OTTAWA—Transport Minister Marc Garneau says Boeing 737 Max jets will remain grounded for “as long as it takes” after revelations that the pilots of an Ethiopian Airlines’ flight — caught in a tug-of-war with an automated system — followed emergency procedures but were unable to stop the aircraft from nosediving into the ground.
Ethiopian aviation officials on Thursday released the early results of the investigation into the Mar. 10 crash of a nearly new Ethiopian Airlines’ Boeing 737 Max that killed 157 passengers and crew, including 18 Canadians.
The report reveals that the Ethiopian pilots faced the same flight control problems as the crew of a Lion Air Boeing 737 Max less than five months earlier, with the same deadly results.
Yet the report highlights a troubling twist — the crew of the Ethiopian flight appeared to follow emergency procedures to disable an automated system that was pushing the jet’s nose downward.
Those emergency procedures had been highlighted to pilots in the wake of the Lion Air accident. However, for the Ethiopian Airlines’ crew, they apparently were not enough to prevent a crash.
“We want to analyze it to find out what interaction there was from the pilots with that equipment and to see if they followed those steps,” he told reporters on Parliament Hill.
“This is very important to see, to confirm whether or not those steps were followed, and if they were followed what didn’t work. That’s the question,” he said.
In the wake of the two accidents, regulators around the globe, including Transport Canada, grounded the jets last month. In Canada, WestJet, Air Canada and Sunwing together have 41 of the model and dozens more on order.
The two crashes have raised questions about regulatory oversight over the certification of new or updated aircraft and the interaction between pilots and automated systems.
Attention in both accidents has focused on the jet’s “manoeuvring characteristics augmentation system,” or MCAS. If it detected there was a risk of an aerodynamic stall, when the wings lose the airflow needed to create lift, it would automatically pitch the nose down.
In both accidents, it appears that a faulty sensor fed erroneous data to the system, prompting it to pitch the nose down even though there was no risk of a stall. That left the pilots of both planes in a wrestling match with the system, pulling back on the control columns in a futile effort to arrest the descent.
The Ethiopian pilots were quick to identify the emergency procedure to disable the system, according to the preliminary report, but were unable to move the stabilizer manually. The jet crashed barely six minutes after takeoff from Addis Ababa.
Ethiopian Airlines said its pilots followed Boeing’s recommended procedures “to handle the most difficult emergency situation.”
“Despite their hard work and full compliance with the emergency procedures, it was very unfortunate that they could not recover the airplane from the persistence of nose diving,” the airline said in a statement.
In their preliminary report, Ethiopian aviation authorities recommended that Boeing review the flight control system and said regulators should verify that review before allowing the Boeing 737 Max fleet to resume flights.
Boeing has been scrambling to respond to both accidents and recently unveiled changes to fix problems with the automated system. They include redundant air sensors that provide data to MCAS and new flight deck displays to alert pilots to problems. Software changes will limit the authority of the system, ensuring it does not exceed the ability of the pilots to counteract it.
“This update, along with the associated training and additional educational materials that pilots want in the wake of these accidents, will eliminate the possibility of unintended MCAS activation and prevent an MCAS-related accident from ever happening again,” Boeing CEO Dennis Muilenburg said in a statement Thursday.
Boeing hopes to implement those changes in the coming weeks. Garneau said that it will be up to U.S. Federal Aviation Administration to certify that fix but said that Canada will make its own “independent” decision.
“I can assure Canadians that the 737 Max 8 is not going to be allowed to fly until we are totally satisfied that it is a safe plane to fly,” he said.
Asked how long that might be, Garneau responded, “As long as it takes.”
He said the planes will only be cleared when “everybody is satisfied … we understand what happened and we found a solution that is 100 per cent reliable.”
Bruce Campion-Smith is an Ottawa-based reporter covering national politics. Follow him on Twitter: @yowflier