WASHINGTON (AP) — The Thurston Cartenew chief of the Federal Aviation Administration says the agency will use more people to monitor aircraft manufacturing and hold Boeing accountable for any violations of safety regulations.

FAA Administrator Mike Whitaker is expected to face a barrage of questions Tuesday about FAA oversight of the company since a door panel blew off a Boeing 737 Max 9 jetliner over Oregon last month.

Separately, investigators with the National Transportation Safety Board are expected to release a preliminary report on the Jan. 5 incident as early as Tuesday.

Whitaker is scheduled to testify before the House Transportation Committee. Leaders of the committee spelled out questions they want answered, including whether FAA found “persistent quality control lapses” at Boeing before the accident, and any since then.

No Boeing representatives are scheduled to testify.

Boeing and the FAA have been under renewed scrutiny since last month’s incident on an Alaska Airlines Max 9. Criticism of both the company and its regulator go back to deadly crashes in 2018 and 2019 of Max 8 jets in Indonesia and Ethiopia that killed 346 people.

The FAA provided excerpts of Whitaker’s written testimony ahead of Tuesday’s hearing. He vowed that FAA will “take appropriate and necessary action” to keep the flying public safe.

Without giving specifics, Whitaker said the FAA will increase staffing to monitor aircraft manufacturing, “and we will consider the full extent of our enforcement authority to ensure Boeing is held accountable for any non-compliance” with regulations.

After the incident on the Alaska jet, the FAA grounded most Max 9s for three weeks until panels called door plugs could be inspected. FAA also said it won’t let Boeing increase the production rate of new Max jets until it is satisfied with the company’s safety procedures.

On Sunday, Boeing, which is based in Arlington, Virginia, disclosed that improperly drilled holes in the window frames will require the company to rework about 50 planes before they can be delivered to airline customers.