(Bloomberg) -- US Senator Chuck Grassley announced Friday he’s launching a congressional inquiry into Boeing Co. and the Federal Aviation Administration, adding to the mounting scrutiny the regulator and embattled planemaker have faced since a panel blew off a 737 Max mid-flight earlier this year. 

“Boeing’s track record, as well as recent reports, demonstrate that aircraft safety has not been the paramount concern and the FAA has provided insufficient oversight to ensure that it is,” Grassley, a Republican from Iowa, said in one of two letters sent to Boeing Chief Executive Officer Dave Calhoun and FAA Administrator Michael Whitaker earlier this week. 

Boeing and the FAA have come under intense scrutiny since the Jan. 5 accident, which involved an Alaska Airlines flight. Representatives for both have been called up to Capitol Hill for hearings and a number of government agencies, including the Justice Department and the Securities and Exchange Commission are investigating Boeing over the near-catastrophe. 

Boeing said in a statement that it “will continue to be responsive and transparent with Congress” when asked about the Grassley inquiry. The FAA said it will respond directly to the senator. 

In the letters, the senator questioned the planemaker on its safety culture and a lack of documents to explain how the plane left Boeing’s factory missing bolts to keep the panel in place. To the FAA, he lobbed questions about the agency’s oversight and whether it had changed any of its rules or policies in response to the event. He asked a total of 38 questions. 

In response to the January accident, the FAA capped production of the 737 Max and required Boeing to submit a sweeping plan to address quality issues at its factories. 

Whitaker appeared before the Senate Commerce Committee Thursday to discuss the plan. Calhoun is slated to testify before a separate Senate panel next week. 

Whitaker shouldered some of the blame in a conversation with reporters following the Thursday hearing. “Boeing makes the airplanes and Boeing’s responsible, but we’re also responsible for oversight so we should have had a better handle on what was going on,” he said.

--With assistance from Julie Johnsson.

(Updates with comments from Boeing and the FAA in fourth paragraph)

©2024 Bloomberg L.P.