Ten days after an Alaska Airlines 737 MAX 9 have a door blown out on Flight 1282, FAA, NTSB and Boeing are still trying to understand what happened wrong.
On January 14, 188 aircraft from 216 delivered remained grounded, most of it belonging to Alaska, United Airlines, Aeromexico and Copa Airlines.
The incident, which took place on January 5 during a flight that departed from Portland, ended up without injured, but Boeing’s reputation, which had not yet recovered from several previous problems, was again the target of scrutiny by governments, companies, investors and passengers.
The door plug, a piece measuring 26 by 48 inches that has a window in the center, is a solution used by Boeing when the 737 Max 9 customer does not use a high density configuration.
In this situation, the two emergency doors behind the wings can be replaced by the piece, which fits the same space, but is secure by a bolt mechanism and articulated at the bottom.
For passengers, there is no difference except for the largest space between the windows as the internal finish covers the joints. The solution has been applied since the 737-900 of the previous NG series, and there have never been reports of problems.
But for experts consulted by The Seattle Times, the incident with the 737 Max 9 registration N704al may have been caused by the absence of bolts that lock the door plug.
The metal piece was found in the backyard of a house in Portland and was practically intact. According to an initial report from NTSB, US transport security agency, so far no of the bolts have been found.
The door plug was sent to the NTSB laboratory in Washington, which will examine the piece and determine if they were actually installed on the assembly line.
Spirit Aerosystems under pressure again
Despite the door plug appears to be a makeshift solution to avoid costs of producing a different fuselage, the safety mechanism was considered quite appropriate to cover the emergency exit space.
The piece is fitted so that 12 metal brackets align with another 12 stop pads and the pressurization of the cabin does the rest of the work.
For the piece to be triggered, however, it is necessary to move the plug up, which is then folded down and held by the two joints installed at the height of the cabin floor.
What is discussed is precisely how the play moved without being noticed since just a bolts just to hold the plug in place. The hypothesis raised by the outlet is that the plug has slowly moved to each takeoff and landing cycle, which would reinforce the alternative that there were no installed pieces.
The 737 MAX fuselage and other Boeing aircraft is manufactured by Spirit Aerosystems, a supplier that has been a division of Boeing and still maintains great ties with the manufacturer.
The installation of the door plug is the attribution of Spirit, but what amazes observers is how Boeing would not have checked the work when the fuselage was sent to Renton, where is the final assembly line of the 737 Max.
In recent months, aircraft production has been interrupted several times after assembly processes had problems that even included holes of misaligned rivets and larger holes than projected.
But despite Spirit possibly wrong in assembling the door plug, for many critics Boeing would be true to blame, after all the 737 MAX is the product of the planemaker.
Probably, the explanation for the incident, which has not become a tragedy, will soon be brought by NTSB and the necessary modifications to avoid another episode are even simple and fast to be made.
Although for customers like Alaska and United, the impact of having so many planes on the ground is significant, the 737 MAX 9 fleet is relatively small compared to the most popular 737 Max 8.
Of course, the problems for Boeing will not end with the solution of the case. The company, which is experiencing a long crisis of credibility, will be the target of public scrutiny again.
Government agencies should tighten the siege again in relation to the following failures to comply with safety protocols and the certification of models 737 MAX 7 and MAX 10 will be able to delay further.
The consequence is already being felt in the value of Boeing shares, which fell from $ 250 on the day of the incident to $ 218 a week later, or almost 13%.