4 things to know about Boeing and Alaska Air 1282

Boeing and US air travel are still facing the fallout a week after the dramatic in-flight door plug blowout on an Alaska Airlines Boeing 737 Max 9 last Friday.

The door plug — a portion of the plane’s fuselage the manufacturer can put in place instead of an emergency exit door — detached from the plane and was later found in an Oregon backyard.

171 Boeing Max 9s remain grounded in the United States as of Friday as airlines Alaska and United await updated emergency inspection guidance from the Federal Aviation Administration.

The FAA said Thursday it is opening an investigation into Boeing’s quality control due to the failure of the door plug. The National Transportation Safety Board is conducting its own investigation, separate from the FAA.

On Wednesday, Boeing CEO Dave Calhoun admitted in an interview with CNBC that the door plug failure was a “horrible escape” of its manufacturing and quality control processes.

When asked what happened, Calhoun told CNBC, “What happened is exactly what you saw, a fuselage plug blew out. That’s the mistake, it can never happen.”

Here are the latest updates on Boeing and the effects of Alaska Air flight 1282.

On Friday, the United States faced the highest number of cancellations in six months. That’s thanks to a combination of winter weather and the continued grounding of Boeing 737 Max 9 planes.

There were more than 2,000 cancellations as of Friday afternoon.

Most of the cancellations are due to a winter storm that is pounding the Midwest. Chicago’s two major airports are seeing the bulk of the cancellations, with nearly 40% of departing flights at O’Hare and more than 60% of departing flights at Midway, according to FlightAware Friday afternoon.

But the grounding of 737 Max 9 planes has exacerbated the issue. More than 200 United and Alaska Airlines flights have been canceled each day this week due to last Friday’s FAA-mandated grounding. The FAA and Boeing are still trying to settle on an inspection protocol that would allow those planes to resume flying.

The Federal Aviation Administration said Friday its audit of the Boeing 737 Max 9 “production line and its suppliers” will focus on quality control.

The audit will also assess “safety risks around delegated authority and quality oversight,” a practice that FAA Administrator Mike Whitaker said in a statement “is time to re-examine.”

Whitaker said the agency is also considering the use of a third party for the audit.

A class action lawsuit was filed Thursday in Washington state against Boeing on behalf of the passengers aboard last week’s Alaska Airlines flight 1282.

According to the lawsuit’s allegations, “the event physically injured some passengers and emotionally traumatized most if not all aboard. The violence of the event bruised the bodies of some” and “passengers were shocked, terrorized and confused, thrust into a waking nightmare, hoping they would live long enough to walk the earth again.”

Some of the plaintiffs listed in the lawsuit cited various injuries they allegedly suffered as a result of the incident, including “difficulty breathing,” “causing a concussion” and a loss of hearing.

In addition to injuries, other damages were claimed such as “charges for evaluation and/or treatment of health conditions and associated travel expenses, ticket fees, costs associated with cancelation of travel plans, the value of lost personal items, lost wages,” etc.

The lawsuit is requesting a trial to determine the damage amounts.

Boeing did not have comment.

Some aviation experts raised questions about the structural design of the section of the Boeing 737 Max 9 that blew off the plane.

In interviews with CNN, the experts argued that if the door plug were designed to be larger than the opening it covers and installed inside the plane, the force of the pressurized air in the passenger cabin would force the plug against the plane’s interior frame and a situation such as the one on the Alaska Airlines flight could have been avoided. However, such a design could have added costs and practical disadvantages, some said.

“It doesn’t make sense to me why they would do it that way and not have it installed from the inside, where it literally cannot come out unless there is a structural failure in the airframe,” said David Soucie, a former FAA safety inspector and CNN analyst. “Historically, since we have had pressurized airplanes, emergency exits are designed to come inward… so why would they have not done the same thing with this plug?”

— CNN’s Joe Sutton, Pete Muntean, Curt Devine, and Ross Levitt contributed to this report.