Alaska Airlines flight lost a section of fuselage: Here's how the investigation is going

An Alaska Airlines flight from Portland, Oregon, to Ontario, California, made a dramatic emergency landing late Friday night after a piece of the fuselage burst off at 16,000 feet.

All the passengers and crew onboard deplaned safely in Portland – surely shaken up – but the flight, which was operated by a Boeing 737 MAX 9 jet, represents just the latest high-profile issue for that troubled narrowbody program.

Here’s where things stand as we head into the week.

What happened to Alaska Airlines flight 1282?

Shortly after taking off from Portland, a mid-cabin door plug separated from the fuselage.

The plug was in place because some manufacturers configure their planes in a way that requires more emergency exits onboard. Alaska’s seating configuration did not require that extra exit, so the door frame was blocked instead.

According to the airline, some passengers had injuries that required medical attention after landing, but they have all since been cleared.

“This is a very serious event,” Anthony Brickhouse, director of the Forensic Crash Lab at Embry-Riddle Aeronautical University, told USA TODAY. “We’re very lucky this happened at 16,000 feet instead of 35,000 feet. The results could have been catastrophic.”

Had the incident happened at a higher altitude, Brickhouse said the decompression likely would have been more violent and could have led to more significant structural damage to the aircraft.

“We could easily be talking about a fatal accident if this had happened at 35, 36,000 feet,” he said.

Are Boeing 737 MAX planes still flying?

Some are, but not all. There are two variations of Boeing 737 MAX jets in operation right now: the MAX 8 and MAX 9. A smaller MAX 7 and larger MAX 10 are also expected to enter service this year, pending final regulatory approvals. The plane involved in Friday night’s incident was a MAX 9, and the Federal Aviation Administration has since ordered the grounding of some aircraft of that variant pending inspections of the affected area of the fuselage.

The order affects about 171 planes worldwide. Alaska Airlines and United Airlines are the main operators of the MAX 9 in the U.S. and expect the grounding to significantly impact their operations in the coming days.

“The 737-9 MAX grounding has significantly impacted our operation. We have canceled 170 Sunday flights and 60 cancellations for Monday, with more expected,” Alaska Airlines said in a statement Sunday night. “Cancellations will continue through the first half of the week, and we encourage guests with travel plans to continue to check their email and alaskaair.com for updates.”

Transportation Secretary Pete Buttigieg said in a statement on social media that the Department of Transportation prioritizes safety and he supports the FAA’s grounding decision.

United Airlines confirmed in a statement to USA TODAY on Monday that it has discovered issues with some of its MAX 9s already.

"Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug – for example, bolts that needed additional tightening. These findings will be remedied by our Tech Ops team to safely return the aircraft to service," the statement said.

What problems have Boeing 737 MAX planes previously had?

Boeing’s 737 MAX jets have had a series of issues since entering into service. Two MAX 8 planes, one operated by Lion Air in Indonesia and one by Ethiopian Airlines in Ethiopia, crashed within about six months of each other, killing 346 people between them. Both crashes were attributed to an automated flight control software known by its acronym MCAS, which Boeing developed to compensate for the new generation 737’s changed aerodynamics compared to previous versions of the jet.

The crashes resulted in the worldwide fleet of 737 MAX being grounded for more than a year and a half, from March 2019 to November 2020.

Cruising Altitude: Learn more about airplane layouts and seating configurations

What can you do if your flight is affected?

Both Alaska and United are offering flexible rebooking policies if your flight is affected by the current grounding order.

Check with your airline and keep an eye out for notifications if you think your travel could be impacted.

How can you find out what kind of plane is scheduled to operate your flight?

Airlines typically show what kind of planes are scheduled under flight details when you go to book, and in your reservation once your ticket is confirmed. MAX jets sometimes show up as 737-8 and 737-9 (not to be confused with 738 and 739, which typically represent an older, less troubled generation of the narrowbody).

Trip search engine Kayak also allows users to search for flights by aircraft model, including differentiating between MAX 8 and MAX 9 jets.

Story continues below.

What’s happening with the Alaska Airlines flight investigation?

The National Transportation Safety Board has taken over investigating the incident, but it will take a while before an official report and accounting of the incident is published.

In the meantime, officials said the door plug that separated from the aircraft was found in the backyard of a teacher in Oregon.

“They’re gathering facts and information so that they can do analysis. They’re looking at the aircraft itself. They’re going to be looking at that piece that was found in the backyard,” Brickhouse said. “The investigation is well underway.”

Brickhouse said one of the key questions investigators will seek to answer is whether the issue that occurred on Friday was caused by a problem with the specific aircraft involved in the incident, or if it’s a broader problem affecting Alaska’s entire fleet of MAX 9s or all MAX 9s regardless of operator.

“The NTSB is investigating and normally it can take over 12 months to complete an investigation, but if they find something in the next few days that is critical to the safety of flight, they’ll make an immediate emergency recommendation,” Brickhouse said. “The planes will remain grounded until they can be inspected and once they are inspected and can pass certain criteria, I would expect them to be back in the air,” though he added it’s unclear how long that might take.

In a statement, the FAA said it has approved a procedure for the inspections.

"The FAA’s priority is always keeping Americans safe. In that spirit, Boeing 737-9 aircraft will remain grounded until operators complete enhanced inspections which include both left and right cabin door exit plugs, door components, and fasteners," the statement said. "Operators must also complete corrective action requirements based on findings from the inspections prior to bringing any aircraft back into service."

What are some of the limitations to aircraft incident investigations?

Every aircraft accident and incident investigation is different. Still, investigators typically rely on physical evidence, like the door plug in this Alaska Airlines case, as well as some onboard machinery known as the black boxes – or cockpit voice recorders and flight data recorders.

One of the limitations of cockpit voice recorders is they typically only record about two hours’ worth of audio, which can lead to unanswered questions if the incident occurred after a longer flight.

Brickhouse said that even though this incident took place just minutes after takeoff, the cockpit voice recorder continued recording after the plane landed, and by the time investigators retrieved it, all of the audio from the incident had been overwritten.

He added that the NTSB has been pushing the FAA for years to require longer-duration recorders on commercial aircraft, and said that this incident clearly demonstrates the value of that suggestion.

Is flying still safe?

Yes.

Despite two high-profile incidents this year – the Alaska Airlines decompression over the weekend and Japan Airlines’ fiery crash earlier last week – flying is still seen as a very safe way to travel. Five members of the Japanese Coast Guard were killed when the Japan Airlines jet struck their plane on the runway at Haneda Airport in Tokyo, but there have been no fatalities on commercial jets so far this year, despite the shocking images that have come out of the incidents.

But Brickhouse said passengers also have a role to play in their safety.

“From a passenger safety point of view, this event clearly illustrates, along with the Japan Airlines accident last week, it’s really important to listen to the safety briefing,” he said, adding that it’s a good idea to stay buckled up as much as possible while flying. “Regardless of what that light is telling you, always keep your seatbelt buckled.”

Zach Wichter is a travel reporter for USA TODAY based in New York. You can reach him at zwichter@usatoday.com

This article originally appeared on USA TODAY: What to know about Boeing 737 MAX jets after Alaska Airlines incident