A timeline of the commercial dispute between Boeing and Bombardier:
- April 27: Chicago-based Boeing Co. asks the U.S. Department of Commerce and the U.S. International Trade Commission (ITC) to take action against Bombardier's business practices.
- May 18: The Department of Commerce confirms the beginning of an investigation. Ottawa replies by questioning a military order from Boeing for new Super Hornet jet fighters.
- June 9: ITC gives the go-ahead for Washington to continue its investigation into CSeries sales south of the border.
- June 28: The Department of Commerce agrees to delay the disclosure of its preliminary decision on possible punitive duties by two months, until Sept. 25, at Boeing's request.
- Sept. 4: Boeing International Division President Marc Allen says the U.S. giant has no intention to back down and withdraw its complaint against Bombardier.
- Sept. 5: British Prime Minister Theresa May, in a telephone conversation with U.S. President Donald Trump, pleads in favour of the Quebec manufacturer, which has more than 4,000 employees in Belfast, Northern Ireland.
- Sept. 13: Demonstrations in downtown Montreal of hundreds of union members in the aeronautics sector who denounce the Boeing approach.
- Sept. 20: Bombardier workers in Toronto walk off the job to attend a rally to support company's battle against Boeing.
- Sept. 24: JetBlue becomes latest U.S. airline to write to the ITC urging it to deny Boeing's petition, saying tariffs would harm competition and result in higher airfares.
- Sept. 26: Department of Commerce announces its preliminary countervailing duty decision on the CSeries.
