The Airbus A350 XWB (extra wide body) aircraft is Airbus’ answer to Boeing’s 787 Dreamliner. As such, the A350 XWB takes advantage of cutting-edge carbon fibre composite construction to reduce weight (and thus burn less fuel) without sacrificing strength.
At Airbus’ North Factory in Broughton, Wales, around 650 highly-trained Airbus technicians are building wings for the A350 XWB using the latest manufacturing and production management processes.
“The facility was built specifically for the purpose of A350 XWB wing production,” explains Airbus’ Des Middleton, head of A350 Assembly in Broughton. “Station 80 is where we conduct the wing box assembly processes and Station 70 is where the wing equipping activities are carried out.”
Two factors make the North Factory noteworthy from an aerospace manufacturing point of view. For one thing, the A350 XWB wings being produced here are more than 50% made from high-strength, lightweight composite materials; an advance that required workers to be trained in this new manufacturing technique. For another, the A350 XWB’s wings “are built horizontally rather than vertically,” says Middleton. Building wings in this orientation has allowed the factory to speed up the production process.
For the record, the 46,000m2 North Factory is 23m high. This gives it a volume of 1.04 million cubic metres; the same as New York City’s Empire State Building.
The Airbus factory is a showcase for green energy technology. It has three sun-tracking solar panel arrays that generate 22,500kWH of power annually to help run the lights inside. The solar output is assisted by a wood pellet biomass boiler system: It outputs 830,000kWh annually to power more lights and heat the plant.
Meanwhile, the North Factory’s solar hot water system generates more than 30% of the factory’s required hot water (equal to 12,374kWH or heated water each year). A 100kW air source heat pump provides under floor heating.
The wing assembly process
The North Factory works around the clock making wings for the A350 XWB. At more than 30m long per side, these wings are extremely unwieldy. This is why each of the wing boxes are assembled on a special jig.
The wings are shifted inside the North Factory using slow-moving automated guided vehicles. Seeing these autonomous vehicles move wings purposefully across the factory floor, with human workers tagging alongside like dogs out for a walk, looks to a casual viewer that ‘the robots are truly in control’.
The A350 XWB wing assembly system is called a ‘pulse line’. This is because the wings travel (‘pulse’) from station to station, rather than either being assembled in a single static location or moving along on some form of conveyor belt.
“The A350 is the first program to pulse the wing assembly line,” states Middleton. “The wing box is moved by automatic guided vehicle through each step of the process: Structures to Automated Drilling, to Bolting, to removal from the jig.”
Specifically, the Airbus technicians assemble the wing’s aluminium framework (the wing box) first. The ‘wing covers’, which are produced elsewhere in the factory using carbon fibre reinforced plastic (CFRP), are then laid in place against the framework at the Structures station. The mated wing box then goes to the Automated Drilling station to have the correct assembly holes punched, and then to the Bolting station to fasten everything together.
The automated guide vehicles make it easy to safely move the large wings around the factory floor. This manufacturing efficiency reduces production time; minimizing the chance for accidents and damage during transfers.
Another North Factory efficiency is “the fully automated drilling of the top and bottom covers in Station 85,” Middleton explains. “This is the only Airbus facility that has both the conventional manufacturing process alongside an automation process.”
Once the A350 XWB wings have been assembled, the Broughton plant installs and tests electrical, hydraulic and pneumatic systems. Technicians also attach flying control systems such as ailerons, air brakes, flaps, and leading-edge slats.
Once this has been done, the wings are loaded into Airbus’ Beluga transport aircraft (expanded Airbus A300-600s) for a flight to the company’s factory in Bremen, Germany for completion. They then head to the Airbus Final Assembly Line in Toulouse, France, for mating to A350 XWB fuselages.
Challenges and improvements
Building A350 XWB wings horizontally, and using more than 50% CFRPs in them, has posed Airbus with several hurdles to clear.
“The challenges include ramp-up,” says Middleton; ensuring that the North Factory and its many suppliers keep up with Airbus’ ambitious wing assembly schedule. “We need to be able to produce wings at a rate which is in line with our delivery schedule. When you are doing this in a brand-new facility and manufacturing system, it is essential you hit the ground running and are quickly able to build wings at the required rate.
“You also have the task of ensuring operators have the right skills and competencies to build the wings. Another aspect is cost: Improving cost performance is an area of focus with all major component assembly.”
Airbus’s North Factory management is focussed on constantly making the wing production line more efficient and cost-effective.
To do this, “we currently have a number of improvement avenues, some driven from our Engineering and Design teams,” he says. “These improvements are normally driven by either ‘in-flight’ feedback from our customers, or ongoing performance improvements.
“Another improvement process is through our employees, and this is where we’ve had our major success. Over the past three-four years, our ‘Involvement improvement Scheme (Dragons’ Den)’ has proved very popular with our employees. This involves employees submitting ideas that are then investigated by a multi-functional team and, if the business case stacks up, are delivered. This scheme pays employees for their improvement ideas if the benefits are realised.”
Results to date
According to Geoff Short, head of operations in Broughton, the North Factory’s wing assembly process and improvement efforts are delivering solid results for Airbus. “In 2016-2017, we increased the build rate by 50% and halved the cost per set enabled by the Airbus operating system and continuous improvement process,” he claims. “Speaking more generally, the A350 programme is ramping up to meet customer demand: As that rate has increased, the business has reduced its build cycle and increased efficiency by reducing the build hours per set. Many improvement ideas were driven by technical process improvements, but most of the efficiency improvement ideas on the A350 came from shopfloor teams through the Dragon’s Den scheme.”
In other words, Airbus North Factory is building A350 XWB wings significantly faster than before, without compromising product quality or worker safety levels. That’s the kind of goal any aerospace manufacturer would be proud to achieve.
