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mjoelnir
Posts: 9391
Joined: Sun Feb 03, 2013 11:06 pm

Re: 737NG Pickle fork issue

Fri Nov 01, 2019 12:11 pm

kalvado wrote:
benjjk wrote:
Mostly wrote:

I’m not saying it’s likely. You’re right that it hasn’t happened yet. But I doubt you’d argue that a wing connected to a cracked fork can cope with less load before it fails. So the question is how much less. And you and I don’t know the answer to that.

Could bad turbulence cause a failure? Probably not. But maybe. Could a hard landing cause a failure, probably not. But maybe. The point is that we don’t know.

We do know that cracks in parts that weren’t engineered to crack can transmit stress to areas that may not have been engineered to handle that stress, so runway failures can happen.

Don’t get me wrong, I’m not suggesting that failure is likely, what I’m saying is that we don’t have enough data to make an assessment. And the track record isn’t great so far with the manufacturing consistency of the part, so that adds to overall uncertainty.



Quick edit: the accepted safety factor for commercial aviation is 1.5 to 2.5. Boeing’s corporate culture probably means they’re on the left side of that range. So figure we’re a 1/3 drop in structural integrity away from being at a safety factory of 1.0. That’s not outside the realm of possibility


The crack does reduce the margin of safety, which is why these particular aircraft are grounded - though ferry flights are permitted. But to suggest that means a wing could fall off tomorrow is, to borrow the Qantas press release, alarmist. Put it this way: after the MAX debacle I would expect the FAA to be taking a very conservative approach to this. But even they have said the inspections can wait until a convenient time (within limits obviously), and don't need to happen right away.

One more thing: I have been told that replacement of the pickle forks takes about 3000 man-hours. With a fix that expensive, "fly until it cracks" is the only realistic avenue here, unless it's a very high-time aircraft likely to see imminent cracking.

So how much time industry had before an accident if problem wasn't noticed? My impression is not that much.
Of course, we don't know how fast crack propagates and how bad consequencies can really be. Possibly - not very likely - this is a self-limiting process to begin with. From Boeing-FAA responce, though, this seems to be a bad case of propagating crack and possible bad outcome.
As far as I understand, once the crack is initiated - a countdown timer is started, and it is a matter of time before part is weakened to the point it cannot handle the load. AD assumes few thousand cycles before that happens; lets guess 5k - that is 3 years at 5 cycles a day.
Now there are 50 planes with cracking at various stages; no data on how badly or mildly cracked different frames are. Assuming more or less uniform distribution of crack progress, the worst case could be within 5000/50=100 cycles until a failure, that is about a month of flying, and expected crash rate would be on the order of 10/year.
Maybe I am missing something, but grounding older fleet doesn't sound that crazy with such probabilities. Apparently, FAA and Boeing decided that expedite inspections is a safe enough bet. One has to remember that those are just that - estimates and bets. Boeing just lost big time on "10 months before next event" one.


For me the answer is simple. When cracks are detected, the frame is grounded until the repair is done. So no flying with a frame with detected pickel fork cracks, that means, that the cracks are taken serious.

I expect now all frames being inspected when they reach 22,600 cycles, the inspection done before the frame reaches 23,599 cycles.

After the data out of the current inspections has been collected, a inspection regime has to be set, or all pickle forks to be replaced in a certain interval, moving it from a lifetime part to a limited time part.
 
moa999
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 12:51 pm

mjoelnir wrote:
For me the answer is simple. When cracks are detected, the frame is grounded until the repair is done. So no flying with a frame with detected pickel fork cracks, that means, that the cracks are taken serious.

I expect now all frames being inspected when they reach 22,600 cycles, the inspection done before the frame reaches 23,599 cycles.


Agreed. Possibly Boeing may need to look at an alternate material or method as well.

Given its seemingly only a 1hr inspection job, I'd expect inspection will also occur for younger aircraft as part of regular maintenance,

And probability suggests they will find some cracks on aircraft under 22.6k.
 
acechip
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 2:20 pm

Question: Is it fully established that all the planes with cracks have winglets installed? I understand that the winglet added to the stress.
 
ShamrockBoi330
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 2:30 pm

acechip wrote:
Question: Is it fully established that all the planes with cracks have winglets installed? I understand that the winglet added to the stress.


I believe one of the SAS planes at least did not have winglets.

EDIT; found it further up thread, LN-RPK 737-700 was being retired, had no winglets.
 
kalvado
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 2:35 pm

mjoelnir wrote:
kalvado wrote:
benjjk wrote:

The crack does reduce the margin of safety, which is why these particular aircraft are grounded - though ferry flights are permitted. But to suggest that means a wing could fall off tomorrow is, to borrow the Qantas press release, alarmist. Put it this way: after the MAX debacle I would expect the FAA to be taking a very conservative approach to this. But even they have said the inspections can wait until a convenient time (within limits obviously), and don't need to happen right away.

One more thing: I have been told that replacement of the pickle forks takes about 3000 man-hours. With a fix that expensive, "fly until it cracks" is the only realistic avenue here, unless it's a very high-time aircraft likely to see imminent cracking.

So how much time industry had before an accident if problem wasn't noticed? My impression is not that much.
Of course, we don't know how fast crack propagates and how bad consequencies can really be. Possibly - not very likely - this is a self-limiting process to begin with. From Boeing-FAA responce, though, this seems to be a bad case of propagating crack and possible bad outcome.
As far as I understand, once the crack is initiated - a countdown timer is started, and it is a matter of time before part is weakened to the point it cannot handle the load. AD assumes few thousand cycles before that happens; lets guess 5k - that is 3 years at 5 cycles a day.
Now there are 50 planes with cracking at various stages; no data on how badly or mildly cracked different frames are. Assuming more or less uniform distribution of crack progress, the worst case could be within 5000/50=100 cycles until a failure, that is about a month of flying, and expected crash rate would be on the order of 10/year.
Maybe I am missing something, but grounding older fleet doesn't sound that crazy with such probabilities. Apparently, FAA and Boeing decided that expedite inspections is a safe enough bet. One has to remember that those are just that - estimates and bets. Boeing just lost big time on "10 months before next event" one.


For me the answer is simple. When cracks are detected, the frame is grounded until the repair is done. So no flying with a frame with detected pickel fork cracks, that means, that the cracks are taken serious.

I expect now all frames being inspected when they reach 22,600 cycles, the inspection done before the frame reaches 23,599 cycles.

After the data out of the current inspections has been collected, a inspection regime has to be set, or all pickle forks to be replaced in a certain interval, moving it from a lifetime part to a limited time part.

Your answer is an answer of an airline mechanic: I follow established procedure and will feel good about it. Nothing wrong with that, this is the way things work on the airline level. But I am trying to put myself into the shoes of an FAA/Boeing engineer putting the AD together. And my feeling is - we came uncomfortably close to an accident.
Yes, planes were flying with this crack for a while - and nothing happened. But the way such things work - at some point there is a bad day, and it suddenly goes from "nothing happened yet" to "this caused a crash". I am just trying to guesstimate how far we were from that bad day. Looks like, as I said, uncomfortably close....
 
spacecookie
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 3:29 pm

I fly regularly on a 737 , the last time was 2 flights this week. It is quite strange as a passenger when you know there can be cracks even if one plane was 6 and the other one 1.5 years old (or young) but most Of the time i are the wings flexing a lot on the ground - sometimes you are 10-15 minutes taxing exceeding 15 kts, and some taxi ways are quite bumpy

I think this could also have some influence on the stress on the wings.
 
StTim
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 3:43 pm

All planes have cracks. Mostly they are stop drilled and monitored. Repairs are done as required.

The slight difference is that there has not been cracking in the pickle forks before so it was unexpected. It is also a complex and highly stressed area so extra care must be taken.
 
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CALTECH
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 4:24 pm

Hearing there is a MOD being developed for this issue, and MCO might be doing this MOD on NGs soon. MOD will fix issue if cracks found and prevent issue if no cracks found.
You are here.
 
mjoelnir
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 4:52 pm

kalvado wrote:
mjoelnir wrote:
kalvado wrote:
So how much time industry had before an accident if problem wasn't noticed? My impression is not that much.
Of course, we don't know how fast crack propagates and how bad consequencies can really be. Possibly - not very likely - this is a self-limiting process to begin with. From Boeing-FAA responce, though, this seems to be a bad case of propagating crack and possible bad outcome.
As far as I understand, once the crack is initiated - a countdown timer is started, and it is a matter of time before part is weakened to the point it cannot handle the load. AD assumes few thousand cycles before that happens; lets guess 5k - that is 3 years at 5 cycles a day.
Now there are 50 planes with cracking at various stages; no data on how badly or mildly cracked different frames are. Assuming more or less uniform distribution of crack progress, the worst case could be within 5000/50=100 cycles until a failure, that is about a month of flying, and expected crash rate would be on the order of 10/year.
Maybe I am missing something, but grounding older fleet doesn't sound that crazy with such probabilities. Apparently, FAA and Boeing decided that expedite inspections is a safe enough bet. One has to remember that those are just that - estimates and bets. Boeing just lost big time on "10 months before next event" one.


For me the answer is simple. When cracks are detected, the frame is grounded until the repair is done. So no flying with a frame with detected pickel fork cracks, that means, that the cracks are taken serious.

I expect now all frames being inspected when they reach 22,600 cycles, the inspection done before the frame reaches 23,599 cycles.

After the data out of the current inspections has been collected, a inspection regime has to be set, or all pickle forks to be replaced in a certain interval, moving it from a lifetime part to a limited time part.

Your answer is an answer of an airline mechanic: I follow established procedure and will feel good about it. Nothing wrong with that, this is the way things work on the airline level. But I am trying to put myself into the shoes of an FAA/Boeing engineer putting the AD together. And my feeling is - we came uncomfortably close to an accident.
Yes, planes were flying with this crack for a while - and nothing happened. But the way such things work - at some point there is a bad day, and it suddenly goes from "nothing happened yet" to "this caused a crash". I am just trying to guesstimate how far we were from that bad day. Looks like, as I said, uncomfortably close....


My point was, a frame with know cracks in the pickle fork is not used until the repair is done. One does not use a frame with cracks, not for one extra cycle.
 
mjoelnir
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 4:53 pm

StTim wrote:
All planes have cracks. Mostly they are stop drilled and monitored. Repairs are done as required.

The slight difference is that there has not been cracking in the pickle forks before so it was unexpected. It is also a complex and highly stressed area so extra care must be taken.


The pickle fork was a component that was not supposed to crack.
 
kalvado
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 5:49 pm

mjoelnir wrote:
kalvado wrote:
mjoelnir wrote:

For me the answer is simple. When cracks are detected, the frame is grounded until the repair is done. So no flying with a frame with detected pickel fork cracks, that means, that the cracks are taken serious.

I expect now all frames being inspected when they reach 22,600 cycles, the inspection done before the frame reaches 23,599 cycles.

After the data out of the current inspections has been collected, a inspection regime has to be set, or all pickle forks to be replaced in a certain interval, moving it from a lifetime part to a limited time part.

Your answer is an answer of an airline mechanic: I follow established procedure and will feel good about it. Nothing wrong with that, this is the way things work on the airline level. But I am trying to put myself into the shoes of an FAA/Boeing engineer putting the AD together. And my feeling is - we came uncomfortably close to an accident.
Yes, planes were flying with this crack for a while - and nothing happened. But the way such things work - at some point there is a bad day, and it suddenly goes from "nothing happened yet" to "this caused a crash". I am just trying to guesstimate how far we were from that bad day. Looks like, as I said, uncomfortably close....


My point was, a frame with know cracks in the pickle fork is not used until the repair is done. One does not use a frame with cracks, not for one extra cycle.

Well, again - someone has to set that as a procedure. Whoever did that had alternatives - e.g. blanket grounding until inspections are done (as QF union called for - messing up with schedules big time); or going the other way and monitoring cracks after they are found while allowing some operations (in a current approach some planes will be sitting for months waiting for repairs).
Whoever chosen to run inspections the way they did - had to do risk assessment and take a calculated risk of a crash in permitting some operations of planes where cracks exist, but yet to be found.

Where this started - do we think QF union was overreacting? Apparently, AD is less restrictive; I am just trying to decide for myself which is a better option and how much risk airlines are taking. Looking at the limited data available, I would say union is conservative in their estimates - but "alarmist" is too harsh of a word.
 
djm18
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 6:04 pm

CALTECH wrote:
Hearing there is a MOD being developed for this issue, and MCO might be doing this MOD on NGs soon. MOD will fix issue if cracks found and prevent issue if no cracks found.


What is an MOD?
 
ShamrockBoi330
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 6:13 pm

QF now say 3 grounded out of 33 checked from a fleet of 75, all 3 around the 26,000 mark.

https://www.upi.com/Top_News/World-News ... 5659/?sl=2
 
oschkosch
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 6:42 pm

ShamrockBoi330 wrote:
QF now say 3 grounded out of 33 checked from a fleet of 75, all 3 around the 26,000 mark.

https://www.upi.com/Top_News/World-News ... 5659/?sl=2
so 10% of all checked planes are grounded??? Ouch!

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mjoelnir
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 8:49 pm

kalvado wrote:
mjoelnir wrote:
kalvado wrote:
Your answer is an answer of an airline mechanic: I follow established procedure and will feel good about it. Nothing wrong with that, this is the way things work on the airline level. But I am trying to put myself into the shoes of an FAA/Boeing engineer putting the AD together. And my feeling is - we came uncomfortably close to an accident.
Yes, planes were flying with this crack for a while - and nothing happened. But the way such things work - at some point there is a bad day, and it suddenly goes from "nothing happened yet" to "this caused a crash". I am just trying to guesstimate how far we were from that bad day. Looks like, as I said, uncomfortably close....


My point was, a frame with know cracks in the pickle fork is not used until the repair is done. One does not use a frame with cracks, not for one extra cycle.

Well, again - someone has to set that as a procedure. Whoever did that had alternatives - e.g. blanket grounding until inspections are done (as QF union called for - messing up with schedules big time); or going the other way and monitoring cracks after they are found while allowing some operations (in a current approach some planes will be sitting for months waiting for repairs).
Whoever chosen to run inspections the way they did - had to do risk assessment and take a calculated risk of a crash in permitting some operations of planes where cracks exist, but yet to be found.

Where this started - do we think QF union was overreacting? Apparently, AD is less restrictive; I am just trying to decide for myself which is a better option and how much risk airlines are taking. Looking at the limited data available, I would say union is conservative in their estimates - but "alarmist" is too harsh of a word.


That is actually the procedure, cracks found equals frame grounded until repaired.

The other part is when and what frames get inspected and there the AD gives a 1000 cycle time frame for frames between 22,600 cycles and 29,999 cycles. All frames over 29,999 cycles should be inspected by now.

I expect when some numbers have been collected about the frequency of cracks on what age of frames, we will see a new inspection regime.
 
smokeybandit
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 9:05 pm

What kind of cracks are we talking about here? Big ones visible to the naked eye or just small hairline cracks?

I'm not criticizing the effort, but truly what kind of risk are we talking here? Is it closer to "holy crap how did planes not crash as a result" or "it wasn't designed or tested to fly with cracks, so to be on the truly safe side, they need replaced ASAP"
 
mjoelnir
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 9:52 pm

acechip wrote:
Question: Is it fully established that all the planes with cracks have winglets installed? I understand that the winglet added to the stress.


no, some frames with cracks have no winglets. Winglets adding to the stress is just an idea put forward.
Last edited by mjoelnir on Fri Nov 01, 2019 9:55 pm, edited 1 time in total.
 
moa999
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 9:53 pm

A crack is a crack. And the place that the wing attaches to the fuselage is somewhat critical.
According to Boeing these were 90k+ cycle parts, so life of aircraft and didn't need to be inspected.
Obviously that has changed.

On the winglets question, both Korean and GOL have wingletless planes - but unsure if they are any of the aircraft with cracks.
Last edited by moa999 on Fri Nov 01, 2019 9:53 pm, edited 1 time in total.
 
mjoelnir
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Re: 737NG Pickle fork issue

Fri Nov 01, 2019 9:55 pm

smokeybandit wrote:
What kind of cracks are we talking about here? Big ones visible to the naked eye or just small hairline cracks?

I'm not criticizing the effort, but truly what kind of risk are we talking here? Is it closer to "holy crap how did planes not crash as a result" or "it wasn't designed or tested to fly with cracks, so to be on the truly safe side, they need replaced ASAP"


There Boeing engineers have to answer. As no cracks were expected, I assume nobody knows.
 
easyjet
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Re: 737NG Pickle fork issue

Sat Nov 02, 2019 7:20 am

CALTECH wrote:
djm18 wrote:
CALTECH wrote:
Hearing there is a MOD being developed for this issue, and MCO might be doing this MOD on NGs soon. MOD will fix issue if cracks found and prevent issue if no cracks found.


What is an MOD?


Modification.

The Airbus fanboys really trying to pile it on. These items weren't supposed to crack either.......Cracks Happen

https://www.federalregister.gov/documen ... -airplanes



Not sure about others, but I don't consider myself a "fanboy" of either manufacturer, perhaps a "fanboy" of safe commercial aviation. I read the first linked article and it seems that the airbus aircraft cracks were discovered as part of fatigue testing, which is the point of testing in the first place, to ensure safety. The pickle fork cracks did not occur from fatigue testing, they are not usually inspected as they are a "safe life" component, and only discovered by chance. Regardless, just because cracking is common doesn't make this situation right nor does it diminish the significance of the premature failure.
 
flymad
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 9:29 am

If the picke fork is a Boeing patent, how does Airbus handle the wing to body attachment.
 
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SQ32
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 9:50 am

Cracked at 20,000++ cycles.

The cracks surprised the industry because pickle forks are supposed to last 90,000 cycles without cracking, essentially the lifespan of an aircraft.

https://www.airlineratings.com/news/qan ... cle-737ng/

Boeing MBAs and parachuted executives must have destroyed their engineers.
 
moa999
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 9:59 am

SQ32 wrote:
Cracked at 20,000++ cycles.
.


Known days ago.
Qantas has already inspected all it's 33 aircraft with 22.6-30k cycles (well ahead of the FAAs timeline)

3 aircraft with cracks found - all at approx 27k cycles (2002/3 deliveries)
 
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SQ32
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 10:29 am

The grounded 50 planes could be tip of iceberg. Given that a non insignificant of planes failed structurelly at 20k cycle, high chance that more cases will be discovered once authorities ordered a mandatory check for every 737 NG. how about planes at 30k 40k 50k 60k 70k 80k?

Given the widespread proliferation of 737NG -- thousands of flight per day, it will be disastrous to aviation.

Image
 
moa999
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 10:41 am

They've already check everything above 30k..
Mostly planes over 20 years old.
 
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bgm
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 11:04 am

moa999 wrote:
They've already check everything above 30k..
Mostly planes over 20 years old.


Source?
 
planecane
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 11:35 am

bgm wrote:
moa999 wrote:
They've already check everything above 30k..
Mostly planes over 20 years old.


Source?

It's actually any frame over 33,500 that have been inspected because they were ordered to be done within a week several weeks ago.
 
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bgm
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 11:49 am

If Boeing was wrong with the durability of this critical 'lifetime' structural competent, should other 'lifetime' parts also be inspected?

If one of these pickle forks cracked in 2 on a flight, what would happen? Would the plan just become weakened or would it break apart?
 
asdf
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 11:52 am

bgm wrote:
If Boeing was wrong with the durability of this critical 'lifetime' structural competent, should other 'lifetime' parts also be inspected?

If one of these pickle forks cracked in 2 on a flight, what would happen? Would the plan just become weakened or would it break apart?


i guess its flight attitudes with only one wing attached would make the onward flight uncomfortable
 
mjoelnir
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 11:58 am

planecane wrote:
bgm wrote:
moa999 wrote:
They've already check everything above 30k..
Mostly planes over 20 years old.


Source?

It's actually any frame over 33,500 that have been inspected because they were ordered to be done within a week several weeks ago.


All frames over 30,000 cycles should have been inspected by now and frames between 22,600 and 29,999 cycles are being inspected.
For frames between 22,600 and 29,999 cycles the inspection has to be done inside of 1,000 cycles and prior to reaching 30,000 cycles.

http://rgl.faa.gov/Regulatory_and_Guida ... -20-02.pdf
 
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Spacepope
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 3:13 pm

SQ32 wrote:
The grounded 50 planes could be tip of iceberg. Given that a non insignificant of planes failed structurelly at 20k cycle, high chance that more cases will be discovered once authorities ordered a mandatory check for every 737 NG. how about planes at 30k 40k 50k 60k 70k 80k?

Given the widespread proliferation of 737NG -- thousands of flight per day, it will be disastrous to aviation.

Image


Calm down, the earliest Southwest -700s are only into the low 40,000s cycle-wise, I don't even think any have hot 50k.

Given the widespread proliferation of the 737NG -- there will be a statistically significant sample so actual evaluation can be done.
The last of the famous international playboys
 
889091
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 4:03 pm

so who's footing the bill to have the pickle forks replaced (including the downtime incurred)? Boeing or the airlines themselves?
 
benbeny
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 4:49 pm

Any info on P-8? Does the raked wingtip create differences?
Or they've not hit 20k cycle mark yet?
 
TUGMASTER
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 5:32 pm

benbeny wrote:
Any info on P-8? Does the raked wingtip create differences?
Or they've not hit 20k cycle mark yet?


I don’t suppose they ever will....
 
planecane
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 5:35 pm

889091 wrote:
so who's footing the bill to have the pickle forks replaced (including the downtime incurred)? Boeing or the airlines themselves?

I assume the airlines. I doubt there's an an unlimited duration warranty even on parts designed to last forever. Boeing is probably providing replacement parts at cost but not eating the whole expense.
 
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flyingclrs727
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 6:34 pm

planecane wrote:
889091 wrote:
so who's footing the bill to have the pickle forks replaced (including the downtime incurred)? Boeing or the airlines themselves?

I assume the airlines. I doubt there's an an unlimited duration warranty even on parts designed to last forever. Boeing is probably providing replacement parts at cost but not eating the whole expense.


I would assume that Boeing or the NTSB would take possession of the old parts for research purposes.
 
jetmatt777
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 8:07 pm

planecane wrote:
889091 wrote:
so who's footing the bill to have the pickle forks replaced (including the downtime incurred)? Boeing or the airlines themselves?

I assume the airlines. I doubt there's an an unlimited duration warranty even on parts designed to last forever. Boeing is probably providing replacement parts at cost but not eating the whole expense.


I'm sure airlines are footing the bill currently, but I wouldn't be surprised to see some lawyer action for damages from a product that did not work as designed. Whether or not the courts would honor it, I don't know - but I would expect some potential litigation. It's not a cheap repair.
 
mjoelnir
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 8:42 pm

I think airlines simply just have to take the costs on frames they own. Frames are far to old to fall into some warranty consideration.
On leased frames I expect the cost to fall on the leasing company.
 
INFINITI329
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 8:58 pm

mjoelnir wrote:
I think airlines simply just have to take the costs. Frames are far to old to fall into some warranty consideration.


If a part was designed to last for up 90k cycles but fails before even reaching 1/3 of its lifespan the manufacturer has a problem. Most of the NG customers with grounded frames are also MAX customers so to some save face and avoid court Boeing should reimburse these airlines for the repairs and just add it on to their MAX compensation checks.
 
kalvado
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Re: 737NG Pickle fork issue

Mon Nov 04, 2019 9:35 pm

INFINITI329 wrote:
mjoelnir wrote:
I think airlines simply just have to take the costs. Frames are far to old to fall into some warranty consideration.


If a part was designed to last for up 90k cycles but fails before even reaching 1/3 of its lifespan the manufacturer has a problem. Most of the NG customers with grounded frames are also MAX customers so to some save face and avoid court Boeing should reimburse these airlines for the repairs and just add it on to their MAX compensation checks.

Sometimes things break, its a fact. I don't expect company to maintain the product for life for free. Typical lifetime is usually longer than the warranty. Service contract or extended warranty may be offered for a fee, or whatever equivalent Boeing has.
If the part is designed to last for 90k, it doesn't mean it is guaranteed for 90k - it often would come with 15k warranty against defects of a certain type. Or maybe there is some different wording in contract.
If there is a systematic failure, then there may be assumption that entire plane is not designed to the specs as advertised and certain compensation is on order. Or maybe plane itself is warranted to a fraction of specified lifetime.
I can give you an example from the car world, where certain part designed for life of the car started to fail; owners of one model won a class action lawsuit against manufacturer - and owners of the other model with the same defect (including me) got nothing other than a suggestion to talk to regional manager about some reduced rate repair at manager's discretion.
So.. It all depends.
 
benbeny
Posts: 240
Joined: Thu Nov 03, 2016 1:44 pm

Re: 737NG Pickle fork issue

Tue Nov 05, 2019 2:15 am

TUGMASTER wrote:
benbeny wrote:
Any info on P-8? Does the raked wingtip create differences?
Or they've not hit 20k cycle mark yet?


I don’t suppose they ever will....

I think they may not fly that much, but military planes usually stay longer in service than airlines ones. Besides P-8 sometimes fly low flying mission and stay in the air for 8 hours. I wonder will they show premature crack in this area too.
 
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Nomadd
Posts: 401
Joined: Sat Dec 09, 2017 3:26 pm

Re: 737NG Pickle fork issue

Tue Nov 05, 2019 4:35 am

benbeny wrote:
TUGMASTER wrote:
benbeny wrote:
Any info on P-8? Does the raked wingtip create differences?
Or they've not hit 20k cycle mark yet?


I don’t suppose they ever will....

I think they may not fly that much, but military planes usually stay longer in service than airlines ones. Besides P-8 sometimes fly low flying mission and stay in the air for 8 hours. I wonder will they show premature crack in this area too.

It's cycles they worry about. P-8s don't take off and land six times a day.
 
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Spacepope
Posts: 4705
Joined: Tue Dec 28, 1999 11:10 am

Re: 737NG Pickle fork issue

Tue Nov 05, 2019 4:42 am

Nomadd wrote:
benbeny wrote:
TUGMASTER wrote:

I don’t suppose they ever will....

I think they may not fly that much, but military planes usually stay longer in service than airlines ones. Besides P-8 sometimes fly low flying mission and stay in the air for 8 hours. I wonder will they show premature crack in this area too.

It's cycles they worry about. P-8s don't take off and land six times a day.

Well, they kinda do. Military aircraft, when they do fly, spend a bunch of time doing touch and goes. In this case, that can be much worse than pressurization cycles.
The last of the famous international playboys
 
889091
Posts: 211
Joined: Sat Apr 06, 2019 7:56 pm

Re: 737NG Pickle fork issue

Tue Nov 05, 2019 9:11 pm

How are the wings on Boeing's other non CFRP planes mated onto the fuselage? Larger versions of the pickle forks?

Also, why didn't this problem rear its head on the Classics and Jurassics?

BCA's reputation is getting beat up pretty badly - if I were an operator with an outstanding order for the MAX having to run my fleet of NGs to the max (no pun intended) to cover the gap, then getting the news that a NG lifetime component MAY be developing cracks after only 20k+ cycles and having to pull those planes out for repairs if they indeed have cracks....doesn't bode very well for BCA at all.

I remember watching this YouTube video over and over and over again - watching in awe at what Boeing managed to produce.
https://www.youtube.com/watch?v=Ai2HmvAXcU0

How times have changed.
 
afgeneral
Posts: 136
Joined: Sat Jul 02, 2016 2:43 pm

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 9:17 am

looks like Ryanair had to ground 3 737s due to the issue
 
FB330
Posts: 111
Joined: Thu Sep 29, 2016 9:46 pm

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 10:04 am

afgeneral wrote:
looks like Ryanair had to ground 3 737s due to the issue


Indeed. Artcile here with more details.

http://www.msn.com/en-gb/news/world/boe ... ocid=ientp
 
Draken21fx
Posts: 241
Joined: Wed Jun 15, 2016 10:38 am

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 10:22 am

FB330 wrote:
afgeneral wrote:
looks like Ryanair had to ground 3 737s due to the issue


Indeed. Artcile here with more details.

http://www.msn.com/en-gb/news/world/boe ... ocid=ientp


And the original here

https://www.theguardian.com/business/2019/nov/06/boeing-737-cracks-ryanair-grounds-three-planes-due-to-cracking-between-wing-and-fuselage

I personally didnt know that Ryanair flies planes >15 years old.
 
Etheereal
Posts: 374
Joined: Tue Nov 29, 2016 11:44 am

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 3:45 pm

Ryanair bought a lot of planes after 9/11, when plane prices were at "rock bottom".

Edit: And if they arrived around 2002-2003, that will explain you why they have some "old" planes.
 
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Spacepope
Posts: 4705
Joined: Tue Dec 28, 1999 11:10 am

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 3:53 pm

Etheereal wrote:
Ryanair bought a lot of planes after 9/11, when plane prices were at "rock bottom".

Edit: And if they arrived around 2002-2003, that will explain you why they have some "old" planes.


I think what he was referring to was that Ryanair used to make money selling their used 738s after just a few years for prices higher than the screaming deal they initially paid.
The last of the famous international playboys
 
Etheereal
Posts: 374
Joined: Tue Nov 29, 2016 11:44 am

Re: 737NG Pickle fork issue

Wed Nov 06, 2019 6:03 pm

Spacepope wrote:
Etheereal wrote:
Ryanair bought a lot of planes after 9/11, when plane prices were at "rock bottom".

Edit: And if they arrived around 2002-2003, that will explain you why they have some "old" planes.


I think what he was referring to was that Ryanair used to make money selling their used 738s after just a few years for prices higher than the screaming deal they initially paid.

They were probably unable to sell most of them, so they ended up using the remaining ones.

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