The Airbus A350 XWB is a family of long-range, twin-engine wide-body jet airliners developed by European aerospace manufacturer Airbus. The A350 is the first Airbus aircraft with both fuselage and wing structures made primarily of carbon fibre reinforced polymer. Its variants seat 315 to 369 passengers in typical seating layouts. The A350 is positioned to succeed the A340 and to compete with the Boeing 787 and 777.
The A350 was originally conceived in 2004 as a pairing of the A330’s fuselage with new aerodynamics features and engines. In 2006, Airbus redesigned the aircraft in response to negative feedback from several major prospective customers, producing the “A350 XWB” (eXtra Wide Body). Development costs are estimated at €11 billion (US$15 billion or £9.5 billion). As of February 2019, Airbus had received 893 orders for A350s from 51 customers worldwide. The prototype A350 first flew on 14 June 2013 from Toulouse, France. Type certification from the European Aviation Safety Agency was received in September 2014 and certification from the Federal Aviation Administration two months later. On 15 January 2015, the A350-900 entered service with its launch operator Qatar Airways, and the A350-1000 on 24 February 2018 with the same airline.
Cockpit and avionics
The revised design of the A350 XWB’s glass cockpit dropped the A380-sized display and adopted 38 cm (15 in) liquid-crystal display screens. The new six-screen configuration includes two central displays mounted one above the other (the lower one above the thrust levers) and a single (for each pilot) primary flight/navigation display, with an adjacent on-board information system screen. Airbus says the cockpit design allows for future advances in navigation technology to be placed on the displays plus gives flexibility and capacity to upload new software and to combine data from multiple sources and sensors for flight management and aircraft systems control. A head-up display is also present in the cockpit.
Avionics are a further development of the integrated modular avionics (IMA) concept found on the A380. The A350’s IMA will manage up to 40 functions (versus 23 functions for the A380) such as undercarriage, fuel, pneumatics, cabin environmental systems, and fire detection. Airbus stated that the benefits includes reduced maintenance and lower weight because as the IMA replaces multiple processors and LRUs with around 50 percent fewer standard computer modules known as line-replaceable modules. The IMA runs on a 100 Mbit/s network based on the AFDX standard, as employed in the A380, in place of the architecture used on the A330/A340.
The A350 XWB airframe is made out of 53 percent composites: carbon fibre reinforced plastic for the outer and centre wing box (covers, stringers, spars), fuselage (skin, frame, keel beam, and rear fuselage) and the empennage (horizontal and vertical tailplanes); 19 percent aluminium and aluminium–lithium alloy for ribs, floor beams, and gear bays; 14 percent titanium for landing gears, pylons, and attachments; 6 percent steel; and 8 percent miscellaneous. The A350’s competitor, the Boeing 787, is 50 percent composites, 20 percent aluminium, 15 percent titanium, 10 percent steel, and 5 percent other.
The A350 features new composite wings with a wingspan that is common to the proposed variants. Its 64.75 m (212.4 ft) wingspan stays within the same ICAO Aerodrome Reference Code E 65m limit as the A330/A340 and the Boeing 777. The A350’s wing has a 31.9° sweep angle for a Mach 0.85 cruise speed and has a maximum operating speed of Mach 0.89.
The -900 wing covers a 442 m2 (4,760 sq ft) area. This is between the 436.8 m2 (4,702 sq ft) wing of the current Boeing 777-200LR/300ER and the 466.8 m2 (5,025 sq ft) wing of the in-development Boeing 777X. However, Boeing and Airbus do not use the same measurement. The A350-1000 wing is 22.3m² (240 ft²) larger through a 30 cm (12 in) extension to the inboard sections of the fixed trailing edge.
A new trailing-edge high-lift device has been adopted with an advanced dropped-hinge flap similar to that of the Airbus A380, which permits the gap between the trailing edge and the flap to be closed with the spoiler. It is a limited morphing wing with adaptive features for continuously optimising the wing loading to reduce fuel burn: variable camber for longitudinal load control where inboard & outboard flaps deflect together and differential flaps setting for lateral load control where inboard & outboard flaps deflect differentially.
The manufacturer has extensively used computational fluid dynamics and also carried out more than 4,000 hours of low- and high-speed windtunnel testing to refine the aerodynamic design. The final configuration of wing and winglet was achieved for the “Maturity Gate 5” on 17 December 2008. The wingtip device curves upwards over the final 4.4 m (14 ft).
The wings are produced in the new £400M, 46,000 m2 (500,000 sq ft) North Factory at Airbus Broughton, employing 650 workers, in a specialist facility constructed with £29M of support from the Welsh Government.
The A350-1000 is the largest variant of the A350 family at just under 74 metres in length. It seats 366 passengers in a typical three-class layout with a range of 8,000 nmi (14,800 km). With a 9-abreast configuration, it is designed to replace the A340-600 and compete with the Boeing 777-300ER and 777-9. Airbus estimates a 366-seat -1000 should have a 35 t lighter operating empty weight than a 398-seat 777-9, a 15% lower trip cost, a 7% lower seat cost, and a 400 nmi (740 km) greater range. Compared to a Boeing 777-300ER with 360 seats, Airbus claims a 25% fuel burn per seat advantage for an A350-1000 with 369 seats. The 7 m (23 ft) extension seats 40 more passengers with 40% more premium area. The -1000 can match the 40 more seats of the 777-9 by going 10-abreast but with diminished comfort.
The A350-1000 has an 11-frame stretch over the −900 and a slightly larger wing than the −800/900 models with trailing-edge extension increasing its area by 4%. This will extend the high-lift devices and the ailerons, making the chord bigger by around 400 mm, optimising flap lift performance as well as cruise performance. The main landing gear is a 6-wheel bogie instead of a 4-wheel bogie, put in a one frame longer bay. The Rolls-Royce Trent XWB engine’s thrust is augmented to 97,000 lbf (430 kN). These and other engineering upgrades are necessary so that the −1000 model maintains range.
In 2011, Airbus redesigned the A350-1000 with higher weights and a more powerful engine variant for more range for trans-Pacific operations which will boost its appeal to Cathay Pacific and Singapore Airlines, which committed to 20 777-9, and United Airlines, which could turn to 777-300ERs to replace its 747-400s. Emirates was disappointed with the changes and cancelled its order for 50 A350-900s and 20 A350-1000s instead of changing the whole order to the larger variant.
Assembly of the first fuselage major components started in September 2015. In February 2016, final assembly started at the A350 Final Assembly Line in Toulouse. Three flight test aircraft was planned with entry into service scheduled for mid-2017. The first aircraft completed its body join on 15 April 2016. Its maiden flight took place on 24 November 2016.
The A350-1000 flight-test programme planned for 1,600 flight hours; 600 hours on the first aircraft, MSN59, for the flight envelope, systems and powerplant checks; 500 hours on MSN71 for cold and warm campaigns, landing gear checks and high-altitude tests; and 500 hours on MSN65 for route proving and ETOPS assessment, with an interior layout for cabin development and certification. In cruise at Mach 0.854 (912 km/h; 492 kn) and 35,000 ft, its fuel flow at 259 t (571,000 lb) is 6.8 t (15,000 lb) per hour within a 10,000 km (5,400 nm), 11 h 30 m early long test flight. Flight tests allowed raising the Maximum Take-Off Weight from 308 to 316 t (679,000 to 697,000 lb), the 8 t (18,000 lb) increase giving 450 nmi (830 km) more range. Airbus then completed functional and reliability testing.
Type Certification was awarded by EASA on 21 November 2017, along FAA certification. The first serial unit was on the final assembly line in early December. After its maiden flight on 7 December, delivery to launch customer Qatar Airways slipped to early 2018. The delay was due to issues with the business class seat installation. It was delivered on 20 February and entered commercial service on Qatar Airways’ Doha to London Heathrow route on 24 February.
It features an automatic emergency descent function to around 10,000 ft (3,000 m) and notifies air traffic control if the crew fails to respond to an alert, indicating possible incapacitation from depressurisation. The avionics software adaptation is activated by a push and pull button to avoid mistakes and could be retrofitted in the smaller -900. All performance targets have been met or exceeded and it remains within its weight specification, unlike early −900s. Its basic 308 t (679,000 lb) maximum take-off weight was bumped to 311 t (686,000 lb) before offering a possible 316 t (697,000 lb) version. Its 316 t MTOW appeared in the 29 May 2018 update of its type certificate data sheet. This raised its range from 7,950 to 8,400 nmi (14,720 to 15,560 km). A further MTOW increase by 3 t to 319 t is under study to be available from 2020 and could be a response to Qantas’ Project Sunrise.