- Bloomberg has reported new details about what may have caused the Alaska Airlines door plug blowout.
- Unnamed sources say Boeing uses two systems to track the Max assembly, but they don't talk to each other.
New details have emerged regarding how the door plug on an Alaska Airlines Boeing 737 Max 9 blew off the jet mid-flight earlier this month.
The investigation is focused on four bolts that hold the door plug in place. The National Transportation Safety Board is trying to determine if they fell off during the event or if they were never installed to begin with.
Based on new information, it may be the latter.
On Wednesday, Bloomberg reported Boeing used multiple record-keeping logs to track actions made during the assembly of its 737 Max aircraft at its factory in Renton, Washington, citing two unnamed sources familiar with the blowout incident.
One system is the official log with the thousands of actions done on the aircraft, while the other is more informal, Bloomberg said.
Two anonymous sources, a Renton mechanic and a former 737 Max production line manager, gave the Seattle Times last week the same description regarding Boeing's two internal systems, with one source describing the informal log as a place to flag defects and "bring more eyes on what the problem is."
According to the unnamed sources at both publications, the problem with Boeing's multiple logs is they don't always talk to each other.
Hypothetically, work could be discussed in the informal system but never logged in the official one, meaning nothing would trigger further quality-control inspections on performed actions, Bloomberg reported.
In the case of the Max 9 involved in Alaska flight 1282, mechanics for Boeing and Spirit AeroSystems — the company that installs the door plug — appear to have messaged in the informal log about work needing to be done on the door plug.
It was reportedly here when they discussed and eventually agreed to open the door — which, regardless of whether it needs to be fully removed or just opened, requires the removal of the four critical bolts that secure the plug, per the Seattle Times.
However, because the opening of the door plug was reportedly never logged as an official action, nothing triggered a quality control check to ensure the bolts were reinserted.
According to Bloomberg, this disconnect between the two Renton systems may have caused a new Boeing 737 Max 9 plane to be delivered to Alaska without critical safety components.
Unnamed sources confirmed the same possible sequence of events to the Seattle Times, with one saying it was a Boeing employee who removed the door plug, not a Spirit AeroSystems worker.
The record-keeping lapse reports are so far from unnamed people familiar with the matter. Other anonymous sources have confirmed the same information to The New York Times as well.
"As the air safety agency responsible for investigating this accident, only the US National Transportation Safety Board can release information about the investigation," Boeing told Business Insider. "As a party to this investigation, Boeing is not able to comment and will refer you to the NTSB for any information."
Boeing pledged accountability on a call with investors
Boeing CEO Dave Calhoun told media during the company's fourth-quarter earnings call on Wednesday that "whatever conclusions are reached, Boeing is accountable for what happened."
"Boeing will get better, I am confident in that," he said later in the call. "We will address everything that needs to be learned from the accident, and we'll move forward."
As of Wednesday, the NTSB has not confirmed Boeing's multiple-system process but told BI, "We expect to issue our preliminary report on the Alaska Airlines flight 1282 accident in the coming days." The agency noted the release date and time will be posted on its X feed in advance.
The Federal Aviation Administration referred BI to Boeing for information on its internal systems. Spirit AeroSystems did not immediately respond to a request for comment from BI.
Boeing CEO says door plug installation will have inspections "at every turn"
The update comes three weeks after the Alaska blowout, which prompted the Federal Aviation Administration to ground 171 Max 9 planes with the same door plug.
The agency has since approved an enhanced maintenance process to get the grounded jets flying again, with carriers including Alaska and United Airlines already relaunching Max 9 passenger flights.
The FAA has also increased oversight at Boeing's factories: "First and foremost, we will run the door plug literally from the second a door is received at Wichita, through their lines, all 12 positions, through our 11 positions here, inspections will be added at every turn, it is on lockdown," Calhoun told media, speaking on quality system improvement.
The agency has halted Boeing's 737 Max production expansion while it addresses quality control lapses. The current Max output goal is 38 a month, according to Boeing.
"I'm sort of glad [the FAA] called out a pause, because that's a good excuse to just take our time, do it right, and I wish I had called that out on the first day," Calhoun said on Wednesday's call. "We've been good at taking pauses, I've probably taken more pauses in the last three years…than I have taken in the 10 years before it, but this is what we do and how we get better."
The CEO noted the several pauses in its 787 Dreamliner deliveries over the years to address quality problems, as well as slowed production rates on the 737 line to correct defects relating to improperly drilled holes on Max fuselages by Spirit AeroSystems.
Supply chain weaknesses have also contributed, he said.
"There are lots of sound reasons for why I'm feeling good," Calhoun said, noting increased inventory buffers to help stabilize production, as well as the respect demonstrated between Boeing and the FAA amid the Alaska event."In some ways, this moment will accelerate recovery, not delay it."