6 ms·

They've had calipers for literally thousands of years. I used to be involved in some intermediate gunsmithing work, and we had these tools called 'dial caliper

They've had calipers for literally thousands of years. I used to be involved in some intermediate gunsmithing work, and we had these tools called 'dial calipers' which have a little gauge you read and you can measure extremely precise things. We used it for getting cylinder diameters or clearances that needed that degree of precision. I can only imagine that in aviation, there are even more advanced tools, especially with a well-respected corp like Boeing. I would think also, that when there are these clearance issues in parts, part of the concern that makes it worth raising flags over is the fact that it's consistently off amongst different aircraft. If someone were to bring me a rifle that had some important gas clearance off, I wouldn't be that concerned, just do the work and get it back in the field, but if guys are bringing me the same rifle with the same issue over and over, it makes me really uneasy because it's inefficient for my shop, and it points to carelessness from the vendor, which raises suspicion when dealing with orthogonal issues from the same vendor. If these flapper bushings are bad consistently, and they had a spec and didn't meet it, what other corners did they cut? Just my two cents. I don't know shit about aviation, but I can appreciate the systemic concern.

CaptainZapp 6y ago
Boeing used to be a well respected company. At least until the merger with McDonnell Douglas, which turned it from an engineering driven company to a financial engineering company.
- kitteh 6y ago
  Eh there were several phases of stupidity there. 757 to replace the 727 when the 727 was doing quite fine. That said the 757 is a great plane and proved out well, just had a high price tag that really held it back. The delay and screwing around with getting the 767 out there for fear it would mess with 747 sales. Let airbus get ahead with wide-bodies and took longer than expected to get the ER variants out. Post McDonnell Dougals: The handling of the 717 (basically shutting it down when there was demand). Could have had an impact if they wanted to bring it to the regional space (to go against the crj900+ and EMB ejets). Oh so much in the planning and execution of the 787. The continued extending of the 737 well beyond what it should be (see the 900, the MAX).
- dingaling 6y ago
  And in turn the same had happened with Douglas; McDonnell's investment was reluctantly accepted in order to save the company but utterly changed the culture from engineering to finance.
LittlePeter 6y ago
I really struggle to understand how you could have used the term "well-respected" here. It ain't muscle memory, this was done deliberately. Could you explain how you can refer to Boeing being well-respected after the 737 MAX fiasco? Maybe I am missing something. [edit] remove a word
- mberning 6y ago
  They are a respected company with many respected products, despite your personal feelings towards them. They did screw up big time with the 737 MAX, but they still have a huge portfolio of well engineered products and will surely launch more well respected products in the future.
  - redis_mlc 6y ago
    > They are a respected company with many respected products, despite your personal feelings towards them. They did screw up big time with the 737 MAX, but they still have a huge portfolio of well engineered products and will surely launch more well respected products in the future. No. All of their recent models have had serious issues. The 787 was also a death trap with Li battery fires and wing root cracking. They outsourced fuselage construction to Spirit - a huge red flag for aerospace.
  - LittlePeter 6y ago
    In my opinion, a big screw up at least warrants that you lose respect, at least temporarily. They can regain respect by building new good products. Or by admitting mistakes, surely not by laying blame on the pilots. I am less forgiving. If you want to forgive them, that's your choice.
  - dingaling 6y ago
    > they still have a huge portfolio of well engineered products Mostly obtained by acquisitions. In current production only the 737, 747, 777 and 787 and T-7 originate solely from Boeing.
- TallGuyShort 6y ago
throwaway0a5e 6y ago
This is basically the FAA putting everyone on notice by saying "yo, we found a few that were real bad so y'all gotta make sure you check yours real good." It's a bushing on a control surface, of course it wears over the course of normal use. If it sat for months and corroded slightly the corrosion would cause it to wear faster. This is all perfectly normal. These things are meant to fly so the engineering more often favors dainty little parts that can barely do the job with maintenance tacked on over heavier overbuilt parts that you don't need to check as much. >I can only imagine that in aviation, there are even more advanced tools, especially with a well-respected corp like Boeing. Lol. "More advanced" often being something a long the lines of a $100000 dollar go-nogo gauge because you don't trust your employees to read a measuring tool. >If these flapper bushings are bad consistently, Bushings are probably (i.e. "almost certainly" but I wasn't in that engineering meeting so I don't know for sure) a wear item and of course they could build beefy ones but the OEM has to balance between weight and maintenance hours. Doesn't surprise me that a little extra corrosion grit in there makes them go out of spec fast. >if guys are bringing me the same rifle with the same issue over and over, it makes me really uneasy because it's inefficient for my shop, and it points to carelessness from the vendor The whole value proposition of a Hi-point or a Chinese pump shotgun is that the manufacturing tolerances are wide opens so that your wallet doesn't have to be.
- adenozine 6y ago
  Suffice to say, nobody in my unit was rolling out with Hi-point. Thanks for your post, you are clearly much more aware of aviation than I am, and what you've explained makes perfect sense. I could've clarified that while I wasn't in control of ordinance, I had some level of trust in those who were, as I'd expect the engineers at Boeing have some level of trust in the designs and blueprints they are working on. I'm curious to know more about the attitude that an engineer might have about their role in Boeing. It often seems that Boeing is being dragged through the mud, and rightfully so in some part due to the 737 MAX. However, I know enough to know that shit often rolls downhill, even onto those who never ate in the first place. I imagine there could be some disgruntled vibes going around in the shops, far from the boardrooms.
kube-system 6y ago
They're measuring it to ensure corrosion hasn't thrown it out of spec, right? Not that it wasn't manufactured to spec?
- adenozine 6y ago
  Excellent point, shows you how much of an engineer I'm NOT. That's probably a big point too. Surely there's some sort of chart they've made for all these parts and how fast they're allowed to decay, given some number of flight-hours?
  - kube-system 6y ago
    I believe there are procedures/checklists for placing aircraft in and out of storage which are different than those used for normal operation, because the conditions are different. It is my understanding that this directive is an additional check that would be performed during the typical storage procedures.
  - steffan 6y ago
    > given some number of flight-hours? I think the issue here is the lack of flight-hours. These parts were designed and specified for an in-use plane, not one that sits around. An airplane is an extremely expensive asset and they are typically almost constantly in service. It's very rare for one to be idled for months at a time.
- nogabebop23 6y ago
  yes - this is related to non-routine maintenance. I assume operation prevents moisture forming that can corrode. Storage for several weeks or months means this is like a more stringent used car "road worthiness" inspection.
nogabebop23 6y ago
It's not necessary to use calipers to measure these tolerances. In this case talking about clearance between two parts you just use a feeler gauge which is a calibrated thickness of metal. If the documentation says no more than X mm, you grab your X gauge and make sure it doesn't fit. It's the same if you're working on a 737 or your John Deere.
deleted 6y ago
[deleted]

CaptainZapp 6y ago

Boeing used to be a well respected company. At least until the merger with McDonnell Douglas, which turned it from an engineering driven company to a financial engineering company.

kitteh 6y ago
Eh there were several phases of stupidity there. 757 to replace the 727 when the 727 was doing quite fine. That said the 757 is a great plane and proved out well, just had a high price tag that really held it back. The delay and screwing around with getting the 767 out there for fear it would mess with 747 sales. Let airbus get ahead with wide-bodies and took longer than expected to get the ER variants out. Post McDonnell Dougals: The handling of the 717 (basically shutting it down when there was demand). Could have had an impact if they wanted to bring it to the regional space (to go against the crj900+ and EMB ejets). Oh so much in the planning and execution of the 787. The continued extending of the 737 well beyond what it should be (see the 900, the MAX).
dingaling 6y ago
And in turn the same had happened with Douglas; McDonnell's investment was reluctantly accepted in order to save the company but utterly changed the culture from engineering to finance.

LittlePeter 6y ago

I really struggle to understand how you could have used the term "well-respected" here. It ain't muscle memory, this was done deliberately. Could you explain how you can refer to Boeing being well-respected after the 737 MAX fiasco? Maybe I am missing something. [edit] remove a word

mberning 6y ago
They are a respected company with many respected products, despite your personal feelings towards them. They did screw up big time with the 737 MAX, but they still have a huge portfolio of well engineered products and will surely launch more well respected products in the future.
- redis_mlc 6y ago
  > They are a respected company with many respected products, despite your personal feelings towards them. They did screw up big time with the 737 MAX, but they still have a huge portfolio of well engineered products and will surely launch more well respected products in the future. No. All of their recent models have had serious issues. The 787 was also a death trap with Li battery fires and wing root cracking. They outsourced fuselage construction to Spirit - a huge red flag for aerospace.
- LittlePeter 6y ago
  In my opinion, a big screw up at least warrants that you lose respect, at least temporarily. They can regain respect by building new good products. Or by admitting mistakes, surely not by laying blame on the pilots. I am less forgiving. If you want to forgive them, that's your choice.
- dingaling 6y ago
  > they still have a huge portfolio of well engineered products Mostly obtained by acquisitions. In current production only the 737, 747, 777 and 787 and T-7 originate solely from Boeing.
TallGuyShort 6y ago

throwaway0a5e 6y ago

This is basically the FAA putting everyone on notice by saying "yo, we found a few that were real bad so y'all gotta make sure you check yours real good." It's a bushing on a control surface, of course it wears over the course of normal use. If it sat for months and corroded slightly the corrosion would cause it to wear faster. This is all perfectly normal. These things are meant to fly so the engineering more often favors dainty little parts that can barely do the job with maintenance tacked on over heavier overbuilt parts that you don't need to check as much. >I can only imagine that in aviation, there are even more advanced tools, especially with a well-respected corp like Boeing. Lol. "More advanced" often being something a long the lines of a $100000 dollar go-nogo gauge because you don't trust your employees to read a measuring tool. >If these flapper bushings are bad consistently, Bushings are probably (i.e. "almost certainly" but I wasn't in that engineering meeting so I don't know for sure) a wear item and of course they could build beefy ones but the OEM has to balance between weight and maintenance hours. Doesn't surprise me that a little extra corrosion grit in there makes them go out of spec fast. >if guys are bringing me the same rifle with the same issue over and over, it makes me really uneasy because it's inefficient for my shop, and it points to carelessness from the vendor The whole value proposition of a Hi-point or a Chinese pump shotgun is that the manufacturing tolerances are wide opens so that your wallet doesn't have to be.

adenozine 6y ago
Suffice to say, nobody in my unit was rolling out with Hi-point. Thanks for your post, you are clearly much more aware of aviation than I am, and what you've explained makes perfect sense. I could've clarified that while I wasn't in control of ordinance, I had some level of trust in those who were, as I'd expect the engineers at Boeing have some level of trust in the designs and blueprints they are working on. I'm curious to know more about the attitude that an engineer might have about their role in Boeing. It often seems that Boeing is being dragged through the mud, and rightfully so in some part due to the 737 MAX. However, I know enough to know that shit often rolls downhill, even onto those who never ate in the first place. I imagine there could be some disgruntled vibes going around in the shops, far from the boardrooms.

kube-system 6y ago

They're measuring it to ensure corrosion hasn't thrown it out of spec, right? Not that it wasn't manufactured to spec?

adenozine 6y ago
Excellent point, shows you how much of an engineer I'm NOT. That's probably a big point too. Surely there's some sort of chart they've made for all these parts and how fast they're allowed to decay, given some number of flight-hours?
- kube-system 6y ago
  I believe there are procedures/checklists for placing aircraft in and out of storage which are different than those used for normal operation, because the conditions are different. It is my understanding that this directive is an additional check that would be performed during the typical storage procedures.
- steffan 6y ago
  > given some number of flight-hours? I think the issue here is the lack of flight-hours. These parts were designed and specified for an in-use plane, not one that sits around. An airplane is an extremely expensive asset and they are typically almost constantly in service. It's very rare for one to be idled for months at a time.
nogabebop23 6y ago
yes - this is related to non-routine maintenance. I assume operation prevents moisture forming that can corrode. Storage for several weeks or months means this is like a more stringent used car "road worthiness" inspection.

nogabebop23 6y ago

It's not necessary to use calipers to measure these tolerances. In this case talking about clearance between two parts you just use a feeler gauge which is a calibrated thickness of metal. If the documentation says no more than X mm, you grab your X gauge and make sure it doesn't fit. It's the same if you're working on a 737 or your John Deere.

deleted 6y ago

[deleted]