TORONTO -- A Canadian who lost five family members in the Ethiopian Airlines crash is urging aviation authorities to conduct their own safety tests of the aircraft before letting the Boeing 737 Max 8 fly again.

Paul Njoroge, who lost his wife, mother-in-law and three children in the March 10 plane crash, was in Washington, D.C. on Wednesday for a hearing of the U.S. House Transportation Committee, which is investigating the Federal Aviation Administration’s oversight of the Boeing and its 737 Max.

“The two crashes were preventable,” he said after the hearing. “The second one should not have happened.”

During the hearing, it was revealed that safety officials estimated that 15 737 Max aircraft could crash over the next few decades if Boeing didn’t update their flight-control software, but the FAA failed to ground the plane until after the Ethiopian Airlines crash five months later.

Additional, reports showed that FAA officials knew very little about the flight-control system Boeing had implemented, which is largely to blame for the October 2018 Lion Air crash off the coast of Indonesia and the Ethiopian Airlines crash. In total, 346 people died.

For Njoroge, this is evidence that the FAA cannot be trusted for aviation safety and that all countries must do their own due diligence before letting the Max 8s back into their airspace.

“Nobody should trust the FAA,” he said. “I want these other regulators to do their own assessment of the 737 Max before it’s ungrounded, if it’s ever ungrounded. I wish it never flies again.”

Boeing hopes the 737 Max will be able to fly again early next year after it fixes the flight-control software, but the FAA has not given a timetable for approving the aircraft’s return to flight.

Njoroge said he confronted FAA administrator Stephen Dickson about why the agency failed to act once it knew the planes could be disastrous.

“It was a simple question: ‘What should you have done Mr. Dickson, after seeing that number?’” Njoroge said. “He could not answer that question. He kept beating around the bush.”

Chris Moore, a Canadian whose daughter Danielle died in the Ethiopian Airlines crash, said Wednesday’s hearing shows that the FAA is primarily focused on protecting the interests the airplane manufacturers.

“They appealed to industry, not to safety,” Moore said. “Safety was in the back seat and industry was flying that plane.”

“What we heard today was more of a: ‘We’re going to look into this, we’re going to look into that.’ Instead of oversight, it looks like they have overlook.”

Moore, who has made several trips to Washington for hearings over the past few months, said it’s important for him and his family to have a voice during the proceedings.

“My daughter didn’t die in vain,” he said. “We need to have a presence here. If nobody does, it gets swept under the rug.”

With files from CTV News' Annie Bergeron-Oliver and The Associated Press