Bombardier admits that the maiden flight of the CSeries twinjet could slip into the first quarter of next year, but the airframer is expecting to receive the wingset for its initial flying prototype within a month.
The manufacturer, which is nearing completion of its static test CSeries airframe, has been trying to keep the programme on track for first flight by the end of this year.
Bombardier recently said final assembly of the static aircraft should be "pretty much complete" by around the end of October, to be followed by assembly of FTV-1 - the designation for the first flight-test airframe.
"FTV-1 is getting its wingset in the next month," said Bombardier's senior vice-president of sales, marketing and asset management Chet Fuller, speaking at a Boyd Group summit in Dallas on 18 September.
Bombardier executives have repeatedly said the entry into service date, scheduled for the end of 2013, is more meaningful for customers.
Fuller acknowledges that the first flight "might not happen by the end of the year" and that a maiden sortie in the first quarter of 2013 could be more likely.