Bombardier in the coming days will be taking the CSeries' carbonfibre wing demonstrator to ultimate load and the aircraft-maker is optimistic that the test results will pave the way for it to achieve further weight reductions.
"Our Belfast facility has been putting stress on it [the wing demonstrator] to collect the information", says Bombardier Commercial Aircraft president, Gary Scott.
"We have bent it to limit load and now we are continuing to bend it further until we reach ultimate load in a week or two." He says at next month's Farnborough Airshow, Bombardier will give a detailed briefing on the wing demonstrator test programme.
"It looks like we are going to be able to get to ultimate load without breaking the wing."
The carbonfibre wing already meets Bombardier's weight objectives but he adds it has been performing so well in testing, "there could be opportunities for further weight reductions".
While the carbonfibre wings are made and tested in Ireland, the CSeries aluminium-lithium fuselage demonstrator was made by Shenyang Aircraft in China and then shipped to Bombardier's Saint-Laurent plant - outside Montreal - for testing.
Scott says the aluminium-lithium test barrel "has exceeded our expectations and this allows us to make improvements to reduce the weight".
Bombardier has stated publicly that it plans to have first flight of the CSeries in 2012.
Scott says the joint-definition phase will be completed at the end of June or early July. "Some work packages have already exited the joint-definition phase because we are sort of staggering it," he adds.
After joint-definition phase there is the detailed design phase, which will make use of the test data so as to perfect the design.
Scott says the detailed design phase will be completed early next year.
"We then move into build phase for parts [although] it really starts later this year but major components [such as empennage, wings and fusealge] will only begin to come to Mirabel towards the end of 2011," says Scott referring to Bombardier's plant near Montreal where CSeries final assembly will take place.
Scott says the first part, for testing purposes, will come to Bombardier's 'complete integrated aircraft systems test area' (CIASTA) in October.