A U.S. investigative authority sharply rebuked Boeing for sharing details about an ongoing probe of a near-catastrophic aviation incident that were not supposed to be discussed publicly.
The National Transportation Safety Board (NTSB) said that as a result, it will block Boeing from reviewing information gathered in its investigation.
Boeing "blatantly violated" investigative regulations under a signed agreement as a party to the probe, NTSB said in a statement late Wednesday.
The agency is also barring Boeing from asking questions of other participants at a two-day investigative hearing on the case which the NTSB will hold in early August in Washington.
The investigation concerns a January 5 Alaska Airlines flight on a Boeing 737 MAX that made an emergency landing after a fuselage panel blew out mid-flight.
Earlier this week, Boeing invited news media to a tour and briefings on its efforts to improve quality control. An AFP reporter attended the gathering, which was held on Tuesday under an agreement to embargo information until Thursday morning.
But NTSB said Boeing flouted the agreement "by providing non-public investigative information to the media and speculating about possible causes of the Jan. 5 door-plug blowout."
"As a party to many NTSB investigations over the past decades, few entities know the rules better than Boeing," the NTSB said.
Under the party agreement Boeing signed with the NTSB, the company is supposed to refer all comment on the Alaska Airlines probe to the agency.
Boeing apologized to the NTSB, saying it "stands ready to answer any questions as the agency continues its investigation," according to a company statement.
"We conducted an in-depth briefing on our safety & quality plan and shared context on the lessons we have learned from the January 5 accident," Boeing said.
"We deeply regret that some of our comments, intended to make clear our responsibility in the accident and explain the actions we are taking, overstepped the NTSB's role as the source of investigative information."
- What went wrong -
In a preliminary announcement in February, NTSB officials said four bolts securing the door plug were missing. Part of the NTSB probe centers on what went wrong.
The NTSB has taken issue with comments from Elizabeth Lund, senior vice president for quality at Boeing.
During a session with reporters, Lund discussed aspects surrounding work on the door plug.
She also said Boeing was focused on closing a "gap" over the lack of documentation and that determining who did the work "is the responsibility of the NTSB and that investigation is still going on."
NTSB responded that "in the briefing, Boeing portrayed the NTSB investigation as a search to locate the individual responsible for the door plug work."
"The NTSB is instead focused on the probable cause of the accident, not placing blame on any individual or assessing liability," the agency said.
The NTSB said it was also "coordinating" with the Department of Justice, which plans to soon announce next steps after concluding that Boeing could be prosecuted for violating a 2021 deferred prosecution agreement over two fatal MAX crashes.
The NTSB will provide DOJ "details about Boeing's recent unauthorized investigative information releases in the 737 MAX 9 door plug investigation," the NTSB said.