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.

The US Federal Aviation Administration is working to overhaul its internal processes for identifying and addressing aviation safety risks in the wake of a mid-air blowout on a Boeing Co. jet, the agency’s top official plans to tell lawmakers on Tuesday.

After two crashes of Boeing 737 Max airplanes and a door plug that fell off of another, mid-flight, FAA Administrator Michael Whitaker testified before the House of Representatives about his agency’s oversight of Boeing.

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.

Boeing must do more to improve the aircraft safety following a door plug blowout in January and other mishaps, Federal Aviation Administration Administrator Mike Whitaker told a House committee Tuesday.

The head of the Federal Aviation Administration told a U.S. House subcommittee on Tuesday that safety culture improvements at Boeing may take three to five years to complete. "It is not a six-month program - it is a three-year to five-year program,

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.