The federal government has approved design changes to the Boeing 737 Max that will allow the plane to fly again in Canada after it was banned around the world last year following two deadly crashes.

Transport Canada informed the U.S. Federal Aviation Administration on Wednesday that it has validated a series of proposed changes to the 737 Max, and expects to make a public announcement in Ottawa on Thursday.

Ottawa will require pilots to take additional simulator training on the revised 737 Max, and additional cockpit procedures will be implemented before the plane would return to service at Canada’s major airlines, said the department’s director-general of civil aviation, Nicholas Robinson.

The plane has been grounded since last March when it crashed in Ethiopia, killing 157 people, including 18 Canadians. Five months before that, 189 people were killed when another 737 Max plummeted into the sea near Indonesia.

A series of international investigations determined that both crashes were caused by software that was designed to stabilize the plane, but instead forced the 737 Max into an irreversible nosedive when fed data from a faulty sensor. Introduced by Boeing in 2016, it is now one of the deadliest commercial airliners in history.

On Wednesday, Transport Canada sent an e-mail to relatives of the 18 Canadians killed in the Ethiopian crash, informing them of the coming announcement. Several of the families had asked the government not to approve the plane unless the deadly software was stripped from the design.

“I know that the news of our completion of the validation process is not something that you wanted to receive,” said Mr. Robinson in the e-mail, which was obtained by The Globe and Mail.

“I can assure you though that our process and review to validate these changes has been comprehensive; that our decisions have been independent and driven by the analysis of our globally recognized certification experts; and, that we are confident in our validation outcome.”

The FAA cleared the revised 737 Max to fly in November, followed by regulators in Europe and Brazil. Brazilian airline Gol returned the plane to service last week, becoming the first carrier to do so. Canada’s two largest carriers Air Canada and WestJet Airlines both fly the aircraft.

However, one of the experts called to testify at Transport committee hearings into the Canadian government’s endorsement of the 737 Max said he is not convinced that the plane has been made entirely safe by the design changes.

Boeing has said the flaws in the plane’s software – known as the manoeuvring characteristics augmentation system (MCAS) – have been fixed. But Gilles Primeau, an expert in flight-control systems, said the stabilization software that caused the crashes can still, under certain conditions, be fed faulty information. He raised this flaw with Transport Canada, Boeing and the FAA, but says his concerns haven’t been addressed.

“I’d love to see proof that Boeing even noticed this condition or that the FAA’s so-called unprecedented scrutiny [of the 737 Max] noticed it either,” Mr. Primeau said. “There’s an easy way to find out: Demand to see immediately Boeing’s or FAA’s evidence that this case was studied, and how they could find a rationale to accept this.”

Under international aviation rules, the FAA scrutinizes Boeing’s aircraft designs, which are then validated by other international regulators such those in Canada and Europe.

Boeing was found to have withheld information from the FAA about the software in the original certification of the 737 Max, so that when Canadian regulators verified the plane, they were unaware that the system could force the plane into a nosedive that pilots could struggle to reverse.

The FAA was also found to have outsourced much of the scrutiny over the original design to Boeing’s own engineers in an effort to streamline the regulatory approval of the plane.

“I have completely lost confidence in them,” Mr. Primeau said of the FAA.

Transport Canada has said it is looking at changes to the way it validates new aircraft as a result of the 737 Max disasters. In addition to extra training for Canadian pilots flying the plane, new cockpit measures will be introduced, which the government plans to detail in the coming weeks.

“We will issue a Canadian Airworthiness Directive that will clearly outline the Canadian validated design changes that must be incorporated,” Mr. Robinson said in the e-mail. “In addition, we will also mandate the training requirements for air crew through an Interim Order.”

The plane will likely return to service in the new year.

“We expect these steps to take place in January, 2021,” Mr. Robinson said in the e-mail.

“In the meantime, I can assure you all that the commercial flight restrictions for the aircraft in Canadian airspace remain in effect and will not be lifted until we are fully satisfied that all its safety concerns have been addressed.”

The Globe and Mail, December 16, 2020