Whitaker testified during the committee’s hearing regarding the FAA’s regulatory oversight of Boeing and potential improvements in safety after the FAA limited Boeing’s production of its 737-MAX commercial aircraft.

Whitaker said a federal safety regulator and Boeing officials have improved safety since the Jan. 5 incident over Oregon in which a door plug blew off a 737-MAX aircraft operated by Alaska Airlines and forced it to make an emergency landing. No one was injured in the incident.

An investigation into the matter showed the door plug was installed without any securing bolts in place as required by the plug’s design.

Whitaker said a lot more work must be done and the FAA’s elevated oversight of Boeing’s aircraft production will continue.

“There must be a shift in the company’s safety culture to holistically address its systemic quality assurance and production issues,” he told committee members. “Our goal is to make sure Boeing implements the necessary changes and has the right tools in place to sustain those changes in the long term.”

Whitaker said the FAA has increased the number of safety inspectors reviewing the aircraft produced by Boeing and the parts produced and shipped by Boeing’s Spirit AeroSystems supplier.

Boeing founded Spirit AeroSystems years ago and spun it off into an independent company but recently re-acquired the aircraft parts supplier after the door plug failure.

Whitaker told the committee it will take between three and five years for Boeing to fully address problems with its quality control and the safety of its newly produced aircraft.

He said roving work at the Boeing factory was the root cause of the door plug blowout.

A current machinists strike by Boeing factory workers in Seattle and Oregon temporarily has stopped Boeing from implementing a safety training program designed to help overcome the production issues that affect aircraft safety and quality.