In a recent announcement, the Federal Aviation Administration (FAA) has made it mandatory for all Boeing 737 MAX airplanes to undergo inspections for loose bolts in the rudder control systems. This requirement comes after Boeing recommended the inspections in December. The FAA has confirmed that all U.S. airlines have completed the inspections in early January and found no missing or loose rudder bolts. This mandate fulfills the U.S.’s international continued operational safety obligations.
The significance of this issue has been highlighted by the National Transportation Safety Board (NTSB) in its preliminary report on a mid-air emergency involving an Alaska Airlines Boeing 737 MAX 9. The report stated that a cabin panel was lost at 16,000 feet and suggested that four key bolts were missing from the door panel. This panel, known as a door plug, was fitted into the MAX 9 model instead of an optional exit and could have detached from the plane. The NTSB’s findings raise questions about the detection process and why the movement of the door plug on prior flights was not detected.
Boeing initially recommended the inspections after an international operator discovered a rudder bolt with a missing nut during routine maintenance. Additionally, Boeing found an undelivered aircraft with a nut that was not properly tightened. Since the recommendation was made in December, over 1,400 737 MAX airplanes have been scrutinized, with only one inspection remaining. Boeing has reassured operators that completed inspections do not need to perform additional examinations and can continue to safely fly their airplanes.
Chair of the Senate Commerce Committee, Maria Cantwell, expressed concerns about the detection process based on information received from the NTSB. She revealed that markings on the recovered 737 MAX 9 door plug indicated prior movement, raising questions about why this was not detected earlier. Cantwell’s remarks highlight the need for improved processes to ensure the safety of passengers.
Both Alaska Airlines and United Airlines reported findings of loose bolts during inspections of their MAX 9 jets last month. The FAA responded by grounding 171 MAX 9 jets on January 6, but lifted the grounding on January 24 after extensive inspections of the door plugs. As a precautionary measure, the FAA also barred Boeing from increasing the production rate of the 737 MAX until improvements in quality control are implemented.
Overall, this new requirement by the FAA for mandatory inspections of loose bolts in the Boeing 737 MAX rudder system aims to ensure the safety and reliability of these airplanes. The NTSB’s findings and concerns raised by industry experts highlight the need for continuous improvement in detecting and addressing potential issues to maintain the highest standards of aviation safety.
