BROUGHTON — While it’s not yet possible to climb inside the wing of Airbus’ newest jetliner, I want to take you inside the aerodynamic backbone of the A350 XWB. In Broughton, UK about 25 miles southwest of Manchester, Airbus is rapidly expanding its wing factory to include build-up operations for its long-range composite twin. The airframer already assembles wings for the A320 and A330/A340, as well as the A380.
The A350 is the second (largely) composite wing to be built by Airbus and the first for it commercial product line. The first is the A400M which is currently in flight testing. The wing is generally made up of three major components: The top and bottom wing skins, the front and rear wing spars, made from composite, and the inter-spar ribs which are aluminum lithium. Once mated to the center wing box and winglets attached, Airbus’s new jetliner will sport a wingspan of 212ft 5.2in (64.75m).
Currently, Airbus is in the process of assembling a half-span wing box demonstrator to test manufacturing techniques, including automated drilling of the top and bottom wing skins. The “lessons learned” on the 55ft 9in (17m) test wing box will be fed back into the detailed design and manufacturing plan for the program. The demonstration box is instrumented with strain gauges to measure the changing loads on the wing during manufacturing.
Because the wing is made up of both composite and aluminum, the different materials have different coefficients of expansion, meaning that each material will expand and contract differently at a given temperature. This requires the wing design to take into account the changing shape of the varied materials. During manufacturing the jig beds that hold the wingbox are on slides that expand and contract. During the winter, Airbus heated the test facility and then let it cool to see how the wing structure would react.
Both the front spar and fixed leading edge will be manufactured by Spirit Aeroystems in Kinston, North Carolina and Prestwick, UK, respectively. The rear spar will be manufactured by GKN in Filton, UK, while the upper and lower wing covers will be fabricated in Stade, Germany and Ilescas, Spain, respectively.
The forward and rear spars arrive in Broughton as three pieces: an inner, mid and outer. Build up of the three modules will see the front and rear spars joined to the aluminum lithium ribs. The new process is intended to save cycle time by loading each complete module into the assembly jig before joining them together, rather than doing a complete build up of a full forward and rear spar in the main area.
Once placed into the jigs, the covers will be installed on the spars and ribs. At first, the covers will be tacked, not bolted on, then moved by an automatically guided vehicle (AGV) into the drilling cell. A gantry-like system will drill the top cover and a “cartesian-like” machine will drill the lower cover. Because it is made up of a single piece cover, only 5,000 holes are drilled, compared to the much larger aluminum A380 wing requiring 750,000. The main driver for this reduction comes from the bonded, not bolted, stringers on the top and bottom skins.
For the first time on its commercial programs, Airbus will shift from a vertical wing build up to horizontal. The main driver was the ability to access the wing box once both one-piece wing covers are installed. With 19.7ft (6m) between the front and rear spar, Airbus opted to turn the wing horizontal to minimize the potential damage from falling tools, and more importantly make the underwing access holes easier to get to.
The wing will be moved again by AGV to a bolting station where the previously tacked covers will be removed, deburred, sealed then fastened to the structure. Following this stage, the wing will move again to a equipping station that is shared with the A330, where the fuel system and limited hydraulics will be installed. Each set of wings will then go on to painting, followed by loading onto the Beluga for shipping to Bremen, German for complete outfitting of the electrics, pneumatics, remaining hydraulics, external systems and control surfaces before making the trip to final assembly in Toulouse.
This post was originally published to the internet between 2007 and 2012. Links, images, and embedded media from that era may no longer function as intended.
This post originally appeared at Flightglobal.com from 2007 to 2012.