Australian made

“We began by understanding the overall shape of the wingtip fence which is determined by aerodynamics and the 80m box shape of the aircraft, and we were given a number of criteria such as the noise criteria for London Heathrow for example, so the wingtips and fences play a critical part in meeting those requirements, and obviously the overall aircraft performance – so all that worked into the actual shape of the wingtip and fence. ” “The primary structure of the wing is what you need to interface with, and that primary structure is a given, so we’ve got to attach to that structure in the most efficient way,” Cale added. “That determined the structure of the wingtip box, and then the structure in the fence assemblies was driven by aerodynamic loads. The other major design consideration was metal versus composite, and the big driver there was the repairability is much easier with metals.

We had a very aggressive weight target, and we were able to provide very close on the same weight for both solutions, so the repairability and costs were the main drivers. The other part of metal versus composite – the metal conducts lightning very easily so you don’t have hot spots which you do with composites, so that also drove us towards the metal design. They’re all aluminium alloys. ” In very general terms, the wing fence artificially increases the aspect ratio of the wing, making it more efficient for long range missions. “The A380 wingspan fits into the 80m by 80m box by just 20cm,” said Cale. “So if you wanted the efficiency we have now, we couldn’t have increased the span – the span would have to be more than the height of the fence to get the same efficiency. ” “The aerodynamic effect is to reduce the size of the wingtip vortices, to reduce the drag,” added Michael Baker, lead manufacturing engineer. “It acts as a wall between the low pressure and the high pressure – smaller vortices equals less drag equals more range. ” While the A380’s wing fence design is outwardly similar to that used on the much smaller A320, it is in fact very different.

“When they scaled the A320 fence up to the A380 originally, the aerodynamicists fiddled with it a bit and took some of the more peculiar features out,” Cale continued.

“If you look at an A320 fence it’s actually very flat, but on the A380 they turned it into an aerofoil shape. And if you look at our design and what’s involved in the manufacturing, it’s a very sophisticated design.

Because of the amount of effort we went to take weight out, it’s more on the level of a high performance military aircraft. ” Wingtips are sent to the Airbus UK wing manufacturing facility in Broughton where they are mated with the main wing box structure, while the wing fences are added to the aircraft on the A380 Final Assembly Line in Toulouse. “A shipset weighs about 340kg, so that’s 170kg per side,” said Baker. “They leave here in a standard grey colour – the fences get painted in customer colours at Toulouse, but the wingtips usually stay grey. Although we get an MSN number on each shipset and we do have an idea of who the customer is, that might change. But we remember building Qantas’s first wingtip – MSN013 – in late 2004 and early 2005. ”

“The first contracted run is for around 100 shipsets, and we’re increasing our rate. ”