737 Max: Loose Rudder-Control Fastener Issue.
Let he who has never lost track of car keys cast the first stone.
This may turn on the curve of experience.
1) On the first few times the task is new and everyone is on edge to check everything.
2) Then there is the dangerous period, where some are thinking "I've got this" and they don't.
3) This is followed by the long term, where the repetition is such that missing a task practically makes people itch; they don't even have to consciously be aware, they just have a built in reflex to know they missed something and to turn around and look.
Since this door is installed and then removed and then reinstalled, but everyone knows it won't really be used, there is a good slot for the second state to happen.
I'd like to be looking at the procedures and sign-offs that go along with that re-install. Like, is there a re-install checklist taped to the door with a list of all fasteners that need to be put in, like a more sophisticated tag-out operation when servicing a machine. And a placard permanently on the door that the door shall not be removed without first affixing the checklist.
This may turn on the curve of experience.
1) On the first few times the task is new and everyone is on edge to check everything.
2) Then there is the dangerous period, where some are thinking "I've got this" and they don't.
3) This is followed by the long term, where the repetition is such that missing a task practically makes people itch; they don't even have to consciously be aware, they just have a built in reflex to know they missed something and to turn around and look.
Since this door is installed and then removed and then reinstalled, but everyone knows it won't really be used, there is a good slot for the second state to happen.
I'd like to be looking at the procedures and sign-offs that go along with that re-install. Like, is there a re-install checklist taped to the door with a list of all fasteners that need to be put in, like a more sophisticated tag-out operation when servicing a machine. And a placard permanently on the door that the door shall not be removed without first affixing the checklist.
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Should be a fundamental part of basic attitudes to safety
Boring seems to have lost focus on the importance of engineering quality. Without that, zero profit can be made.
The recommended compliance date is 10 January 2024.
The media is playing the 'Max bad, Max evil' narrative again. Since the MOM was published, the original operator has inspected the remaining 110+ aircraft in its fleet with zero findings, my airline has inspected 17 of our Max-8s (half the Max fleet) with zero findings, and this very washer and nut combination is checked as a component of every C-Check, meaning the vast majority of flying aircraft will have already had this checked as part of routine maintenance and this is just the normal 'out of abundance of caution' that we've been used to. I'd also point out, from the memo we got: "The rudder will no longer respond to pilot pedal inputs and will center relative to the current rudder trim neutral position. Rudder trim control and yaw damping will be available and function normally. Pilot response to this failure includes executing the Jammed or Restricted Flight Controls NNC." So bad that the rudder won't respond, but good that we already have an existing and well-trained (at my spot) NNC. Granted, I'd hope that if this were to happen, I hope the wind is right down the pipe or nil and that it doesn't decide to separate at VR.
I'm not suggesting that a missing nut and washer are not problematic and that we should not be concerned as pilots when manufacturing defects are found. Quite the opposite. Our professionalism should have us looking closely at the issue and thinking aloud what our actions would be should we encounter the fault. This is why I am angry about the MCAS issue - we were not advised of the potential for the fault and, by extension, could not talk about what our actions would be, despite there being an existing NNC. But the media running to the hills screaming every time a Max MOM or AD is put out is getting a little old, especially when procedures exist that help us control the potential fault. Save for two horrific flights, it has an otherwise seemingly impeccable safety record (knocking on wood right now).
The media is playing the 'Max bad, Max evil' narrative again. Since the MOM was published, the original operator has inspected the remaining 110+ aircraft in its fleet with zero findings, my airline has inspected 17 of our Max-8s (half the Max fleet) with zero findings, and this very washer and nut combination is checked as a component of every C-Check, meaning the vast majority of flying aircraft will have already had this checked as part of routine maintenance and this is just the normal 'out of abundance of caution' that we've been used to. I'd also point out, from the memo we got: "The rudder will no longer respond to pilot pedal inputs and will center relative to the current rudder trim neutral position. Rudder trim control and yaw damping will be available and function normally. Pilot response to this failure includes executing the Jammed or Restricted Flight Controls NNC." So bad that the rudder won't respond, but good that we already have an existing and well-trained (at my spot) NNC. Granted, I'd hope that if this were to happen, I hope the wind is right down the pipe or nil and that it doesn't decide to separate at VR.
I'm not suggesting that a missing nut and washer are not problematic and that we should not be concerned as pilots when manufacturing defects are found. Quite the opposite. Our professionalism should have us looking closely at the issue and thinking aloud what our actions would be should we encounter the fault. This is why I am angry about the MCAS issue - we were not advised of the potential for the fault and, by extension, could not talk about what our actions would be, despite there being an existing NNC. But the media running to the hills screaming every time a Max MOM or AD is put out is getting a little old, especially when procedures exist that help us control the potential fault. Save for two horrific flights, it has an otherwise seemingly impeccable safety record (knocking on wood right now).
Off course if you discount the two fatal crashes and other safety issues this aircraft has had in its vast 7 years service life (almost 2 of which were spent grounded) its got an impeccable safety record...
I believe they do - or should do it. But on my "Human factors in maintenance" lectures, I am telling students that there is 10% chance that duplicate inspection will not catch the fault - this comes from serious research. Hovewer, in this case, there must be more systemic problem, as there was not one-off problem, but was repeated. I agree somewhat that media is jumping up on MAX excessivelly - we do not need that each SB or even AD is trumpeted all over. (Eventhough Boeing management somewhat deserves it for what they did.) Just look on FAA or EASA website for AD issued against each type - there are hundreds and I do not need to read about each one in the media. And this is not the first time I heard about such problem. I am well aware of an instance where brand new helicopter from well known manufacturer produced intermitent chip light in main transmission - only to discover that "chip" was actually a nut that fell off from somewhere inside the transmission.
I believe they do - or should do it. But on my "Human factors in maintenance" lectures, I am telling students that there is 10% chance that duplicate inspection will not catch the fault - this comes from serious research. Hovewer, in this case, there must be more systemic problem, as there was not one-off problem, but was repeated. I agree somewhat that media is jumping up on MAX excessivelly - we do not need that each SB or even AD is trumpeted all over. (Eventhough Boeing management somewhat deserves it for what they did.) Just look on FAA or EASA website for AD issued against each type - there are hundreds and I do not need to read about each one in the media. And this is not the first time I heard about such problem. I am well aware of an instance where brand new helicopter from well known manufacturer produced intermitent chip light in main transmission - only to discover that "chip" was actually a nut that fell off from somewhere inside the transmission.
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Please read the first post in this thread. This thread is not about the Alaska Airlines plug/door, it is about bolts.
The thread about the Alaska Airlines plug/door, and the 737 issue surrounding it, is here: Alaska Airlines 737-900 MAX loses a door in-flight out of PDX
The thread about the Alaska Airlines plug/door, and the 737 issue surrounding it, is here: Alaska Airlines 737-900 MAX loses a door in-flight out of PDX
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I am going to fly a $30,000 C-150 if the weather clears for an hour of fun and all the nuts are safety-wired and get checked by an A&P every 100 hours. Is this too much to ask for Boeing to do? WTF?
* in my previous career of being an "A&P+Avionics" guy on yachts, once I found ONE thing done that badly we would tear into everything to see what else had got screwed up by an obviously incompetent builder or previous firm.
* in my previous career of being an "A&P+Avionics" guy on yachts, once I found ONE thing done that badly we would tear into everything to see what else had got screwed up by an obviously incompetent builder or previous firm.
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It’s all about the culture of the organisation. Yes, a mistake was made by someone. This applies to the plug door issue as well, obviously. Was that (the mistake) because of work pressure, arrogance, incompetence, fatigue, issues at home or any other of a myriad of reasons? We all make mistakes, I certainly have in my 30 year flying career and I know nobody sets out to make a mistake. We all want to do the best job possible but external factors can prevent that.
My concern about Boeing is that there seems to be a disconnect between what they say and what they do. I know that there are thousands of Boeing employees that work tirelessly to ensure that everything is as it should be but recently I get the impression that other factors are at work.
I read here and in the Seattle Times, about the engine anti-ice issues with the Max, that they applied for an alleviation to certification rules to allow certification with an AD (airworthiness directive) in place.
If this is true I will be horrified and appalled. I think that an organisation that claims to have moved on and learnt lessons from previous incidents should understand how ridiculous their strategy appears to the outside world.
My concern about Boeing is that there seems to be a disconnect between what they say and what they do. I know that there are thousands of Boeing employees that work tirelessly to ensure that everything is as it should be but recently I get the impression that other factors are at work.
I read here and in the Seattle Times, about the engine anti-ice issues with the Max, that they applied for an alleviation to certification rules to allow certification with an AD (airworthiness directive) in place.
If this is true I will be horrified and appalled. I think that an organisation that claims to have moved on and learnt lessons from previous incidents should understand how ridiculous their strategy appears to the outside world.
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That requirement was introduced into 14 CFR 25.607 at Amdt 25-23 in August 1970.
BOEING HAS BEEN GRANTED AN EXCEPTION TO THIS REQUIREMENT ON 737NG and 737MAX. ‘Grandfathering/Changed Product Rule’ at it’s finest.
The fastener has a 1/4” UNF-28 stiff nut.
All clear as day in the TCDS.
I’ll let you draw your own conclusions about the mindset at Boeing.
Airplanes are complicated to build, especially with composite structures and computerized systems. But tightening bolts and then having a QC process to make sure it happened is manufacturing 101. This is a failure of the most basic manufacturing processes.
The recent plug door failure now seems most likely to the failure to ensure 4 bolts were in place and properly tightened.
The steady drip drip of QC escapes in the 737, 767, and 787 lines isn’t getting better. Boeing seems to be sleep walking to catastrophe
The recent plug door failure now seems most likely to the failure to ensure 4 bolts were in place and properly tightened.
The steady drip drip of QC escapes in the 737, 767, and 787 lines isn’t getting better. Boeing seems to be sleep walking to catastrophe
I'm always looking for good examples where 'obvious' control measures are not as good as people expect: could you give me a pointer/link to the relevant research providing evidence that "there is 10% chance that duplicate inspection will not catch the fault"
Certification of work accomplished by another person
In this occurrence, the rudder cable guide tube replacement and the installation of the rudder cables were performed by individuals other than the person certifying the work. The ACA holder who certified the work was not present during the performance of the work and was not aware of the guide tube replacement before certifying the work. Even though it is possible to inspect most of the work after it has been completed, there are some aspects of the rudder cable installation that may be difficult to validate due to their location on the aircraft, especially when the person certifying the work is not aware of the work performed on the system.
For the steps that are difficult or impossible to validate once the work is completed, it may be necessary for the person signing the maintenance release for the certification of the work, to observe the work being completed, to the extent necessary to ensure the work meets the applicable standards of airworthiness.
Finding as to a risk
If the person signing a maintenance release for work accomplished by another person does not observe the work to the extent necessary to ensure that it is performed in accordance with the applicable standards of airworthiness, there is a risk that the aircraft will not be airworthy when it is returned to service.
In this occurrence, the rudder cable guide tube replacement and the installation of the rudder cables were performed by individuals other than the person certifying the work. The ACA holder who certified the work was not present during the performance of the work and was not aware of the guide tube replacement before certifying the work. Even though it is possible to inspect most of the work after it has been completed, there are some aspects of the rudder cable installation that may be difficult to validate due to their location on the aircraft, especially when the person certifying the work is not aware of the work performed on the system.
For the steps that are difficult or impossible to validate once the work is completed, it may be necessary for the person signing the maintenance release for the certification of the work, to observe the work being completed, to the extent necessary to ensure the work meets the applicable standards of airworthiness.
Finding as to a risk
If the person signing a maintenance release for work accomplished by another person does not observe the work to the extent necessary to ensure that it is performed in accordance with the applicable standards of airworthiness, there is a risk that the aircraft will not be airworthy when it is returned to service.
Here is a report just released. Take off crash of a DA42 because rudder control was reversed. Finding,
https://www.tsb.gc.ca/eng/rapports-r...0/a22o0060.pdf
https://www.tsb.gc.ca/eng/rapports-r...0/a22o0060.pdf
etc endorsement is what has pushed Boeing into dunce's corner. Until they they develop a new generation greenfield design (big bucks) Airbus will continue to increase their market share and deservedly so.
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The danger of a discussion like this is that it quickly degenerates into tribal loyalties - in this case Airbus v Boeing. Full disclosure - I am an Airbus pilot and have been for the last 22 years. I had the opportunity to fly the 737 at the time and chose Airbus - just personal preference. Trying to stand back from this and take the big picture is hard as we do not have all the facts. What I do know as a Brit is that when the de Havilland Comet had 2 fatal crashes in the 1950's, the UK commercial jet market was destroyed just about overnight and Boeing won the world with the 707. Clearly vested interests came into play, but the undeniable fact was that square windows rather than round ones caused metal fatigue failures resulting in the loss of many lives. It got fixed, but no one wanted the revised product. The rest, as they say, is history.
Move now to the 737 MAX, which has had two fatal crashes caused by Boeing's failures at many levels - not least of which was to not tell the pilots that flew them about the existence of a critical safety feature in the form of MCAS. It also transpired that to save money it was only connected to one of three possible systems - something Airbus had had in place from the beginning back in the 80s. My observation would be that, rather than humbly deal with the issue, much very unhelpful talk has taken place within the US about how, 'this is all about terrible African pilots' and 'us Americans would never have that'. Rather than just say, 'we blew it' and just get on and sort it, some of the political rhetoric from uninformed people has been nothing short of embarrassing to an industry that should be above all that. That said, it transpired that Airbus's stall recovery training was woefully inadequate, as I discovered when I did my type rating back in 2001. The training at the time was not far from, 'Don't worry - the Airbus does not stall' and we moved on. This lack of adequate training and suitably qualified simulators contributed hugely to the Air France 447 A330 accident in 2009 and the Indonesia AirAsia Flight 8501 A320 accident in 2014. Therefore Airbus has to have some degree of humility here - as I think they do. Most Airbus pilots who have been on the type for many years will have observed radical changes in training from when they first did the type rating to what happens now in both initial and recurrent training. Airbus has also been very fortunate not to lose aircraft under similar circumstances and, frankly, got lucky when the AoA probes froze up on a couple of occasions.
However, it is the 737 MAX that is in the glaring light of publicity right now and the optics are not good. Two fatal crashes and now a terrible bit of manufacturing/maintenance that should simply never have happened. The Airbus A320 Series NEO is already a mature product that requires virtually no extra training from a regular A320 CEO. It has been a seamless success in terms of entry into service. Unless Boeing do something very quickly to sort this mess out and restore confidence, their 737 MAX is well on the way to suffering the same fate as the Comet. Time is not on their side to do so.
Move now to the 737 MAX, which has had two fatal crashes caused by Boeing's failures at many levels - not least of which was to not tell the pilots that flew them about the existence of a critical safety feature in the form of MCAS. It also transpired that to save money it was only connected to one of three possible systems - something Airbus had had in place from the beginning back in the 80s. My observation would be that, rather than humbly deal with the issue, much very unhelpful talk has taken place within the US about how, 'this is all about terrible African pilots' and 'us Americans would never have that'. Rather than just say, 'we blew it' and just get on and sort it, some of the political rhetoric from uninformed people has been nothing short of embarrassing to an industry that should be above all that. That said, it transpired that Airbus's stall recovery training was woefully inadequate, as I discovered when I did my type rating back in 2001. The training at the time was not far from, 'Don't worry - the Airbus does not stall' and we moved on. This lack of adequate training and suitably qualified simulators contributed hugely to the Air France 447 A330 accident in 2009 and the Indonesia AirAsia Flight 8501 A320 accident in 2014. Therefore Airbus has to have some degree of humility here - as I think they do. Most Airbus pilots who have been on the type for many years will have observed radical changes in training from when they first did the type rating to what happens now in both initial and recurrent training. Airbus has also been very fortunate not to lose aircraft under similar circumstances and, frankly, got lucky when the AoA probes froze up on a couple of occasions.
However, it is the 737 MAX that is in the glaring light of publicity right now and the optics are not good. Two fatal crashes and now a terrible bit of manufacturing/maintenance that should simply never have happened. The Airbus A320 Series NEO is already a mature product that requires virtually no extra training from a regular A320 CEO. It has been a seamless success in terms of entry into service. Unless Boeing do something very quickly to sort this mess out and restore confidence, their 737 MAX is well on the way to suffering the same fate as the Comet. Time is not on their side to do so.
Airbus is not without fault. They knew well before the AirFrance accident that the pitot anti ice system was inadequate and could lead to serious consequences yet failed to address the issue in a timely manner.
I personally prefer the 737's that I fly to remain in one piece, but perhaps Southwest pilots are more tolerant than I am regarding minor annoyances such as doors falling from their aircraft or primary flight controls becoming unusable due to loose bolts. (I don't believe that for a second, though.)
I would merely suggest, that as an intimate companion of multiple SWA pilots, they never had a 737 max issue that scared them, and they were trained in the sim for a trim runaway related to an AOA sensor failure.
Nobody died over here…..
Nobody died over here…..