(Washington Comprehensive) According to the preliminary investigation report of the US transportation, the sealing door of the Alaska Aviation Boeing 737 MAX 9 passenger aircraft falls off before the flight, and the four bolts required for the fixed cabin door are no longer visible.
The National Transport Safety Commission issued a preliminary investigation report on Tuesday (February 6) stating that there was no damage or deformation around the hole where the four bolts were located, which proved that the bolt was lost before the sealing door was falling off.According to evidences such as collected photos, Boeing's assembly plant in Renton, Washington has demolished these bolts due to work needs, but did not load it back.
The report said that on August 31 last year, the aircraft fuselage arrived at the Renon assembly plant and received the inspection before delivery.The next day, in order to replace the five damaged rivets on the side of the incident door, the cocktail door was removed and four bolts used to fix it.However, the photos taken after replacement show that at least three bolts are not reinstalled.
The National Transportation Safety Commission is still investigating the matter to determine which steps of the workers' opening and closing the door are authorized.Analysts said that it is necessary to clarify why the factory has not been checked again after the factory completes the demolition and reinstallation work to ensure that the bolt is installed in place; from this report, it can be seen that the internal quality management system inside the Boeing company has a deviation.
Boeing's MAX series aircraft constantly emerge in various problems.The company has recently disclosed that about 50 unprepared 737 aircraft have rivet hole manufacturing defects.Boeing said that he would continue to cooperate with the investigation, and CEO Karkhorn said: "No matter what conclusions are finally concluded, Boeing must be responsible for everything that happened. We are implementing a comprehensive plan to improve quality and enhance the stakeholders' related parties.Confidence.
At the parliamentary hearing on Tuesday, the Federal Aviation Administration Director Whitack said that after the incident of Alaska Airlines, it is necessary to strengthen the supervision of Boeing and truly solve the problems left over in the past.
