The US Federal Aviation Administration is working to overhaul its internal processes for managing safety risks, the head of the agency plans to tell lawmakers at a hearing on Tuesday.

Boeing still has to make “significant changes” to improve the quality and safety of its airplanes, according to the head of the Federal Aviation Administration.

Boeing (BA) isn’t done doing what it needs to do in order to live up to the expectations of the Federal Aviation Administration in the wake of a January door plug blowout. Administrator Mike Whitaker said as much to Congress on Tuesday.

The head of the Federal Aviation Administration will tell Congress on Tuesday the agency will hold Boeing accountable to ensure the planemaker is building safe airplanes and will revamp its own safety management program.

The head of the Federal Aviation Administration told a U.S. House subcommittee Tuesday that safety culture improvements at Boeing may take three to five years to complete.

Boeing (NYSE:BA) has to make “significant changes” to improve the quality and safety of its airplanes, the head of the U.S. Federal Aviation Administration said in prepared remarks on Tuesday. Speaking at the latest congressional hearing on the agency’s oversight of Boeing (BA),