A key Boeing mechanic who worked on 737 Max doors was on vacation on 2 critical days before the Alaska Airlines blowout

• One Boeing mechanic was usually the only one who worked on door plugs, he told NTSB investigators.
• The 35-year veteran was on vacation during critical work on the Alaska Airlines 737 Max.
• A trainee with limited experience filled in, according to NTSB transcripts.

A Boeing mechanic who was usually the only one to work on door plugs was on vacation on two days that later proved critical to the Alaska Airlines blowout.

That's according to a transcript of the mechanic's interview with investigators published by the National Transportation Safety Board. The Seattle Times first reported the detail.

The mechanic has worked for Boeing for 35 years and on Boeing 737 doors since 1999. He told investigators he was part of a team of about 20 people, and said: "I think I'm the only one that can work on all the doors."

On January 5, an Alaska Airlines Boeing 737 Max was at an altitude of 16,000 feet when it lost a door plug — a fuselage panel that covers a deactivated emergency exit. The plane, delivered just 66 days earlier, left Boeing's factory missing key bolts designed to secure the door plug, the NTSB said in its preliminary report.

The jet was first worked on by Spirit AeroSystems before arriving at Boeing's plant in Renton, Washington. Workers then found damaged rivets near the door plug, so it had to be opened to replace the rivets.

On September 18, 2023, the day this work took place, the veteran mechanic was on vacation, The Seattle Times reported.

According to transcripts, the employee who filled in for the veteran mechanic was a trainee who had worked at Boeing for 17 months. He told investigators his only previous jobs were at KFC and Taco Bell.

The door plug was then closed by another worker. "I think somebody that was asked to do it that didn't really know that they were doing," the veteran mechanic told investigators.

No record of the door plug's opening and closing was entered into the system, so no quality inspection was conducted.

Boeing's Renton factory door team appeared to often face pressure. In the past three years, the veteran mechanic said he had about 15 managers.

At the end of his interview, he added: "The only thing I don't understand about the whole thing is, how come our shop wasn't contacted to open the plug? Usually, when something like that happens, I get asked to do that."

The veteran mechanic then confirmed that he was on vacation at the time.

Boeing did not immediately respond to a request for comment from Business Insider, made outside normal working hours.