Europe’s air-safety regulator pledged to scrutinize future U.S. jet designs more closely and place greater emphasis on human factors as it prepares to approve the return of Boeing’s 737 MAX after two fatal crashes.

The European Union Aviation Safety Agency (EASA) will take a more active role in certification of U.S. models, previously entrusted largely to the Federal Aviation Administration (FAA) under a bilateral agreement, Executive Director Patrick Ky told the European Parliament on Monday. The change will also apply to planes developed in Canada and Brazil.

“The direction which had been taken was to reduce more and more the level of involvement of EASA on FAA-approved projects,” he said. “We have stopped this trend and we will increase our level of involvement, our level of independent review of U.S. projects, in order to build our own safety assessments.”

Ky reiterated that he’s confident the MAX is safe to fly after EASA conducted multiple tests on the jet that showed Boeing had met recertification conditions. The collapse in travel demand triggered by the COVID-19 crisis means airlines should have time to ensure adequate training on modified systems, he said.

Airlines in Europe will be able to begin operating the MAX as early as this week, after EASA signs off on the final airworthiness directive. Gaining the European agency’s blessing will help build global support for the revamped jet after the crashes triggered a global grounding in March 2019. Among major regulators, the U.S., Canada and Brazil have already signed off on the changes.

Ky also said that EASA is looking at comments from Ed Pierson, a former production supervisor at Boeing’s 737 plant near Seattle, who alleged that there are still issues with the MAX even as it resumes operations.

“Many important questions still remain unanswered,” Pierson wrote in a report on his personal website. Models including the MAX and the 737-based P-8 Poseidon military plane may still have defective angle-of-attack sensors and electrical-system problems that could cause another tragedy, he said.