Boeing Co.’s quality control monitors must turn solidly green before US aviation safety regulators will be convinced the planemaker can support higher production rates and exit output limits imposed on its 737 Max jetliner.

“We have made it very clear that those metrics need to be in the green before the production increases above a certain level,” Mike Whitaker, the US Federal Aviation Administration’s top official, said in an interview in Washington on Tuesday. “That’s going to be our focus over the next couple of months to get clarity around that.”

The FAA capped output of Boeing’s 737 Max at a rate of 38 per month in the wake of a January near-catastrophe, in which a door cover blew off during flight. The accident triggered a series of revelations of manufacturing lapses inside Boeing’s factories and forced the company to curtail production as it gets its processes back on track.

The action plan that Boeing crafted in response to the crisis gave the FAA access to key performance indicators, monitored on traffic lights, that provide a real-time glimpse into the flow of work in its Renton factory and across the supply chain. The US planemaker has struggled with out-of-sequence manufacturing that leads to quality breakdowns, as it retrains a workforce heavy on new hires and grapples with parts shortages lingering from the Covid pandemic.

Boeing is eager to raise output again because the 737 Max represents its biggest cash cow. The company delivered 32 of the single-aisle aircraft in August, bringing handovers of the plane this year to 201 units, down from 271 through the same period a year ago.

The agency has also stepped up its oversight of the planemaker with additional inspectors in its factories and regular meetings as the company carries out a comprehensive plan to address production breakdowns. Whitaker didn’t say when Boeing might be released from its imposed production cap.

As part of Boeing’s overhaul, the company switched senior management, including the appointment of Kelly Ortberg as new chief executive officer to succeed Dave Calhoun. Whitaker said he plans to meet in person at least once a quarter with Ortberg and speak by phone as needed.

Whitaker said the two have spoken to “a couple of times” and that Ortberg is aware of “what our expectations are and that we’re going to continue to have the intensive level of engagement that we’ve had.”