• Boeing's CEO said the company acknowledges "our mistake" after a part blew off a 737 Max 9 during an Alaska Airlines flight.
• The accident left a gaping hole in the fuselage.
• The FAA has grounded dozens of 737 Max 9 planes so they can be inspected.

Boeing CEO Dave Calhoun said the company acknowledges "our mistake," after a door plug on a 737 Max 9 blew out in the middle of an Alaska Airlines flight, creating a gaping hole in the fuselage and prompting a grounding of that aircraft type by federal regulations.

The Federal Aviation Administration grounded the 737 Max 9s less than a day after the incident on Alaska Airlines Flight 1282 so the jets could be inspected. Alaska on Wednesday said it would cancel all flights that were scheduled to use a 737 Max 9 through Saturday, amounting to 110 to 150 flights per day, while the inspections take place.

"When I got that picture [of the Alaska Airlines 737 Max 9], all I could think about — I didn't know what happened to whoever was supposed to be in the seat next to that hole in the airplane," Calhoun told Boeing staff during an all-hands meeting Tuesday, according to remarks shared by Boeing. "I've got kids, I've got grandkids and so do you. This stuff matters. Every detail matters."

No one was seated in 26A on the flight, which was next to the panel that blew out, saving passengers from a possible tragedy.

Fuselage manufacturer Spirit Aerosystems has also come under scrutiny as regulators seek to find out how the blowout — the result of what Calhoun called a "quality escape" — occurred.

"We're not going to point fingers there, because yes it escaped their factory, but then it escaped ours too," Calhoun told CNBC's Phil LeBeau on Wednesday.

Alaska Airlines and United Airlines, the two largest operators of the 737 Max 9, said on Monday that they have each already found loose parts on the same area of other Max 9s that underwent review.

The accident puts more scrutiny on Boeing and its CEO. The company has struggled with a string of defects on its planes over the past few years, while it tried to ramp up production and improve its reputation after fatal crashes in 2018 and 2019.

The company is also awaiting certification of its smaller Max 7 and largest Max 10 models. Calhoun told CNBC on Wednesday the Max 9 grounding shouldn't affect those approvals.

"This issue is on a discrete set of airplane," he said. "They're very much unrelated."

The FAA grounding does not affect the more common 737 Max 8, which is also in commercial use.

Calhoun said Tuesday that the company will work with the National Transportation Safety Board in its investigation and that the FAA is overseeing inspections "to ensure every next airplane that moves into the sky is in fact safe and that this event can never happen again."

— CNBC's Sara Salinas contributed to this report.

Don't miss these stories from CNBC PRO:

• There's one stock Wall Street loves so much for 2024 that five analysts in one day picked it as their favorite
• Morgan Stanley names its top stocks for 2024, including this streaming giant
• Investing tips from Warren Buffett to start the new year on the right foot
• Goldman sees a 50% gain ahead for this Chinese electric vehicle stock, initiates with buy rating
• 'Twice as cheap': These stocks' discount to the S&P 500 is double its average, Ritholtz's Brown says