Boeing performs pressure tests but does not normally adjust Max 9 panels -source

investing.com:

By Valerie Insinna and Tim Hepher

(Reuters) — Boeing (NYSE:BA) does not typically make adjustments to the type of panel involved in last week's 737 MAX 9 blowout unless factory tests reveal a problem, a source familiar with Boeing's industrial process said on Friday.

Sources told Reuters last week Boeing supplier Spirit AeroSystems (NYSE:SPR) sends semi-completed fuselages from its factory to Boeing with the special panel, which replaces an optional emergency exit, fitted but not completed.

Those sources said Boeing workers usually remove the panel, and use the gap to install pieces of cabin equipment, before replacing the panel and finishing the installation. But the source familiar with Boeing's industrial process said on Friday that according to its standard factory procedures, the company only removes or adjusts the panel if there are signs it was installed incorrectly. Boeing does perform certain checks and conducts pressurization tests before delivering the plane to the airline, the source said, adding that interiors are loaded elsewhere in the plane.

All the sources were speaking about standard production procedures, and not specifically about the Alaska Airlines jet that was forced to make an emergency landing a week ago because a panel had torn off mid-air and left a gaping hole in the fuselage.

A clearer understanding of the industrial processes involving Boeing's largest single-aisle plane will help investigators determine whether design or manufacturing played a role in the accident.

Boeing and Spirit AeroSystems declined to comment. Reuters could not independently verify the production practices, which are being investigated by the Federal Aviation Administration. The National Transportation Safety Board is