Boeing has confirmed that increasing the production of its 737 MAX aircraft is proving more difficult than expected. The company currently produces about 47 planes per month, but its chief executive, Kelly Ortberg, acknowledged during a Morgan Stanley event on September 16 that this rate is not yet stable. The main challenge lies with the production of wings at the Renton plant, near Seattle. "We are not yet stable at 47 per month. That is our goal: to achieve this stability," Ortberg said, according to Reuters. The company is still in the testing phase to ensure that this production rate can be consistently maintained. The 737 MAX is Boeing's most important commercial aircraft program, contributing significantly to the company's revenue and deliveries. After a series of quality and safety issues that affected the program, Boeing has shifted its focus from rapid production increases to ensuring the reliability and consistency of its manufacturing processes. Ortberg noted that the current bottleneck is not due to a shortage of parts from suppliers, but rather the production of wings at the Renton facility. "The area where we are currently limited is the production of wings," he explained, according to Leeham News. Despite these challenges, Boeing believes its supply chain, including the production of CFM International LEAP-1B engines, is now capable of supporting a higher production rate. Before aiming for 52 planes per month, the company must first stabilize the 47-unit production level at Renton and activate an additional 737 line at the Everett plant, north of Seattle. This new "North Line" also requires approval from the Federal Aviation Administration (FAA), which has been more involved in overseeing Boeing's operations since a panel plug detached from an Alaska Airlines 737 MAX 9 in January 2024. The FAA then limited production to 38 planes per month and required Boeing to improve its quality control systems. For airlines, the progress of the 737 MAX production is critical, as delays could affect the delivery of narrow-body aircraft needed to replace older models, expand capacity, or support new routes. Ortberg also mentioned that the certification of the 737 MAX 10, the most advanced version of the 737 MAX family, is expected to happen "very soon." Boeing has completed the necessary flight tests, and the final documentation is now being reviewed by the FAA. The certification process is a key step before the aircraft can enter service.