Boeing stated that it "believes that the documents required to explain the reason for removing a key part during the manufacturing of a 737 Max 9 aircraft do not exist at all," according to a letter seen by Reuters. The aircraft faced an emergency during flight in January. Ziyad Ojakli, Boeing's Executive Vice President, mentioned in the letter to Senator Maria Cantwell, "We have searched extensively and found no such documents." Jennifer Homendy, Chair of the National Transportation Safety Board, criticized Boeing on Wednesday for what she described as "lack of cooperation and failure to disclose certain documents," including those related to opening and closing the door plug, as well as the names of 25 people involved in manufacturing this part of the aircraft (the door plug) at a Boeing facility in Renton, Washington. She said during a Senate Commerce Committee hearing, "It is ridiculous that we have not received what we requested after two months." Following the incident, which did not result in any injuries, the Federal Aviation Administration grounded Max 9 aircraft for several weeks in January, restricting Boeing from increasing the production rate of the Max and ordered them to develop a comprehensive plan to address "systemic quality control issues" within 90 days.