As just about the whole world has seen by now, an Alaska Airlines Boeing 737 MAX 9 had a major incident on January 5, 2024, whereby a deactivated mid-exit door blew out inflight. Inspections of more of these jets revealed that door plugs on some other 737 MAX 9s also weren’t properly secured, so these planes are now grounded, and Boeing is facing increased regulatory scrutiny.
Anyway, there’s an additional update here, and I’m not sure what exactly to make of this…
In this post:
Boeing 737-900ER inspections recommended
The Boeing 737 MAX 9 is based on the Boeing 737-900ER, and both versions of the aircraft have exactly the same mid-exit door. Regulators are now recommending that airlines visually inspect the mid-exit door plugs on these aircraft, to ensure that they are properly secured. Per the bulletin:
As an added layer of safety, the Federal Aviation Administration (FAA) is recommending that operators of Boeing 737-900ER aircraft visually inspect mid-exit door plugs to ensure the door is properly secured. The Boeing 737-900ER is not part of the newer MAX fleet but has the same door plug design.
As you can see, this is only a recommendation rather than a requirement, and there are no plans to ground these aircraft. Furthermore, some operators of the aircraft (which include Alaska, Delta, and United) have made it clear that they’re already voluntarily inspecting these aircraft.
How do you make sense of all of this?
I can completely understand the FAA erring on the side of caution and grounding the 737 MAX 9, given the 737 MAX’s history. But what I haven’t seen an answer to (and let me acknowledge that maybe I’m missing something) is why the 737-900ER is at less risk than the 737 MAX 9, according to regulators?
On the one hand, the 737-900ER entered service in 2007, and there hasn’t been a single major incident involving the deactivated mid-exit door. On the other hand, as the FAA states, the 737-900ER “has the same door plug design” as the 737 MAX 9.
So the 737 MAX 9 is grounded over the plug design, while the 737-900ER, which has the same exact feature, is fine to fly? Keep in mind that production of the jets even overlapped — the 737-900ER was produced all the way through 2019, while 737 MAX 9 production started in 2017, so one couldn’t even argue that there were consistent and distinct quality control issues.
I’m not saying the FAA is wrong here, and I don’t have a better solution. After all, it would seem extreme to ground a jet that has been safely flying for over 15 years.
At the same time, I’m confused that the 737 MAX 9 and 737-900ER have exactly the same door plug design, yet one jet is grounded, while the other one isn’t. Are we just assuming the 737 MAX is cursed, or what other possible explanation can we come up with?
Bottom line
The FAA is recommending that airlines visually inspect Boeing 737-900ER mid-exit doors, as they have the same setup as the 737 MAX 9, which is now grounded. It seems sensible that airlines would inspect these planes, but it’s still hard to rationalize the different treatment for the 737-900ER and 737 MAX 9, given that they have the same feature.
What do you make of this 737-900ER and 737 MAX 9 door plug situation?
I feel the design is ok since there has been no issues with the non Max planes. However along with so many other aspects of our current society, it’s ever increasingly harder to find qualified people to work who actually care.
Probably because its likely not a design issue but a recently developed manufacturing/QC one. The FAA is basically saying you might as well go check the doors just to make sure (also, if something is discovered, they might learn something more about the MAX), but they doubt there are going to be issues for the reasons you said. The issue is something developed since the last 737-900ER was made to now that calls the procedures...
Probably because its likely not a design issue but a recently developed manufacturing/QC one. The FAA is basically saying you might as well go check the doors just to make sure (also, if something is discovered, they might learn something more about the MAX), but they doubt there are going to be issues for the reasons you said. The issue is something developed since the last 737-900ER was made to now that calls the procedures and QC protocols Boeing and its subcontractors currently have in place for manufacturing the door plugs into question.
It's not necessarily a problem with the MAX itself and if they were still manufacturing 737-900ERs along with the MAXes right now, I bet the FAA would also be grounding more recently manufactured 900s as well as the MAXes
The NTSB hasn’t figured out what the source of the problem is but industry whistleblowers say it comes from the supplier in Malaysia that produces the door. Neither Spirit AeroSystems or Boeing are catching the problems. Current production and quality problems don’t mean the design is bad or that 10 plus year old planes had production problems
Due to a recent flight on I had on a Delta 737-900ER, I completely agree that this aircraft needs to be inspected, regardless of the airline. Here's why:
On Dec. 9, I was on Delta Flight 853 from Anchorage to Seattle. After de-icing on the tarmac in Anchorage, and before taxiing to the runway, the pilot announced that there was a technical issue "that prevents us from flying over water" (exact words). Also, during the...
Due to a recent flight on I had on a Delta 737-900ER, I completely agree that this aircraft needs to be inspected, regardless of the airline. Here's why:
On Dec. 9, I was on Delta Flight 853 from Anchorage to Seattle. After de-icing on the tarmac in Anchorage, and before taxiing to the runway, the pilot announced that there was a technical issue "that prevents us from flying over water" (exact words). Also, during the approximately 20 minute de-icing period, the cabin pressure kept changing, much more than is normal. I noticed it because I had to keep clearing the pressure from my ears. It definitely wasn't normal. In hindsight, this seems to indicate some sort of cabin pressurization issue. Anyway, we had to return to the gate at the terminal and everyone had to get off the plane. We waited in the terminal for about an hour while they did whatever they did with the plane. We all then re-boarded and this time we were able to depart to Seattle. The plane I was on was a Delta 737-932(ER), tail number N864DN, delivered new to Delta in August 2016. And yes, that particular plane does have the left and right door plugs aft of the wings, just like the Alaska Airlines plane. I say all this because what I experienced on that flight seems to mirror the Alaska Airlines situation, except in my case the plane was a 737-932(ER), rather than a 737 Max 9. So yes, I think it would be prudent for the FAA and airlines to examine all other aircraft that have these types of door plugs.
The cabin isn’t pressurized in the ground. They turn fans off during deicing.
Delta has already performed the FAA recommended inspection on all of their 737-900ERs. You might need to go to the doctor...
I'm flying on a Delta flight 737-900ER in April.
Can travelers insist on viewing maintenance record or report regarding this issue?
Yeah, Roxanne, just call either Ed Bastian (or his mini-me, Tim Dunn) and they’ll be happy to share all of their internal documentation with you.
Then I'd like to know the hours both pilots have flying as I'm choosing my flight. And if they were Air Force or not.
My best guess is MAX is grounded to manage public perception and confidence - most people don't even know the manufacturer of the plane they are flying let alone the model. Had to ground the MAX due to past events to manage perception but I would bet if it weren't for the past MAX failures they wouldn't be grounded right now.
My instinct – and I'll be the first to grant that this is intuition only, and might be wrong – is that we're moving into the "do something" phase on the part of the FAA, where the appearance of activity and involvement becomes more important than either solving the problem, or determining where acceptable risk tolerance lies.
When the FAA made its original announcement, they said that their only concern was "the safety of the...
My instinct – and I'll be the first to grant that this is intuition only, and might be wrong – is that we're moving into the "do something" phase on the part of the FAA, where the appearance of activity and involvement becomes more important than either solving the problem, or determining where acceptable risk tolerance lies.
When the FAA made its original announcement, they said that their only concern was "the safety of the flying public," explicitly dismissing any concerns for efficiency. While acknowledging that obviously the initial problem was a very real one (a plug blew off, after all!), it also sounds like the inspection and amelioration requirements are straightforward (again, from my possibly-naive vantage point).
Personally, I'd rather fly on a 737 MAX 9 (that has received an inspection for this issue, as well as whatever the usual processes in place are) than have my flight canceled. Obviously, it's not the FAA's job to implement my personal risk tolerance nationwide (that'd be absurd), but it does seem like it would be beneficial to publicize the steps that need to happen in order to resolve the concern sufficiently in the FAA's view.
I'm not an expert - and I'm a bit cynical on this whole door thing. So grain of salt and whatnot. It looks like a Boeing QC issue, plain and simple (e.g., we didn't secure the door latches properly or the door latches were not up to spec, which we should have found). It's possible it went back to the 737-900ER, but it's also possible that the QC problems are more recent. Given that there's...
I'm not an expert - and I'm a bit cynical on this whole door thing. So grain of salt and whatnot. It looks like a Boeing QC issue, plain and simple (e.g., we didn't secure the door latches properly or the door latches were not up to spec, which we should have found). It's possible it went back to the 737-900ER, but it's also possible that the QC problems are more recent. Given that there's never been -900ER incident and most of the fleet has gone through C-checks with airlines not reporting anything, I suspect it's more recent and not an inherent design flaw.
If the plug latch design had changed between the -900ER and Max 9, then the FAA would have had to approve the design change - which would be egg on their face again - but if it were different, they would also mean they would have no reason to ask for -900ER inspections.
So, the real problem is the NTSB and FAA have been accused as being too cozy with Boeing. So, now that there is a problem, even if it it looks from a distance as isolated and contained to Boeing QC, the FAA is going to be as aggressive as they can, inspect everything in case they missed something 15 years ago, and keep things grounded longer than they probably would need to while they 110% rule out design flaw that they should have caught a long time ago. Cover your butt.
Politically, they have no choice.
And frankly, Boeing needs some shaming until they take QC and supply chain seriously again.
I wonder if the FAA is thinking on the lines that the design of the plug has the potential to explode outwards more so than what would be random chance as it were.
Maybe it's the maintenance checks have a chance for failure or unclear instructions to follow etc so it's possible that the risk is higher than standard.
Sorry if this sounds a bit vague etc (English is my second language )
The reason I keep hearing, is because checking the doors/plugs is a part of most airlines' C-check regimen, which (for typical flight hours/pressurization cycles for a 737) would occur every 18-24months at a minimum...
...and since the last 739ER was delivered a...
The reason I keep hearing, is because checking the doors/plugs is a part of most airlines' C-check regimen, which (for typical flight hours/pressurization cycles for a 737) would occur every 18-24months at a minimum...
...and since the last 739ER was delivered a half decade ago, it means they've all been through at least 2 C-checks where the doors/bolts/hinges/etc would theoretically have been checked.
Hence not the same pressing need as a 7M9 that just came out of the factory within the last year.
In the US, a lot of the 739s are older and have gone through at least one heavy check where the door would have been inspected and quality/structural issues noticed and rectified already. UA and DL both have said they are inspecting the planes without customer impacts (overnight) and I don't think they have found issues with the non Max (for United) ones yet.
It is important to remember that there is certification for the design of the aircraft (type certificate) and also certification of the manufacturing process (production certificate). It is frequently the case that the FAA issues an Airworthiness Directive (AD) against certain serial numbers of aircraft, engines, or components because the issue/risk has to do with a temporary loss of control of quality and not a design issue. That appears to be the case here. The...
It is important to remember that there is certification for the design of the aircraft (type certificate) and also certification of the manufacturing process (production certificate). It is frequently the case that the FAA issues an Airworthiness Directive (AD) against certain serial numbers of aircraft, engines, or components because the issue/risk has to do with a temporary loss of control of quality and not a design issue. That appears to be the case here. The 900ER and the Max 9 share the same design, but they were built at different times, and if quality control gaps emerged recently, they would not impact the older 900ER.
An interesting question to ask is whether the FAA forgot that the Max8-200 could theoretically have a plugged exit door although in practice I think all airlines ordering the -200 have the door active because that’s the point of the -200.
I think the initial assumption was that it was a recent quality issue. Apparently however the FAA is investigating whether it’s a design flaw, so in this case it would make sense to inspect the earlier model.
Frankly I don’t trust anything Boeing has made in the “partnering for success” era (2010s to present)… when they are outsourcing everything and not paying suppliers enough to keep them afloat I don’t know how quality can’t be impacted.
I think the FAA has a duty to recommend it. If they force it all air travel is going to come to a screeching halt. The difference here is that the recent MAX issues may be due to faulty part manufacturing or installation which could be a recent thing…. But it’s a huge jump logically and legally to say the same design is safe in older models without at least a cursory look into it.
The production of early MAX 9 and late 900ER aircraft overlapped though… so if it is a recent quality issue, surely it would affect the newest 900ER as well…
Are you saying the 900ER and MAX were assembled on the same line?
I would think, even if production of both was overlapping for a time…they’d be on separate assembly lines and therefore not necessarily subject to same issues?
Well the Alaska plane had only been in service for two months and was fully assembled sometime in last August/September, far after the last 900ER was in 2019. 4 years is more than enough time for a QC issue to develop, especially when Spirit Aero was still going decently strong at the time the last 900ER was made. In the last six months, Boeing has had to make emergency cash infusions into Spirit just to...
Well the Alaska plane had only been in service for two months and was fully assembled sometime in last August/September, far after the last 900ER was in 2019. 4 years is more than enough time for a QC issue to develop, especially when Spirit Aero was still going decently strong at the time the last 900ER was made. In the last six months, Boeing has had to make emergency cash infusions into Spirit just to keep it afloat and to speed up the backlog of production on 737 MAX orders. This is all money Boeing should have been paying Spirit as a contractor in the first place since its clear they were trying to pay them as little as possible and get away with it.