WASHINGTON — The flying public can expect more details about what caused a panel to explode off a Boeing 737 MAX plane earlier this year as the top U.S. aviation investigator presents evidence and testimony on the near-disaster during a two-day hearing.
Boeing executives will appear before the National Transportation Safety Board on Tuesday and Wednesday for a fact-finding hearing, part of the NTSB’s monthslong investigation into what went wrong.
The hearing will focus on Boeing’s production and inspection processes, as well as workforce training at the aerospace giant and documentation meant to track airplane parts as 737s move through Boeing’s Renton factory. Investigators will also share what they know about the circumstances leading up to the Jan. 5 blowout over Portland.
The panel, known as a door plug, which fills a hole left for an extra emergency exit installed in some aircraft, blew off as an Alaska Airlines flight was climbing into the sky out of Portland. The plane landed safely, with some passengers reporting non-life-threatening injuries and distress.
But Boeing narrowly avoided a catastrophic disaster. If the blowout had occurred later in the flight when the plane was at a higher altitude, or if passengers had been sitting in the seats closest to the door plug, the incident could have been deadly.
The NTSB has already released some preliminary findings that, so far, indicate that things went wrong in Boeing’s Renton factory.
Before heading to Renton by train, the fuselage of the plane was assembled at Spirit AeroSystems, a Boeing supplier based in Wichita, Kan. Spirit has also come under scrutiny for manufacturing defects, and Boeing recently secured a deal to buy the troubled manufacturer in an effort to revitalize both companies.
In Renton, the NTSB found, Boeing mechanics partially removed the door plug to complete other work on the plane.
Out-of-order work, which allows mechanics to move planes through its factory lines before completing all jobs in the standard order, was common at Boeing at the time. It kept production rates up, but also increased the risk of mistakes as workers take parts on and off planes.
In the case of the door plug, Boeing workers reinstalled the panel but did not properly install four bolts meant to hold the plug in place. It’s likely the bolts were not installed at all.
The plane flew for two months without the bolts, before the door plug came loose in January.
Following that incident, Boeing’s airline customers, including Alaska and United Airlines, inspected the rest of their Boeing 737 MAX 9 fleets and discovered other planes with loose bolts.
It’s not clear who should have been responsible for putting them back on. Boeing has said it doesn’t have any record of the work being done.
The lack of documentation will be a topic of scrutiny at the NTSB hearing. The board intends to examine what processes Boeing has in place, how they are supposed to work, and what went wrong in this instance.
The board will also discuss mechanisms for employees to report safety concerns and how Boeing makes the decision to stop a plane from moving forward in the factory based on those reports. On the second day, the NTSB will examine Boeing’s safety management system and the Federal Aviation Administration’s oversight of the company.
Boeing’s senior vice president of quality, Elizabeth Lund, is expected to testify, as is Doug Ackerman, the vice president of supplier quality; Paul Wright, senior director for Boeing’s safety management system; and Hector Silva, director of quality.
Several Spirit AeroSystems executives will also testify, as well as members of the FAA and a representative from the International Association of Machinists, which represents Boeing employees.
The door plug blowout reignited scrutiny about two fatal crashes involving Boeing’s 737 MAX five years ago.
In those incidents, an error with a then-new software system on the MAX led to two crashes that killed 346 people. Boeing recently pleaded guilty to misleading safety regulators about that software system, affecting the certification of that new model. As part of the guilty plea, Boeing has agreed to an independent monitor watching the company’s compliance with federal safety regulations for the next three years.
Boeing CEO Dave Calhoun, who took over after the fatal crashes, resigned after the door plug incident. Boeing named Kelly Ortberg, former executive at supplier Rockwell Collins, to take over. Ortberg’s first day is Thursday, immediately after the NTSB hearing wraps up.
