As I understand it, there are two versions of the "9", the one for one for budget airlines has more seats so needs an additional emergency exit.  The other airlines have fewer seats, so that the extra exit is replaced by a door shaped "plug" which has a window.  This is supposed to be permanently fixed in place and from the inside looks like an ordinary window.

The incident was lucky in two respects.  The seat by the window was unoccupied, and the blowout happened when it did.  Three or four minutes later the altitude would have been much higher so the outside pressure would have been much less and passengers may have had their seat belts unfastened.

Hmm. well this just now from Reuters...

Does rather look like someone at the factory forgot something -perhaps the  threadlock or a torque wrench.

Not exactly a confidence inspiring newsflash.

https://www.reuters.com/business/aerospace-defense/no-data-captured-alaska-airlines-737-cockpit-voice-recorder-ntsb-chair-2024-01-08/

"Jan 8 (Reuters) - United Airlines (UAL.O) has found loose bolts on multiple 737 MAX 9 aircraft, it said on Monday, referring to the Boeing model grounded after a cabin panel blew off an Alaska Airlines-operated (ALK.N) plane in mid-flight Friday.

United found issues related to the installation on several panels that were being inspected following the accident, it said in a statement."

Makes one wonder what else has been cocked up that has not yet come to light.

Mike

Why would you replace a door with a "plug" though? If there is a door there then why not just leave it there as an additional emergency exit if there should ever be the need to use it? 

doors do have to be checked and maintained and that takes time and costs, Also one that is blocked by  a seat is not a useful thing - it may even  cause folk to run towards it in situation where they should be going the other way to a real exit. Far better if it does not look like a door at all and  mislead. 

Equally also far better then if it is actually attached to the plane as well of course....

  if not you may as well be held on the outside of the plane with sellotape.. but lets not give the budget airlines ideas.

Mike.

I would also lob in that the incidents and accidents that make the news are not the ones to worry about...because they're the rare ones which make them newsworthy. The most dangerous part of air travel is still, by a VERY long way, driving to the airport or - for those who like living really dangerously - walking to the airport! And part of the reason is that aviation incidents like this are extremely thoroughly investigated to root cause level, whereas a door falling off a car would just be another door falling off a car...

There's an interesting thing here about public perception, something about very obviously putting your life in someone else's hands (particularly at high altitude), I'm not sure whether it's that we completely misjudge the actual risk in those circumstances, or whether it is that in those circumstances we have a much lower tolerance of what is an acceptable risk. Probably a mixture of the two?

true, but the consequence  from that failure is also lower. If my car door starts to falls off on the M3 there is a good chance that I can get to the side and no harm will be done. Even if it does detach at full legal speed (!), it is likely to affect the car behind more than it affects me, assuming  I do not crash in surprise, and then only 1 or 2 people will be involved.

Mind you a colleague of mine was once greeted by a domestic bath tub in the middle of the motorway, then thing having dropped off the lorry in front.   Luckily he was obeying the 2 second rule and swerved and missed it.

Very few planes crash, but when they do it is spectacular. But  i agree to look at car accidents, even just the fatalities  in the same detail would be impractical.  We go further between accidents in planes, but we make far more trips in cars and sometimes make odd and perhaps rash judgements about speed or route when we have a personally interest in getting to some event or other on time,

The slightly sad and worrying  thing here is that loose screws are not some high tech hard to grasp failure mode, and in a car or any other product would just trigger a recall notice.

I wonder what kind of nut and bolt arrangement is used for the Plug?

Does it use

- Locktite (other brands are available)

- Second nut up tight against the first nut

- Split pin throught the nut and bolt arrangement

- Sping washer under nut

- Serrated washers either side of workpeice

- Lock nut with Nylon insert

People need to understand that vibration on a plane can do strange things to fixings as can the changes in pressure

Because you can sell a whole row of seats aligned with a plug bot you can't put seats aligned with a door. 
So the basic answer is it makes more profit for the airline. 
Companies exist to maximise their profits and cut every corner they can get away with to achieve that. 
Note 'get away with' is subject to laws, regulations, customer pressure, and in some cases ethics/morality

In the Max 8's there are seats next to the additional door (only two for passengers) and a jump seat for a crew member right next to the door. I had the 'pleasure' of sitting in that row recently with the crew member literally right in my face 

mapj1 said:

The slightly sad and worrying  thing here is that loose screws are not some high tech hard to grasp failure mode, and in a car or any other product would just trigger a recall notice.

In a newish car yes, but not in an older one - having had the brakes fail in my wife's car over Christmas, due to a calliper basically dropping off the car, something I'm very aware of! Whereas this incident, like all aviation incidents, will be picked over in huge detail for root causes, irrespective of the age of the vehicle. Hence I'm rather more nervous of crossing the road in front of 16 year old cars of a certain make and model than I am of flying in a 737...

(I'm not going to say what make and model as that would be unfair - could have happened in any car of that age.)

Loose screws are necessary if the airhostess is to be able to unscrew the emergency door quickly.  The H&S regulations need reviewing to be practical and safe for both crew and passengers.

Loose screws are necessary if the airhostess is to be able to unscrew the emergency door quickly.  The H&S regulations need reviewing to be practical and safe for both crew and passengers.