According to a preliminary report released yesterday, a quality notification (QN) was issued due to a minor seal tolerance issue by “0.01 inches”.

“No manufacturing rework was required, as Spirit AeroSystems Engineering determined the condition was structurally and functionally acceptable and did not adversely affect the form, fit, or function of the installation,” NTSB said.

“There were no other QNs for the left mid-exit door plug before leaving Spirit AeroSystems. (The) fuselage (was) shipped to Boeing on Aug 20, 2023.”

The board’s full investigation is expected to last up to a year before final conclusions are drawn regarding the Jan 5 incident.

The report also said the door plug was manufactured by Spirit AeroSystems in Malaysia on March 24, 2023, and reached Boeing’s supplier in Wichita, Kansas, on May 10 of the same year.

After it was determined that no manufacturing rework was needed, the fuselage was shipped to Boeing on Aug 20, 2023, and arrived at the Renton facility in Washington on Aug 31.

Investigators also discovered that four bolts used to secure the door plug to the fuselage were missing.

The blown-out door plug captured local media attention after a news portal known as Oregon Public Broadcasting (OPB) reported that Portland school teacher Bob Sauer had allegedly discovered the door plug torn from the aircraft in his backyard.

OPB reported that Sauer found manufacturing details, including the words “Made in Malaysia”, apparently handwritten on the door in permanent marker.