OTTAWA - Internal government documents about the Boeing 737 Max are raising new questions about Canada's aircraft approval process.
The documents, made public at a parliamentary hearing Thursday, reveal that Transport Canada test pilots voiced concerns about a key flight-control system going back more than three years before system flaws led to worldwide grounding of the plane.
The department's queries about the Max jet's anti-stall system emerged in a 2016 debriefing, but direct answers were never provided by Boeing Co. or the U.S. Federal Aviation Administration, resulting in certification the next year despite the questions remaining "open."
The plane's MCAS software, which automatically pushes the nose of the aircraft down in certain circumstances, has identified as a key factor in two crashes in Indonesia and Ethiopia that killed all 346 people on board, including 18 Canadians, and triggered a grounding of the jet in March 2019.
Several weeks after the first crash in October 2018, Transport Canada again pushed Boeing for more information about a potential defect that could have "catastrophic" consequences, but allowed the aircraft to keep flying.
Under a longstanding bilateral agreement, Cancada outsources much of its aircraft review process to the U.S. regulator, which in turn had passed on part of its oversight to Boeing itself.
On Thursday, Conservative MP Todd Doherty asked Transport Minister Marc Garneau at the federal transport committee hearing why the plane was certified given the concerns. In a heated exchange, Garneau said the issues raised by Transport Canada simply amounted to questions, and that Doherty failed understand the approval system.
Canadian regulators now plan to conduct their own review of changes Boeing is making to the anti-stall system.