The problem that caused a door plug to blow off a Boeing 737 Max 9 plane during an Alaska Airlines flight last month could happen again, according to National Transportation Safety Board chair Jennifer Homendy, who added to recent criticism of Boeing by claiming the airplane manufacturer has a “quality control problem.”KEY FACTS

Homendy told CNN an incident like the door plug blowout “can happen again,” adding the agency exists to “ensure this never happens again.”

There is “no way” the plane should have been delivered to Alaska Airlines, Homendy said, after a preliminary report released Tuesday by the agency determined the Boeing plane was missing four bolts that attach the door plug to the plane’s fuselage.