capabilities.[91] The 787 will be 80% composite by volume.[92] Each 787 contains approximately 35 tons of carbon fiber reinforced plastic, made with 23 tons of carbon fiber.[93] Composites are used on fuselage, wings, tail, doors, and interior. Aluminum is used on wing and tail leading edges, titanium used mainly on engines with steel used in various places.[90]
The longest-range 787 variant can fly 8,000 to 8,500 nautical miles (14,800 to 15,700 km), enough to cover the Los Angeles to Bangkok or New York City to TaipeiMach 0.85[94] (561 mph, 903 km/h at typical cruise altitudes). routes. It will have a cruise speed of
The 787 will seat 240 in two-class domestic configuration, with a 46-in (116.8 cm) pitch for first class and a 34-in (86.4 cm) pitch for coach class. 296 passengers can be seated in a high-density 3+2+3 / 2+4+2 coach arrangement with 36-in (91.4 cm) Business and 32-in (81.3 cm) Coach pitch. Up to 234 passengers may be seated in a three-class setup that uses 61-in (154.9 cm) pitch in First Class (2+2+2 or 1+2+1), 39-in (99 cm) pitch for Business (2+3+2 or 2+2+2) and 32-in (81.3 cm) for Coach (2+4+2).[95] Cabin interior width is approximately 18 feet (547 cm) at armrest,[95] and was increased by 1 inch (2.5 cm) over what was originally planned.[96] The 787's interior cabin width is 15 in (38 cm) greater than that of the Airbus A330 and A340,[97] but 5 in (13 cm) narrower than the A350-800 XWB.[98] For economy class in 3+2+3 or 2+4+2 arrangements, seat-bottom widths will be 18.5 in (47 cm), comparable to that found on the Boeing 777, and recommended by detailed passenger ergonomics studies. For 3+3+3 and 2+5+2 maximum passenger density layout, the seat widths would be approximately 17.2 in (43.7 cm), approximately the same as those found on the Boeing 737. The vast majority of airlines are expected to select the 3+3+3 configuration on the 787.[99] (See wide-body aircraft for a comparison of cabin widths and seating).
The cabin windows are larger than all other in-service civil air transports (27 cm by 47 cm), with a higher eye level, so passengers can maintain a view of the horizon. Electrochromism-based "auto-dimming" (smart glass) reduces cabin glare while maintaining transparency. These are to be supplied by PPG.[100] Light-emitting diode[101] cabin lighting (three color) will be used instead of fluorescent tubes, allowing the aircraft to be entirely 'bulbless' and have 128 color combinations. (LED)
A version of Ethernet—Avionics Full-Duplex Switched Ethernet (AFDX) / ARINC[102]GUI widget toolkit (Cockpit Display System Interfaces to User Systems / ARINC 661).[103] The Lockheed Martin Orion spacecraft will use a glass cockpit derived from Rockwell Collins' 787 flight deck.[104] The 787 flight deck includes two head-up displays (HUDs) as a standard feature.[105] Like other Boeing airliners, the 787 will use a yoke instead of a side-stick. 664—will be used to transmit data between the flight deck and aircraft systems. The flight deck features LCD multi-function displays, all of which will use an industry standard
The internal pressure will be increased to the equivalent of 6000 feet (1800 m) altitude instead of the 8000 feet (2400 m) on conventional aircraft. According to Boeing, in a joint study with Oklahoma State University, this will significantly improve passenger comfort.[106][107] Higher humidity in the passenger cabin is possible because of the use of composites (which do not corrode). Cabin air is provided by electrically driven compressors using no engine bleed air.[108] An advanced cabin air-conditioning system provides better air quality: Ozone is removed from outside air; HEPA filters remove bacteria, viruses and fungi; and a gaseous filtration system removes odors, irritants and gaseous contaminants.[90]
Bleedless turbofans imply the elimination of superheated air conduits normally used for de-icing, aircraft power, and other functions. These systems are to be replaced by an all-electrical system.[3] Another new system is a wing ice protection system provided by Ultra Electronics Controls Division of the UK that uses electro-thermal heater mats attached to the aircraft slats, special electrical harnesses for transferring the electrical power to the heater mats as well as system control and power switching technology.[citation needed]
An active gust alleviation system, similar to the system that Boeing built for the B-2[107] Boeing, as part of its "Quiet Technology Demonstrator 2" project, is experimenting with several engine noise-reducing technologies for the 787. Among these are a redesigned air inlet containing sound-absorbing materials and redesigned exhaust duct covers whose rims are tipped in a toothed pattern to allow for quieter mixing of exhaust and outside air. Boeing expects these developments to make the 787 significantly quieter both inside and out.[109] bomber, improves ride quality during turbulence.
Boeing engineers designed the 787 interior to better accommodate persons with mobility, sensory, and cognitive disabilities. For example, a 56-inch by 57-inch convertible lavatory includes a movable center wall that allows two separate lavatories to become one large, wheelchair-accessible facility.[110]
[edit] Technical concerns
[edit] Engine interchangeability
The two types of engines compatible with the 787 will use a standard electrical interface, potentially allowing an aircraft to be fitted with Rolls-Royce or GE engines at any time. This flexibility will allow an airline to switch from one engine manufacturer to another in order to take advantage of technological developments or to facilitate maintenance. Boeing's goal is to make changing engine types as simple as a standard same-manufacturer replacement.
However, ILFC's Vice President of Marketing, Marty Olson stated that swapping engines produced by different manufacturers could take as long as 15 days - thus making the idea of multi-manufacturer engine changes economically infeasible. "You’d have to take all the pylon, everything from the wing down, off," Olson said. He went on to complain that Boeing is still promoting the 24-hour change in spite of promises to alter their marketing. Current aircraft can have engines changed to those of a different manufacturer but this rarely happens due to the costs involved. Boeing's response is that the design is not yet finalized and 24 hours remains their goal.[111]
[edit] Composite fuselage
The 787's all-composite fuselage makes it the first composite airliner in production. While the Boeing 777 contains 50% aluminum and 12% composites, the numbers for the new airplane are 15% aluminum, 50% composite (mostly carbon fiber reinforced plastic) and 12% titanium. Each fuselage barrel will be manufactured in one piece, and the barrel sections joined end to end to form the fuselage. This will eliminate the need for about 50,000 fasteners used in conventional airplane building. According to the manufacturer the composite is also stronger, allowing a higher cabin pressure during flight compared to aluminum.[112] It was suggested by many, such as former Boeing senior engineer Vince Weldon, that the risks of having a composite fuselage have not been fully assessed and should not be attempted.[113] It was also added that carbon fiber, unlike metal, does not visibly show cracks and fatigue.[114] Boeing has dismissed such notions, insisting that composites have been used on wings and other passenger aircraft parts for many years and they have not been an issue. They have also stated that special defect detection procedures will be put in place to detect any potential hidden damage.[115]
Another concern arises from the risk of lightning strikes.[116] The 787 fuselage's composite could have as much as 1,000 times the electrical resistance of aluminum, increasing the risk of damage during a lightning strike.[117] Boeing has stated that the 787's lightning protection will meet FAA requirements.[113] FAA management is planning to relax some lightning strike requirements, which will help the 787.[118]
In 2006, Boeing launched the 787 GoldCare program.[119] This is an optional, comprehensive life-cycle management service whereby aircraft in the program are routinely monitored and repaired as needed. This is the first program of its kind from Boeing: Post-sale protection programs are not new, but have usually been offered by third party service centers. Boeing is also designing and testing composite hardware so inspections are mainly visual. This will reduce the need for ultrasonic and other non-visual inspection methods, saving time and money.[120]
According to Boeing Vice President Jeff Hawk, who heads the effort to certify the 787 for airline service, a crash test involving a vertical drop of a partial fuselage section from about 15 feet onto a one inch-thick steel plate went ahead as planned August 23, 2007 in Mesa, Arizona.[121][122] Boeing spokeperson Lori Gunter stated on September 6, 2007 that results matched what Boeing's engineers had predicted. As a result the company can model various crash scenarios using computational analysis rather than performing more tests on actual pieces of the plane.[123][124] However, it has also been suggested by a fired Boeing engineer that in the event of a crash landing, survivable in a metal plane, the composite fuselage could shatter and burn with toxic fumes.[113]
[edit] Weight issues
Boeing had been working to trim excess weight since assembly of the first airframe began in 2006. This is typical for new aircraft during their development phase. The first six 787s, which are to be used as part of the test program, will be overweight according to Boeing Commercial Airplanes CEO Scott Carson. After the flight test program, these aircraft will be delivered to airline customers All Nippon Airways, Northwest Airlines and Royal Air Maroc at speculated deeper than usual discounts.[125] The first 787 is expected to be 5,000 lb (2,270 kg) overweight. The seventh and subsequent aircraft will be the first optimized 787s and are expected to meet all goals.[126] Boeing has redesigned some parts and made more use of titanium.[37] According to ILFC's Steven Udvar-Hazy, the 787-9's operating empty weight is around 14,000 lb (6,350 kg) overweight, which also could be a problem for the proposed 787-10.[127]
In early 2009 a number of 787 customers started to publicly mention their dissatisfaction with the reduced specifications on the 787, specifically weight/range issues. Industry insiders have stated Boeing has reduced its range estimates for the 787-8 from 14,800-15,700 km to 14,150-15,170 km, a reduction of over 500 km. There have also been reports that this led Delta to delay deliveries of 787s it inherited from Northwest in order to take later planes which may be closer to the original estimates. Other airlines are suspected to have been given discounts to take the earlier models.[128] Shanghai Airlines stated in March 2009 it wished to either delay or cancel its first order. Boeing expects to have the weight issues addressed by the 21st production model.[129]
In May 2009, a press report indicated that a 10%-15% range reduction for early 787-8 aircraft is anticipated due to these planes being about 8% overweight. This means a range of about 6,900 nmi (12,800 km) instead the originally promised 7,700 to 8,200 nmi (14,800-15,700 km). Substantial redesign work is expected to correct this, which will complicate increases in production rates.[82] Boeing confirmed on May 7 that early 787s would be heavy and is working on weight reductions. The company stated the early 787-8s will have a range of almost 8,000 nmi (14,800 km).[130]
[edit] Computer network vulnerability
In January 2008, previous Federal Aviation Administration concerns came to light regarding protection of the 787's networks from possible intentional or unintentional passenger access.[131][132] The computer network in the passenger compartment, designed to give passengers in-flight internet access, is connected to the airplane's control, navigation and communication systems.[131]
Boeing says various hardware and software solutions are employed to protect the airplane systems including air gaps for the physical separation of the networks, and firewalls for their software separation. Measures are provided so data cannot be transferred from the passenger internet system to the maintenance or navigation systems. As part of certification Boeing plans to demonstrate to the FAA that these provisions are acceptable.[131]
