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Airbus A350 | Aviation Week Network


The A350 XWB is a series of twin-engine, widebody airliners produced by European manufacturer Airbus. First launched in October 2005, the A350 was originally designed to retain the fuselage cross-section of the company’s A330 and A340. However, following pressure from customers—notably International Lease Finance Corp. (ILFC) chairman and CEO Steven F. Udvar-Hazy—the A350 series that was ultimately developed and certified was a clean-sheet series of airplanes that was unveiled in July 2006, industrially launched in December 2006 and which was initially planned to include four passenger variants—including the -800, -900 and -1000—and a freighter variant. Another difference between the original plans for the A350 and what was ultimately brought to market was the entry-into-service date, with Airbus planning for the original airframe to enter service in 2010. In contrast to that initial timeline, the first A350 airframe—manufacturing serial number (MSN) 1, a -900—was rolled out of Airbus’ manufacturing facilities at Toulouse-Blagnac Airport in France in February 2013. That airframe, registered as F-WXWB, subsequently performed the type’s first flight on June 14, 2013, a flight that lasted 4 hr. 5 min. Following a flight-test program that included more that 2,600 flying hours, the A350-941 was certified by the European Aviation Safety Agency (EASA) in September 2014. Subsequently, the larger A350-1000 was rolled out in 2016, with its 4 hr. 18 min. first flight—performed by airframe MSN059, registered as F-WMIL—taking place on Nov. 24, 2016. In addition to the base variants of the A350, Airbus has also developed an extended-range version of the -900 that is marketed as the A350-900 Ultra Long Range (ULR), an airplane made its first flight on April 23, 2018. Regardless of the differences between the variants of the A350—as well as between the standard and ULR versions of the -900—all A350s are powered by Rolls-Royce Trent XWB engines, with the airframe’s type certificate held by Airbus S.A.S. of Blagnac, France.

A350 Variant

EASA Certification Date

A350-941

Sep. 30, 2014

A350-1041

Nov. 21, 2017

Cabin Configuration and Size

In comparison to the 222-in. (18 ft. 6 in.) fuselage diameter of the A330 and A340-series airframes, the A350 increases that specification by 13 in. to 235 in. (19 ft. 7 in.). Other cabin dimensions of the A350-900 include a length of 167 ft. 5 in. and maximum width 18 ft. 5 in., with the latter specification retained and former specification increased to 190 ft. 5 in. on the -1000. As noted in the table below, according to the type’s EASA type certificate data sheet (TCDS), both the -900 and -1000 variants have a maximum passenger seating capacity of 440. In contrast to that maximum certified capacity, the -900 is advertised as being able to accommodate between 300 and 350 passengers in a typical three-class configuration, a range that is increased to between 350 and 410 passengers in such a configuration on the -1000.

Beyond its dimensions and passenger seating capacities, the A350 cabin also includes the Airspace by Airbus cabin, a “cabin concept” that is described by Airbus as focusing on four attributes: ambience, comfort, design and service. With regard to the comfort of the cabin, the manufacturer notes the size of the fuselage cross-section and that role that it plays in the amount of space available to each passenger. To that end, the fuselage cross-section is promoted as allowing operators to install “the widest seats of any jetliner in its category,” with the width of seats being 18 in. in a nine-abreast configuration, in comparison to the “1960s-era 17-in. seat standard.” In addition to the size of the cabin and its impact on passenger comfort, the lighting and noise level of the A350 cabin is also promoted, with the noise level described as being the quietest among twin-aisle airplanes. The combination of the airframe’s cabin noise level, light-emitting diode (LED) lighting and seat width is also touted as “minimi[zing] the effects of jetlag.” Passenger fatigue is further decreased by the ability of the airframe to have a cabin altitude of as low as 6,000 ft. at the -900’s 43,100-ft. maximum operating altitude—an altitude that is touted as being “25% less than in aluminum-fuselage aircraft”—as well as by the “draft-free air conditioning system,” the combination of which “leads to a less dry cabin environment.” That cabin altitude is enabled by the fact that the pressurization of the cabin has been increased “to as much as 9.4 psi.” In comparison to the 787, Airbus states that the A350’s air conditioning and cabin temperature management systems offer “20% more fresh air, with the entire cabin renewed every two to three minutes.” Finally, the ability of the “state-of-the-art ambient LED lighting system” to simulate different times of day also helps “passengers acclimatize to different time zones.”

Cargo Capacity

Beneath the cabin, the A350-900 is able to carry up to 36 LD3 containers, while the maximum number of pallets that can be carried is 11. According to Airbus’ airport planning documents for the A350, the -900 has three cargo compartments—forward, aft and rear (bulk)—with the forward compartment able to accommodate 48,501 lb. in 3,062 ft.3 of volume. The aft compartment, with 2,447 ft.3 of volume, has a maximum load of 41,888 lb., while the rear (bulk) cargo compartment is limited to 7,646 lb. in 403 ft.3. On the A350-900ULR, however, the forward cargo hold is “deactivated,” with “no cargo operation possible.” The larger -1000 airframe increases the respective number of LD3 containers and pallets to 44 and 14, while the amount of cargo that can be accommodated in the 3,673-ft.3 forward cargo compartment is increased to 58,423 lb. Comparatively, the 3,062-ft.3 aft cargo compartment has a maximum load of 54,013 lb., while the capacity of the rear (bulk) compartment is actually decreased to 3,307 lb. in the same 403 ft.3 that is found on the -900.

Avionics

Flight crews operate the A350 using six 15-in. interchangeable, flat-panel displays that are set up in a landscape configuration and which are supplied by Thales. The configuration of those displays, which are largest displays found on an Airbus, includes two outboard information displays, as well as a primary flight and navigation display (PFD/ND) that is in front of each pilot. Of the two center displays, the top display represents the electronic centralized aircraft monitor (ECAM), which shows information such crew-alerting annunciations, engine instruments, and system displays. The bottom display is noted as providing “two multifunction displays” that can be “used for flight planning via a point-and-click interface.”                                                                                                                       

Mission and Performance

In comparison to its primary competition, Boeing’s 787 series, the A350 does offer slightly greater passenger capacity and range, according to publicly available figures from both manufacturers. Although Airbus does not currently offer an A350 variant that has a seating capacity comparable to the 787-8, the A350-900 and 787-9 are comparable in maximum passenger capacity, with the 787-9’s maximum certified capacity listed in the FAA TCDS as being 420. Furthermore, according to Boeing, the -9 is capable of accommodating 296 passengers in a two-class configuration, while the A350-900 is able to seat between 4 and 54 more passengers in a typical three-class configuration. According to Airbus’ airport planning documents for the A350, the standard seating capacity of the -900 in a two-class layout is 315, with 48 passengers accommodated in business class and 267 in economy class. Similarly, although the two and three-class capacities of the A350-1000 and 787-10 differ—with the latter advertised as being able to accommodate 336 passengers in a two-class configuration—the maximum certified seating capacities are the same (440). While Airbus promotes the -1000 as having the three-class capacity range noted above, the airport planning document for the type states that the standard seating capacity of the airframe in a two-class configuration is 369, with accommodations for 54 passengers in business class and 315 in economy class. With regard to range, the 787-9 and -10’s 7,635 nm and 6,430 nm respective capabilities are based on the typical two-class capacities noted above.

Comparison: A350 vs 787 Specifications

 

A350-941

A350-1041

787-9

787-10

Maximum Passenger Seating Capacity

440

420

440

Two-Class Seating Capacity

315/

173 (-900ULR)

369

296

336

Maximum Range (nm)

8,100

8,700

7,530

6,345

Engines (2X)

Rolls-Royce Trent XWB

General Electric GEnx-1B

Rolls-Royce Trent 1000

Maximum Takeoff Weight

(MTOW)(lb.)

617,295

696,661

560,000

Maximum Landing Weight

(lb.)

456,357

520,291

425,000

445,000

Wingspan

212 ft. 5 in.

197 ft. 3 in.

Length

219 ft. 2 in.

242 ft. 1 in.

206 ft. 1 in.

224 ft. 1 in.

Height

55 ft. 11 in.

56 ft.

55 ft. 10 in.

As is also noted above, the maximum operating altitude of the A350-900 is 43,100 ft., a limitation that is decreased to 41,450 ft. on the -1000. In contrast to those differing maximum operating altitudes, both A350 variants are limited to a maximum operating Mach speed (MMO) of 0.89 Mach. According to Airbus, the 8,100-nm range of the -900 and 8,700-nm range of the -1000 are based on the respective airframes carrying a “typical passenger load.”

Variants

A350 Specifications

 

A350-941

A350-1041

Maximum Passenger Seating Capacity

440

Typical Three-Class Seating Capacity

300-350

350-410

Maximum Range (nm)

8,100

8,700

Engines (2X)

Rolls-Royce Trent XWB

Engine Variant Takeoff Thrust Limit (lb.)

XWB-84

XWB-75

XWB-97

84,200

74,200

97,000

Maximum Takeoff Weight

(MTOW)(lb.)

617,295

696,661

Maximum Landing Weight

(lb.)

456,357

520,291

Wingspan

212 ft. 5 in.

Length

219 ft. 2 in.

242 ft. 1 in.

Height

55 ft. 11 in.

56 ft.

Trent XWB Engines

Both variants of the A350 are powered by Rolls-Royce’s Trent XWB engines, with the -900 certified to be equipped with two variants of that engine series (the XWB-75 and XWB-84) and the -1000 certified for one (the XWB-97). Described as being the sixth generation of the company’s Trent engine series, from a design perspective the Trent XWB is a three-shaft, high-bypass-ratio, axial -flow turbofan engine that features low, intermediate and high-pressure compressors that are “driven by separate turbines through coaxial shafts.” That design is touted as being “a unique, lightweight three-shaft design,” with the “module weight savings” of the engine amounting to 15%. In addition to weight savings, the Trent XWB is promoted as improving fuel efficiency, with the fuel consumption in comparison to the original Trent engine improved by 15%, an improvement that results in a cost savings of $2.9 million per airplane per year in fuel. Improvements in fuel efficiency are supplemented by aerodynamic efficiency improvements that are enabled through “the use of compressor blisk technology,” as well as an “optimized” internal air system that is marketed as reducing “core air demand and fuel consumption.” Furthermore, the Trent XWB’s combustor is touted for its reliability and capability to meet “current and future emissions targets.” Beyond the Trent XWB engines that power the A350, another Rolls-Royce engine—the Trent 7000—incorporates engine technology from the Trent XWB to power Airbus’ A330neo airframes.

A350 Improvements

Supplementing the advances incorporated into the Trent XWB engines, Airbus also promotes the A350 as featuring improvements in flight controls, materials, systems and wing design. With reference to materials, the fuselage and wings of both airframes incorporate carbon-fiber reinforced plastic (CFRP), which not only reduces weight and fuel burn, but also makes maintenance easier and increases the airframe’s “resistance to corrosion.” Overall, more than 70% of the A350 airframe is “made from of advanced materials” that include composites—representing 53% of the airframe—titanium and modern aluminum alloys. Carbon fiber—specifically, its advantages in fatigue and strength—enabled a more advanced wing for the A350, with the advanced materials more broadly allowing “designers to produce a higher-aspect-ratio wing” that reduces drag. Further described as “the most sophisticated airfoil yet on a commercial Airbus,” the advanced design of the A350’s wings also allows them to be both quieter and more efficient, with the latter attribute enhanced by the wing’s ability to adapt or morph while in flight. That ability to change makes it possible for the wings to maximize aerodynamic efficiency for each phase of flight, with the overall advances made to the airframe resulting in a 25% “advantage” in carbon dioxide (CO2) emissions, fuel burn and operating costs. Other features of the A350’s wings include a “31.9 deg. of quarter-chord sweep, 14-ft. scimitar-shaped winglets and spoilers that droop with flap extension to fully or partially seal the gap between the Fowler flaps and wing to reduce drag.”

A350-800

Unveiled alongside the -900 and -1000 was the smallest of the planned A350 airframes, the -800, a variant of the series that has since been cancelled by Airbus. According to the Airbus press release announcing the A350 series, the -800 was intended to be able to seat 270 passengers in a three-class configuration.

A350-900ULR

Launched in 2015 with an order from Singapore Airlines, the A350-900ULR improves on the -900’s range by 1,600 nm, making the ultra-long-range version of the -900 capable of a range of 9,700 nm. According to Airbus, that range gives this airframe the ability to fly “further in commercial service than any other aircraft.” Although the -900ULR does not include an increasd number of fuel tanks, changes were made in order to allow this version of the -900 to operate routes that exceed 20 hr. in duration. The primary modifications that enable the 1,600 nm increase in range involve the airframe’s fuel system, with those changes increasing the “fuel carrying capacity by [6,340 gal.] without the need for additional fuel tanks.” Modifications such as “the relocation of sensors in the fuel system” allow the -900ULR to carry 43,589 gal. of fuel and eliminate “the need for additional fuel tanks.” Supplementing the changes to the fuel system are aerodynamic changes made to the wing—including extensions of the winglets and wing-flap fairings, and changes to the wing twist—as well as the fact that the MTOW was increased to the 617,290-lb. (280 metric ton) maximum noted above from 606,276 lb. (275 metric tons). Beyond the -900ULR, those changes to the wing are now standard on the A350-900, while the 280-metric ton MTOW is available as an option.

A350-1000

The larger of the two A350 variants, the -1000, has a fuselage that is 22 ft. 11 in. longer than that of the -900, resulting in that variant having increased passenger capacity and range, while also increasing fuel efficiency in comparison to competing airplanes. Other distinctions between the variants of the A350 include the fact that the -1000 features modifications to the trailing edge of the its wing, has “new six-wheel main landing gears” and is certified to be powered by a higher-thrust variant of the Trent XWB. Indeed, with a thrust at takeoff of 97,000 lb., the Trent XWB variant that powers the -1000—the XWB-97—is promoted as being “the most powerful engine ever developed for an Airbus aircraft.” Beyond the benefits noted above in terms of fuel efficiency, the XWB-97 engines also allow for an increase in the amount of payload that can be carried and the range to which the airplane can be operated. In spite of those differences, there is a great deal of commonality between the -900 and -1000, including a common type rating for pilots and 95% common systems part numbers. Furthermore, as is the case with the -900, the -1000’s fuselage is “built with [CFRP],” with the cumulative effect of the technological advancements allowing the airplane to burn “25% less fuel than its nearest competitor.”

A350 Environmental Performance

Beyond the A350’s 25% reduction in CO2 emissions—which is measured on a per-seat basis—the airframe is also marketed as having nitrogen oxide (NOX) emissions that are 28% less than what is required by the Committee on Aviation Environmental Protection’s CAEP/6 standards. With regard to noise, the A350 is promoted as being the “quietest [airframe] in its class,” with the noise footprint reduced by 40% in comparison to prior-generation airplanes. Specifically, Airbus describes the A350-900 as being certified at 21 effective perceived noise level in decibels (EPNdB) below what is required by the International Civil Aviation Organization’s Chapter 4 standards.

Program Status/Operators

A350 airframes are assembled alongside all other Airbus widebody airframes—as well as the A320—at the company’s facilities in Toulouse. The more than 2,600 hr. of flight testing done for the A350-900 was performed by five flight-test airplanes, while the -1000’s flight-test program included three airplanes. The second A350 to fly—MSN3, registered as F-WZGG—made its first flight on Oct. 14, 2013, with the testing performed by that airframe including high-altitude testing in Cochabamba and La Paz, Bolivia, cold-weather testing in Iqaluit, Canada and hot-weather testing in Al Ain, United Arab Emirates. Subsequently, the first flights of the third and fourth flight-test airframes—MSN2 (F-WWCF) and MSN4 (F-WZNW), respectively—both took place on Feb. 26, 2014, from Toulouse, with MSN2 being the first A350-900 to have a full passenger cabin and also the airframe used to conduct the type’s early long flights. Beyond cabin-related testing, MSN2 was also used for extreme-weather testing at the McKinley Climatic Lab, located at Eglin Air Force Base in Florida. The fifth and final flight-test airframe—MSN5, registered as F-WWYB—made its first flight on June 20, 2014, with that airframe “tasked with route proving and ETOPS [extended operations] validation.” Following its certification in September 2014, the first A350-900—MSN6, registered as A7-ALA—was delivered to Qatar Airways on December 18, 2014.

In addition to the MSN059, the other A350-1000 airframes that participated in the flight-test program were MSN065 (F-WLXV) and MSN071 (F-WWXL). According to Airbus, beyond performing the variant’s first flight, MSN059 was also used for part of the airframe’s performance testing, including braking, exploration of the flight envelope, handling qualities and loads. The second -1000 variant to fly, MSN071, made its first flight on Jan. 10, 2017, with that airframe employed in a variety of performance evaluations. Among the performance testing done by MSN071 was a “flight test campaign to check aircraft and engine performance in high-altitude, warm and humid conditions,” testing that also took place at Cochabamba and La Paz, as well as Barranquilla, Columbia. That flight-test airframe also engaged in the variant’s cold-weather testing at the same location in Canada where that testing was performed for the -900. Additionally, MSN071 performed testing on the airframe’s autopilot, braking, systems and the Trent XWB powerplant. The third A350-1000 to fly, MSN065—which was rolled out in September 2016 and made its first flight on Feb. 7, 2017—was the only flight-test airframe for that variant to include a full passenger cabin, while also being used to perform early long flights, route proving, noise testing at Moron Air Force Base in Spain and hot-weather testing at Al Ain. As was the case with the -900, the first operator to take delivery of the larger A350-1000 was Qatar Airways, with the first airframe—MSN88, registered as A7-ANA—handed over on February 20, 2018.

Prior to the April 23, 2018, first flight of the A350-900ULR—a flight that was conducted by airframe MSN216, registered as F-WZNY—that airframe was rolled out of Airbus’ production facilities in Toulouse in February 2018. Subsequently, the first delivery of an A350-900ULR—MSN220, registered as 9V-SGA—to Singapore Airlines took place on September 21, 2018, with the -900ULR’s first service taking place on Oct. 11, 2018, between Singapore and New York. However, despite the fact that MSN220 was the first -900ULR to be delivered, the first revenue flight was actually operated by MSN223 (9V-SGB).

In addition to the passenger variants of the airframe, Airbus is also studying a freighter version of the A350 that would potentially be designated the A350-950F and compete with Boeing’s 777F, as well as a possible 777X-based freighter. From a size perspective, that potential A350 variant would fall between the -900 and -1000, while also featuring “a new forward fuselage plug with a cargo door and a local strengthening.”

References

  • AWIN Article Archives
  • Airbus and Rolls-Royce Commercial Materials
  • GE Aviation, Pratt & Whitney and Rolls-Royce Commercial Materials
  • EASA TCDS (A350, Trent XWB)

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