New composite wing reduces drag

Right now, preparations are being made ahead of the manufacture of Saab's most complex composite article to date. A wing shell where the parts are integrated into a single co-cured item. The laminar flow will reduce drag and thereby lower fuel consumption and emissions.

Pontus Kallén, COO Aeronautics, inspects the new test panel.

As part of its role within Clean Sky SFWA (Smart Fixed Wing Aircraft), Saab will develop and produce an upper wing shell which, together with parts from other partners will form an entire outer wing. This outer wing will be test flown on an Airbus A340-300 in 2014 to verify the laminar flow that reduces drag, thereby lowering fuel consumption and emissions. The wing concept is expected to form a key component of Airbus' future Single Aisle family.

One step is now ready in the preparations ahead of the production planned for 2012. A test panel has been built to test the design and tooling concept and to ensure that the item meets the strict demands on surface quality.

Jonas Bohlin, sub-project manager at Saab within CleanSky SFWA, describes the test panel:

"It is a 2 metre by 2 metre wing shell. The leading edge, stringers, front spar mounting and rib fastenings are integrated into a single item, and to avoid the fasteners piercing through the shell, the entire item is cured simultaneously. This is a highly advanced composite article and is also the first piece of hardware we are producing within Clean Sky SFWA."

The newly produced test panel weighs barely 100 kg. The material is the same carbon-fibre pre-preg that is being used in the Airbus A350, and is the latest available on the market. The Alcas project, combined with experiences that have been built up over the past ten years, have provided much of the basis for the wing shell's development.