The ‘Cultural’ Questions that Follow the Alaska Airlines Blowout.
The ‘Cultural’ Questions that Follow the Alaska Airlines Blowout.
Did this episode have anything to do with the recent rash of aviation ‘close calls’? Almost certainly not. But it may illustrate a different systemic problem.
The inside of the Boeing 737 MAX 9, flown by Alaska Airlines, after its “explosive decompression” at 16,000 feet. No passenger was sitting next to what became a gaping hole. (AP)
Two days ago, late Saturday afternoon, I stepped off a United Airlines flight at Dulles airport, outside Washington, and stepped into a scene resembling a Tokyo subway station at rush hour. Travelers with their bags and backpacks seemed to cover every inch of the floor space, and this at a time of week that usually had lighter crowds.
As I shouldered my way down the concourse, I noticed the endless queues at the United “Customer Service” desk and at some United check-in gates. In passing I caught part of one agent’s announcement: “… we have just been notified that we can’t use this particular aircraft. We are now looking for a replacement, and we ask that you …”
I’d been away from the news and only later figured out that I’d been seeing early ripple effects of the 737 MAX 9 emergency on an Alaska Airlines flight the previous evening, and the FAA’s grounding order for similar planes. The order affected United and Alaska, the two US airlines flying the MAX 9 model.
This post will be Q-and-A style, with two areas of focus. One is sources of information you can follow for still-emerging details about the plane, the problem, and the possible explanations for what happened. (Standard reminder: Early guesses about aviation problems often turn out to be wrong.) The other is larger issues of air safety the episode might highlight.
Breaking news update: Jon Ostrower in The Air Current reports that United Airlines has found “loose bolts” in at least five of the Boeing 737 MAX 9 airplanes it has inspected. More below on why this matters and what it might mean.
1) What happened?
On Friday Alaska Airlines flight 1282 left Portland, Oregon, headed toward Ontario, in inland Southern California. As the plane climbed to 16,000 feet, toward its expected cruise altitude above 30,000 feet, a panel in the left side of the fuselage blew out.
From the inside of the plane, the results were what you see in the image at the top of this post. From the outside, they looked like this:
The interior and exterior views are significant, in showing what a “clean” structural break this was. Technically you could call what happened an “explosive decompression,” since pressurized air inside the cabin pushed the door/wall out into the thinner air. But the damage did not resemble the ragged edges of an “explosion” in the normal sense of the term. As we have all heard, the aviation term for the part that failed is a “door plug,” and the damage looks just like a plug that was popped out.
For reasons I haven’t seen explained—pure luck? some awareness of risks in assigning seats?—no passengers had been assigned the seats immediately next to the door-sized hole.
1A) By the way, was this a ‘door’? Or a ‘wall’? Or a ‘plug’? Or what?
It was all of them. From inside the plane, it would look just like a wall. From outside, it had the shape of an emergency-exit door. In between was the “plug,” replacing the emergency exit that would be installed in some models of this plane.
Everything you could possibly want to know about doors, plugs, and “deactivated exits” is clearly and extensively covered in this YouTube video, from a longtime 737 pilot named Chris Brady at the channel called “The Boeing 737 Technical Channel.” For any technical questions, please start there.
This video also answers in great detail a question many passengers might have: Why aren’t doors and exits popping open on airplanes all the time? The reason, to oversimplify, is that they are designed to make air-pressure differentials at high altitude a safety feature, rather than a safety threat. More on this below.
2) Where did the plane go? And how did it get safely to the ground?
As for the where: from a FlightRadar24 map, here is the track of the plane. It took off from Portland to the northwest and made a climbing left-hand turn toward its en-route heading to the southeast. It had reached a speed of more than 400 mph and an altitude of around 16,000 feet when the door plug blew out. Then it managed an emergency return to Portland through the rest of the left-hand circuit. You can see another view of its track on FlightAware.
As for the how: I very highly recommend this gripping overlay of the flight’s course, with transmissions between the flight crew and people on the ground. It is from the “You can see ATC” channel on YouTube, and it will be self-explanatory if you watch it:
One thing to notice: how often the pilot working the radio1 tries to convey the situation—We are declaring an emergency. We are depressurized—to controllers who at first are a beat slow in recognizing what has happened.
We have learned now that the cockpit door blew open when air whooshed out of the plane.2 The flight crew would have immediately put on their emergency oxygen masks. In the first moments of transmission you can hear both the stress in the cockpit and the garble that may have come from the pilot’s trying to talk through the bulky mask.
If you watch the whole depiction, you’ll see all involved—flight crew, controllers, operators of fire-trucks and other emergency equipment on the ground—doing the usual grace-under-pressure job. Listen to them, and imagine everyone else facing life-and-death stakes with such aplomb.
Here’s another re-creation, from Avocado Flight on YouTube, which of course tells the same story with some different illustrations.
3) Would this have been frightening?
God, yes.
To have a hole in the side of the airplane, while you’re traveling at hundreds of miles per hour with very cold, very thin air just inches outside, is one of the two primal terrors of being in the sky. (What is the other? The nightmarish horror of being inside a plane and knowing that it is headed toward the ground.)
As I never tire of saying, being aboard an airliner in North America or Europe is statistically the very safest thing you can do. But statistics only mean so much when you’re looking through a hole out at the ground.3
3A) And apart from terrifying, exactly how dangerous would it have been?
As many reports have noted, this very same airplane had logged problems with its air-pressure sensors in recent flights. As a result, Alaska had taken it off long over-water routes, like ones to Hawaii.
We’ll see what connection those early reports may have had with the Flight 1282 emergency. It would have been worse for obvious reasons if the plane had suddenly depressurized while over the Pacific. And the “explosive decompression” forces would have been far more destructive if the plane had been at cruising altitude rather than still in its climb.
Again to oversimplify, the higher an airplane goes, the thinner and colder the air outside it is—and the longer it would take it to get down in an emergency. You can hear the urgency in the pilot’s voice about descending as fast as possible from 16,000 feet to below 10,000. Just imagine if she had been checking in from 32,000 feet—facing a much longer descent, through much colder air, after a much greater explosive force of decompression within the cabin. I’m not taking the time to run all the pressure-and-temperature calculations now, but it could have been the difference between an emergency and a disaster.
And at cruising altitude the seat belt sign would probably have been turned off, with nothing to hold some passengers and crew in place.