A panel of experts has identified “inadequate and confusing” safety processes at Boeing and a “disconnect” between senior managers and the rank and file in a report that raises new questions about operations at the US aircraft manufacturer after a door panel blew out of one of its planes last month.

The 50-page report was commissioned long before the incident on an Alaska Airlines 737 Max jetliner in January. It scrutinises safety culture, safety management systems and a federal programme, known as Organization Designation Authorization, which allows federal aviation regulators to assign the authority to inspect planes to Boeing employees.

The Federal Aviation Administration said it will would review the report as it conducts an audit of Boeing after the door-panel incident. A preliminary probe by the National Transportation Safety Board found four bolts were missing from the door opening when the Alaska Airlines plane left a Boeing factory last year.