The Federal Aviation Administration on Wednesday provided a pathway for Boeing to resume 737 MAX 9 flights.

Why it matters: Following the announcement, both United and Alaska airlines revealed plans to resume flying their grounded 737 Max 9 aircraft after receiving final approval from the agency to complete the process to return the aircrafts to service.

Driving the news: The FAA laid out an inspection and maintenance process that the company must carry out on each of its grounded 171 Boeing 737-9 MAX aircrafts to make them eligible to return to service.

• The agency also informed Boeing that it will not grant any production expansion of the MAX, including the 737-9 MAX.
• "The Jan. 5 Boeing 737-9 MAX incident must never happen again," the FAA said in a statement.

We grounded the Boeing 737-9 MAX and made clear it would not return to flight until it was safe. The enhanced review our team completed gives me and the FAA confidence to proceed to the inspection and maintenance phase prior to returning to operation. https://t.co/xcC5CjdU6p

— FAA Mike Whitaker (@FAA_Mike) January 24, 2024

State of play: The roadmap comes after an Alaska Airlines Boeing 737 Max 9 plane lost its exit door plug during a flight earlier this month that prompted the launch of a federal investigation in addition to the aircrafts' grounding in U.S. territory.

• The incident aboard Flight 1282 has also resulted in a multi-passenger lawsuit and raised further questions about the aircraft's safety.
• Following the grounding, both Alaska and United airlines said they found problems with loose hardware.
• Before the mid-flight incident, Boeing advised airlines in December to conduct checks on its 737 Max jets after an airline had discovered a "bolt with a missing nut."

What's next: United Airlines said in a letter to employees that it hopes to resume flying the grounded planes on Sunday.

• Alaska Airlines announced in a statement that it expects to bring the first of its grounded planes "back into scheduled commercial service on Friday."

Of note: The CEOs of both United and Alaska airlines have expressed frustrations with Boeing in the wake of the mid-flight incident.

What they're saying: "The exhaustive, enhanced review our team completed after several weeks of information gathering gives me and the FAA confidence to proceed to the inspection and maintenance phase," FAA Administrator Mike Whitaker said in a statement.

• "However, let me be clear: This won't be back to business as usual for Boeing," he added.
• "We will not agree to any request from Boeing for an expansion in production or approve additional production lines for the 737 MAX until we are satisfied that the quality control issues uncovered during this process are resolved."

Meanwhile, Boeing said in a statement the company "will continue to cooperate fully and transparently with the FAA and follow their direction as we take action to strengthen safety and quality at Boeing."

• It added it would also "work closely with our airline customers as they complete the required inspection procedures to safely return their 737-9 airplanes to service."

Between the lines: Boeing wants to scale up MAX 9 production to better compete with Airbus, which has been outperforming Boeing even before all this, per Axios' Alex Fitzpatrick.

• Plus, the airlines are all hungry for more planes given the travel demand.

Go deeper: Why Boeing and Airbus dominate the commercial jet industry

Editor's note: This article has been updated with comment from Boeing and Alaska Airlines.