A new £400m plant making carbon-fibre wings for Airbus's new A350 airliner will secure 6,000 jobs in Flintshire, the company says.
About 650 workers will be based at the North Factory, in Broughton, where the wings will be made.
Airbus says it means job security for all 6,000 staff at Broughton, the UK's largest single manufacturing site.
It has more than 550 orders for the A350, due to be in service in 2013 and able to carry up to 340 passengers.
More than half of the wings' make-up will be carbon fibre, which, says Airbus, will make the A350 25% more fuel efficient than current airliners of the same size.
Carbon fibre is already used in some wings but these will be the first where more than 50% features the new material.
The new, 46,000 sq metre factory will be Broughton's largest development since the opening of the West Factory in 2003, which makes wings for the Airbus A380 superjumbo.
Paul McKinlay, head of the north Wales site, said: "Broughton has got an extremely proud history, 70 years of aviation history.
"It's great we are staying ahead of the technology with state-of-the-art materials and state-of-the-art manufacturing processes. I'm delighted that Broughton is part of that.
"For our employees, this new factory - this aircraft - signals security of employment for the coming years at Broughton, and with 6,000 employees here that's absolutely great news."
Mark Barclay, Airbus's head of wings manufacture, told BBC Wales: "We have an order backlog of five or six years, but again you can never say [jobs are] secure forever - given the market downturns, given some of the announcements that could happen in terms of fuel pricing or global recessions.
"But for the time being we have a very healthy order book and I'm counting on all of the good people of Broughton and indeed the UK and their supply chain to step up to the mark here."
Mr Barclay said support from the Welsh Government had been "first class".
It has invested nearly £29m towards composite wing training and advanced manufacturing at Broughton.
First Minister Carwyn Jones said: "This is a fantastic day for both Airbus and Wales.
"The wings being made here showcase us at our best - a world class company based here in Wales making a product that will be used across the globe.
"The Welsh Government has a very close and highly valued working relationship with Airbus which is an important company for the country.
"We have invested £29m to ensure that the North Factory was opened here in Wales and that the new, significantly lighter A350 wings could be assembled at this site."
Llyr Huws Gruffydd, Plaid Cymru's North Wales AM, said: "At a time when jobs are very hard to come by, news that highly skilled work will be available at this new plant in the north is a huge vote of confidence in the local workforce."
The A350 will be up against the Boeing Dreamliner 787, which was originally scheduled for delivery in 2008 but was delayed.
Boeing has 821 orders for the 787, which it says is 20% more fuel efficient.