Transportation Secretary Pete Buttigieg said Wednesday that all Boeing Max 9 airplanes would remain grounded until regulators deem them safe to fly, after one suffered an in-flight blowout of a fuselage panel last week, and dashing hopes for a quick return to the skies for the beleaguered jet.

“The only consideration is safety,” Buttigieg told reporters after an appearance at a transportation conference in Washington. “That’s going to dictate everything.”

He didn’t specify how long the process could take. “Nobody can or should be rushed in that process,” he said.

Also Wednesday, Alaska Airlines said it is canceling through Saturday all its flights on Boeing 737 Max 9 planes like the one that suffered the blowout as it waits for new instructions from Boeing and federal officials on how to inspect the fleet.

It was not clear Wednesday how Buttigieg’s statement would affect Alaska Air’s timetable.

Alaska and United airlines are the only U.S. carriers that fly the Max 9 jet.

The developments came as some travelers are trying to avoid flying on Max 9 jetliners — at least temporarily.

Flights canceled

Seattle-based Alaska Airlines said Wednesday that it would cancel 110 to 150 flights a day while the Max 9 planes remain grounded. By late afternoon, Alaska had canceled about 125 flights — one-fifth of its schedule for the day.

“We hope this action provides guests with a little more certainty, and we are working around the clock to reaccommodate impacted guests on other flights,” the airline said on its website.

United Airlines had canceled 167 flights because of the grounding order.

The Federal Aviation Administration grounded all Max 9s in the United States last Saturday, the day after an attached panel called a door plug blew off an Alaska Airlines jet over Oregon, leaving a hole in the side of the plane in mid-flight. The plug replaces extra doors that are used on Max 9s that are outfitted with more seats than Alaska uses.

The pilots of flight 1282 were able to return to Portland, Ore., and make a safe emergency landing. No serious injuries were reported.

Bolts missing?

Investigators with the National Transportation Safety Board said this week they have not found four bolts used to help secure the 63-pound door plug, and they are not certain whether the bolts were missing before the plane took off or broke during the flight.

The FAA approved inspection and repair guidelines developed by Boeing on Monday. However, on Tuesday the agency ordered Boeing to revise the instructions based on “feedback received in response.”

The order to revise the guidelines came after Alaska and United reported finding loose bolts and other problems in the panel doors of an unspecified number of other Max 9s that they had begun to inspect.

Buttigieg said that Boeing has to demonstrate that every plane it delivers to airlines is “100% safe.” This means “finding and fixing anything related to this issue, whether it’s directly or indirectly related,” as well as “anything that surfaces in the inspections that are taking place.”

Formal inspections have yet to start.

Boeing damage control

Boeing CEO David Calhoun said a Boeing engineer was present during some of the Alaska checks, “and yes, he used that term, loose bolt.”

Asked how the plane was allowed to fly in the first place, Calhoun said on CNBC, “Because a quality escape occurred.”

Boeing said Wednesday that it was updating inspection procedures based on comments from FAA and the airlines, and the FAA repeated an earlier pledge to let safety determine when the planes fly again. Neither would say how long that might take.

The door plugs are installed by Boeing supplier Spirit AeroSystems, but investigators have not said which company’s employees last worked on the plug on the ill-fated Alaska plane.

Earlier this week, Calhoun told employees at the 737 factory in Renton, Wash., that the company was “acknowledging our mistake ... and that this event can never happen again.”

Travelers respond

Some travelers are watching the unfolding investigation too.

Kayak, a travel-search site owned by Booking Holdings, said Wednesday that after the blowout on the Alaska flight, it saw a three-fold jump in the number of people filtering their searches to isolate the type of aircraft. The jump — from low numbers, a Kayak spokeswoman acknowledged — led the site to make its airplane-type filter easier to find.

“Anytime an aircraft model becomes a household name, something has gone wrong,” said Scott Keyes, founder of the travel site Going.

This report contains information from Bloomberg News and the Associated Press.