The National Transportation Safety Board (NTSB) revealed that Alaska Airlines allowed a Boeing plane to continue flying despite warnings from a cabin pressurization system. The NTSB reported that brand-new Boeing 737 Max 9 had three instances of warning lights being triggered on previous flights, with two occurrences happening on consecutive days before the aircraft experienced a fuselage blowout on its flight on Friday.
Even though the warnings prompted the company to cease flying the aircraft over the Pacific Ocean to Hawaii, they still allowed it to operate over land, according to the NTSB. The incident occurred when a plug covering a spot left for an emergency door tore off the plane as it flew over Oregon at an altitude of 16,000 feet.
Alaska Airlines cleared the plane for flight after maintenance crews inspected it, but the airline decided to avoid using it for the long route to Hawaii over water, concerned that the warning light might reappear and require a swift return to an airport. The flight on Friday was headed from Oregon to Southern California and managed to make a safe emergency landing back in Portland without any serious injuries to the 171 passengers and six crew members.
Following the mid-air incident, United Airlines and Alaska Airlines discovered loose parts on multiple grounded Boeing 737 Max 9 aircraft, raising significant concerns about the manufacturing process for these passenger planes. The Federal Aviation Administration (FAA), which oversees the industry in the United States, grounded 171 Max 9 planes worldwide after the incident. United Airlines found bolts needing additional tightening, while Alaska discovered some loose hardware during its fleet checks.
United operates 79 Max 9 planes, the most substantial fleet of this aircraft, while Alaska has 65, with the remainder being operated by other international airlines. The incident has raised concerns about the production process and quality control for the Max 9, a model that has been under scrutiny since the global grounding of the 737 Max family of aircraft in March 2019 after two crashes that claimed 346 lives.
The FAA approved a road map for carriers to complete enhanced inspections of both left and right door plugs, components, and fasteners to ensure the safety of the aircraft before they can resume operations. Boeing has pledged to work closely with Max 9 operators to address any findings during the latest inspections and uphold the highest safety and quality standards for its airplanes.