Not only will it float, it flies, too!

I'm amused - and interested - to read that Portuguese cork farmers are looking at using the product in aircraft manufacture.

Stubby, leafy oaks, bark carefully stripped from the trunks, line the road leading to the French-owned DynAero aircraft plant in Portugal's central-south Alentejo region -- the world's main cork growing area.

Cork trees, with bark harvested from their lower trunks (image courtesy of Wikipedia)

Plane parts designed and molded here could help shape the future of a national industry that employs some 12,000 workers, exports over 1 billion euros ($1.4 billion) a year in cork -- more than 2 percent of total exports -- and helps prevent Portugal's drying south from becoming a desert.

Portugal's annual output of 157,000 tonnes of cork is just over half of the world's total.

Cork harvest (image courtesy of Wikipedia)

DynAero's desire to build its ultralight two- and four-seat planes from cork instead of plastic seems only natural in such a place, but there is more to it than the material's abundance.

"Year after year, cork wine bottle closures are getting replaced by new materials. Producers know they have to go to more sophisticated applications," said DynAero director Philippe Sence, explaining the reasons behind the "Aerocork" project, launched last year jointly with three Portuguese firms.

Among them is the world's largest cork producer Corticeira Amorim, struggling to recover market share in the bottle stopper market, reduced to 70-75 percent from over 90 percent since the 1990s by the advance of metal screw caps and plastic closures.

. . .

Corticeira CEO Antonio Rios de Amorim said that while the fight to recover cork closures' market share against alternative stoppers was the company's top priority, research into new applications was key for future development.

"The Aerocork project is a new area of development for cork composite materials, but it uses the already successful experience in applications like kayak-building," he said.

The prototype cork plane should be ready this year.

The Aerocork partners aim to replace light porous plastic PVC with cork composite in the fuselage, wings and flaps of light aircraft, where it is coated with carbon fiber sheets.

Far from being a return to the wood-and-canvas planes from the early aviation history, the cork-carbon combination is not only light but possesses fire retardant properties. Shredded cork is already used in the thermal protection coating on the Space Shuttle's external fuel tank.

A prototype wing made of cork is laid on top of a conventional wing

In nature, the unique cellular bark protects cork oaks from frequent forest fires. Even in Australia -- one of the main promoters of screw cap use in wine -- last year's deadly fires in Victoria state have triggered a debate on replacing flammable eucalyptus plantations with cork oak.

Last year's jump in oil prices that made oil-based PVC too pricey and environmental concerns about PVC output and recycling are also among the reasons DynAero wants a new material.

"We know that after a few years PVC will no longer be used, certainly by us and most likely by others in the industry. It is a nightmare in terms of ecological aspects," Sence said. "Our idea is to sell cork-carbon parts to other firms in the future."

Cork is harvested every nine years during the oak's 200 year lifespan without damaging the trees, making the cork industry one of the world's greenest and naturally sustainable.

There's more at the link.

So, if I smell wine when next I fly, will it be from the First Class cabin, or the recycled wine corks in the fuselage?



Peter