National Transportation Safety Board Chair Jennifer Homendy said Tuesday that the heroic actions of the crew aboard Alaska Airlines flight 1282 ensured everyone survived the terrifying incident last year when a door plug panel flew off the plane shortly after takeoff.

But Homendy said “the crew shouldn’t have had to be heroes, because this accident never should have happened.” She noted that it wouldn’t have if Boeing and the Federal Aviation Administration had done enough to ensure the safety of the Boeing 737 Max aircraft.

An NTSB investigation over the past 17 months found that bolts securing what is known as the door plug panel were removed and never replaced during a repair.

Boeing and Spirit AeroSystems — the company that made and installed the door plug — are redesigning them with another backup system to keep the panels in place even if the bolts are missing, but that improvement isn’t likely to be certified by the FAA until 2026 at the soonest.And the NTSB has found bigger problems.

“An accident like this only happens when there are multiple system failures,” Homendy said.

Both Boeing and the FAA have improved training and processes since the incident, according to the NTSB, but board officials said both organizations need to better identify manufacturing risks to make sure such flaws never sneak through again. Homendy did single out Boeing’s new CEO, Kelly Ortberg, for improving safety since he took over last summer, though she said more needs to be done.

The NTSB is expected to approve several recommendations at Tuesday’s meeting. It already highlighted how Boeing needs to ensure that everyone throughout the company understands its safety plan as well as executives do.

The FAA must also step up to make sure its audits and inspections focus on key areas based on past problems, according to the safety board.

The blowout aboard Alaska Airlines flight 1282 occurred minutes after it took off from Portland, Oregon, and created a roaring air vacuum that sucked objects out of the cabin and scattered them on the ground below along with debris from the fuselage. Seven passengers and one flight attendant sustained minor injuries, but no one was killed. Pilots were able to land the plane safely back at the airport.

Oxygen masks dropped and phones went flying

The accident occurred as the plane flew at 16,000 feet (4,800 meters). Oxygen masks dropped during the rapid decompression and a few cellphones and other objects were swept through the hole in the plane as 171 passengers contended with wind and roaring noise.

The first six minutes of the flight to Southern California’s Ontario International Airport were routine. The Boeing 737 Max 9 was about halfway to its cruising altitude and traveling at more than 400 mph (640 kph) when passengers described a loud “boom” and wind so strong it ripped the shirt off someone’s back.

“We knew something was wrong,” Kelly Bartlett told The Associated Press in the days following the flight. “We didn’t know what. We didn’t know how serious. We didn’t know if it meant we were going to crash.”

The 2-foot-by-4-foot (61-centimeter-by-122-centimeter) piece of fuselage covering an unused emergency exit behind the left wing had blown out. Only seven seats on the flight were unoccupied, including the two seats closest to the opening.

NTSB member J. Todd Inman said the Alaska Airlines accident would have been worse if it had happened over the ocean and far from land, but the carrier had already restricted the plane used for flight 1282 to overland flights because of an unresolved maintenance issue with a fuel pump. The airline took that step on its own, going above FAA requirements, Inman said.