(NewsNation) — Boeing CEO Dave Calhoun met with Senators Mark Warner, D-VA and Dan Sullivan, R-AK, among others Wednesday to answer questions regarding the grounding of the 737 MAX 9.

Calhoun told reports his meeting with Warner was “constructive.”

“Shared everything I could — understands the gravity of the situation and we’re going to make sure that we convey our message in all the work that we’re doing, in our faith in our people and our airplane,” he said.

Calhoun added: “We believe in our airplanes. We feel they’re safe airplanes. Our people do. We have confidence in the safety of our airplanes and that’s what this is all about and we fully understand the gravity.”

The meeting follows a series of issues with Boeing passenger jets this year, most notably, the Jan. 5 incident in which a panel called door plug blew off an Alaska Airlines Boeing 737 MAX 9 jetliner 16,000 above Oregon, leaving a gaping hole in the side of the plane. The incident resulted in the FAA grounding most of Boeing’s MAX 9 jets.

Boeing declined NewsNation’s request for comment.

Calhoun is expected to meet with Sen. Ted. Cruz, R-TX, on Thursday. He’s also expected to meet with Sen. Maria Cantwell, D-WA, who chairs the Senate Commerce Committee.

Last week, Cantwell said she plans to hold a hearing after the Federal Aviation Administration (FAA) grounded 171 MAX 9 airplanes. A spokesperson for Cantwell said she was meeting with Calhoun at Boeing’s request.

Cantwell and Cruz held a closed-door briefing last week on the grounding with FAA Administrator Mike Whitaker and National Transportation Safety Board Chair Jennifer Homendy.

Numerous lawmakers on Capitol Hill have questioned Boeing. The company told Senators Ed Markey, JD Vance and Peter Welch in a previously unreported Jan. 17 letter that it was working to “restore trust with out regulators and our customers.”

Meanwhile, United Airlines has raised questions over billions of dollars of orders for MAX 10 jets.

United Airlines CEO Scott Kirby said on Tuesday the airline, which has ordered 277 MAX 10 jets with options for another 200, would build a new fleet plan that does not include a model already mired in regulatory and delivery delays.

Industry watchers have sought concrete signs that Boeing’s woes with the MAX 9 and the legacy of earlier MAX safety groundings are undermining support for the larger MAX 10, which makes up more than a fifth of outstanding MAX orders.

Boeing, which is under pressure from regulators and customers over quality control issues, said it would hold a quality stand down on Thursday at the Seattle-area location where it makes 737 aircraft, pausing production and delivery operations for a day.

The MAX 10 does not have the same kind of door-plug system as the MAX 9, but the grounding has raised concerns that the incident could delay regulatory approval and delivery of the MAX 10, as well as temper broader plans for higher production.

The FAA on Sunday urged operators of 737-900ER planes with door plugs to immediately inspect them after some airlines had noted “findings with bolts” during maintenance inspections.

Reuters contributed to this story.