Boeing 737MAX9 Door-Drop Accident and Subsequent investigations
TapTechNews August 7th news, a door-drop accident occurred on a Boeing 737MAX9 aircraft of Alaska Airlines in the US on January 5th this year, causing huge economic losses and mental trauma to the crew and passengers. For detailed content, see TapTechNews' report at that time.
Investigators from the National Transportation Safety Board (NTSB) found that the cause of this accident was that the workers in Boeing's Renton plant failed to properly install the key bolts used to secure the cabin door, resulting in damage to the aircraft fuselage during flight, and 8 people on board were slightly injured. The NTSB said that these bolts were removed to repair the rivets damaged during production and assembly, and might have been omitted after reinstalling the rivets. One worker told the investigators that they were under great pressure and had to finish the work quickly, so mistakes couldn't be avoided.
On August 6th local time, senior executives of Boeing in the US attended the hearing of the National Transportation Safety Board to provide testimony on investigations such as the in-flight door-drop accident. However, on a crucial door-unplugging and -plugging operation in the accident investigation, Boeing reiterated that there was no relevant written record and still could not determine the personnel who unplugged and plugged the door and the time when it was plugged back into the fuselage.
According to the testimony at the hearing, the fuselage of the involved aircraft was manufactured by Boeing supplier SpiritAeroSystems, and the four bolts on the latch had already been installed when it arrived at the Boeing plant. Allegedly, Boeing removed the bolts because there was a problem with the rivets next to the door latch and needed to be repaired.
The first day's hearing lasted for nearly 10 hours. Elizabeth Lund, senior vice president of quality at Boeing, said at the hearing that Boeing is making design changes and hopes to implement them within the year and then retrofit the entire fleet to prevent similar incidents in the future.
Elizabeth said in answering questions about employee isolation that two employees who might be involved in removing the bolts were placed on paid leave, and the door group manager was also on sick leave. She emphasized that Boeing's safety system only saves the video of the previous 30 days, but since the work process involved was completed in September and this accident happened in January, the video has been overwritten. In addition, a similar situation occurred with the cockpit recording of this Boeing 737MAX9 aircraft (allegedly the recording can only be saved for two hours), so the recording after the explosion has also been lost.
She also mentioned that Boeing plant has now put a prominent sign on the door latch that says Do not open and has added specific requirements for opening the door latch and procedures to ensure that the door latch will not be opened unintentionally.
This hearing should focus on those outstanding issues and the operation of Boeing before the accident, rather than the measures it took after the fact. Jennifer Homendy, chairperson of the National Transportation Safety Board, said: This is not a PR event for Boeing. What I want to know, what we want to know, is what happened (before January 5th).
Jennifer said that Boeing must take measures to improve, and the safety culture needs a lot of work. She also added that the NTSB will turn its attention to the FAA's supervision of Boeing on Wednesday.
The FAA director said in June this year that before the accident, the agency's supervision of Boeing was too lax. When talking about the FAA's sup ervision of Boeing, Jennifer said We have a lot of problems. This information is known. She cited defects, omissions and incorrect documents that have been there for years and incorrect policies.
Related reading:
The fuselage was holed during flight, and Alaska Airlines announced the grounding of 65 Boeing 737MAX9 aircraft
The US Federal Aviation Administration: Conducting an investigation into Boeing's manufacturing methods and production lines