SINGAPORE — Bombardier and Airbus could have a final assembly line in the U.S. up and running within a year of a go-ahead, but it remains undecided whether C Series jets ordered by Delta Air Lines will be produced there or in Canada, says Colin Bole, senior vice president for commercial at Bombardier Commercial Aircraft.

While the two airframers are limited in what information they can share before Airbus’ deal to acquire a controlling stake in the C Series program wins regulatory approval, integration with Airbus is now the “top priority,” says Bole. “You can do ‘as if’ planning as long as there is nothing exchanged of a sensitive commercial nature,” Bole told Aviation Week on the sidelines of the Singapore Airshow.

The U.S. International Trade Commission recently rejected Boeing’s claim that it was harmed because Bombardier used Canadian government subsidies to sell 75 C Series passenger jets to Delta at unfairly low prices. The 4-0 ruling, which can still be appealed, negated 292% duties on the Delta jets that had been imposed by the U.S. Commerce Department. Bombardier and Delta had aimed to get around those duties by moving assembly of the jets from Mirabel, near Montreal, to an Airbus facility that assembles A320 jets in Mobile, Alabama.

Bole says it hasn’t been decided if Delta will revert to the original plan to take jets built in Canada, but confirmed that the initial delivery date of April will not be met. “When we deliver to Delta will have a significant bearing on what 2019 [output] looks like,” he says. Bombardier plans to produce 40 C Series jet in 2018.

Bole maintains ongoing talks between Boeing and Embraer about joining forces are an acknowledgement that Boeing does not have an answer to the C Series. “There’s nothing in the 737 family that properly addresses the 100-150-seat category,” he says. But he was also dismissive of the potential tie-up. “We’re skeptical as to the overall purpose, rationale, practical fit or product fit,” he says.

Meanwhile, Bole says Bombardier is increasing its focus on improving and selling its Q400 turboprop passenger aircraft. “ATR ate our lunch for a period of time, because we were not focused on [that] product,” he says. But now the Q400 line is sold out for 2018 and most of 2019.

There are no plans to upgraded Bombardier’s CRJ regional jets with new engines, as Embraer has done with its E2 family. He notes that scope clauses are keeping Embraer from selling its E175-E2 in the U.S. market. The 175-E2 "will not make it [in the U.S.] probably in my career,” he predicts.