Ahead of a 2016 meeting to discuss training requirements for the 737 MAX, a Boeing employee infamously described clueless federal regulators as “dogs watching TV.” After two deadly crashes that claimed 346 lives and a congressional investigation that blasted “grossly insufficient oversight,” these dogs may have finally found their bite.

The Federal Aviation Administration recently denied Boeing permission to move ahead with a key step in the certification process for its new 777X widebody twin-engine jet, citing a litany of concerns, including a serious flight-control incident in December 2020.

In a scathing letter first reported by Seattle Times aerospace reporter Dominic Gates, the agency listed almost a dozen issues with the airplane, which began its test-flight program last year.

“The technical data required for type certification has not reached a point where it appears the aircraft type design is mature and can be expected to meet the applicable regulations,” wrote Ian Won, acting manager for safety at the FAA’s Boeing oversight office.

In short: “The aircraft is not yet ready.”

The move will likely delay the jet’s use in commercial service into early 2024, four years past its initial target. This is bad news for a struggling Boeing in the short term, but a welcome sign the FAA may no longer have a rubber-stamp relationship with the aerospace company.

Late last year, Congress passed legislation that restored stricter oversight by the FAA and in May, a congressional committee requested records to investigate lapses in production quality on the 787 Dreamliner, the 737 MAX and the 767-based KC-46 tanker. Also in May, the FAA fined Boeing $17 million over 737 production errors.

During the 737 MAX certification process, Boeing misled compliant regulators who had delegated increasing authority to the manufacturer in determining the safety of its own planes. It turned out to be misplaced trust in a company that had left its tradition of engineering rigor behind in a rush to feed the bottom line.

The return of real government oversight is a critical step not only to rehabilitate the FAA’s reputation at home and around the world, but also help restore the credibility and standing of America’s largest manufacturing exporter.

The work of rebuilding that trust and changing the corporate culture that allowed it to erode won’t happen overnight. Won’s letter points out that Boeing has been pushing for months to continue certification even while the FAA questioned the new jet’s readiness.

For its part, Boeing said it “remains fully focused on safety as our highest priority throughout 777X development.”

That’s good. But whether the company has learned its lesson, thanks to federal regulators finally doing their job, no one has to take Boeing’s word for it.