A US regulator imposed sanctions on <a href="https://www.thenationalnews.com/tags/boeing/" target="_blank">Boeing</a> on Thursday for sharing non-public details about the government's investigation into the <a href="https://www.thenationalnews.com/business/markets/2024/01/09/boeing-stock/" target="_blank">Alaska Airlines</a> door-plug incident that occurred this year during a <a href="https://www.thenationalnews.com/world/us-news/2024/01/06/alaska-airlines-grounds-boeing-737-max-9-planes-after-window-blows-out/" target="_blank">737 Max 9</a> flight. The National Transportation Safety Board (NTSB) said Boeing had “blatantly violated” the agency's regulations when the embattled plane manufacturer provided information on the investigation and speculated about the cause of the incident at a media briefing on Tuesday. A transcript of the briefing provided to the NTSB showed Boeing revealed non-public information to the media that the regulator had neither verified nor authorised for release. It also showed Boeing “offered opinions and analysis on factors it suggested were causal to the accident”. The NTSB said those actions are prohibited by an agreement Boeing signed when it was offered party status by the regulator at the beginning of the investigation. “As a party to many NTSB investigations over the past decades, few entities know the rules better than Boeing,” the regulator said. Boeing will retain its party status but will no longer have access to investigative information on regulatory produces, the NTSB added. Boeing said it regretted that some of its comments during the briefing had overstepped the NTSB's role as the source of investigative information. "We apologise to the NTSB and stand ready to answer any questions as the agency continues its investigation," a Boeing statement read. During the Alaska Airlines flight in January, a door plug blew off the plane while it was flying 16,000 feet above Portland, Oregon. Boeing has faced intense scrutiny in the months since as well as a number of federal investigations. Chief executive <a href="https://www.thenationalnews.com/business/aviation/2024/03/25/boeing-ceo-dave-calhoun/" target="_blank">Dave Calhoun</a> is due to step down at the end of the year. During an intense congressional hearing this month, politicians accused him of putting the company's profits before safety. Boeing is also accused of mischaracterising the investigation as a search to locate the person who had worked on the door plug. “The NTSB is instead focused on the probable cause of the accident, not placing blame on any individual or assessing liability,” it said. The regulator said it will subpoena Boeing to appear at an investigative hearing on August 6-7. It will also co-ordinate with the Justice Department's fraud division to provide details about the unauthorised releases. The Justice Department is already considering <a href="https://www.thenationalnews.com/news/us/2024/05/15/boeing-at-risk-of-us-prosecution-for-breaching-deal-over-crashes/" target="_blank">whether to prosecute Boeing</a> for breaking the terms of an agreement after two fatal crashes in 2018 and 2019 that resulted in the deaths of 346 people. The department previously said it would inform the court by July 7 on how it wishes to proceed.