737NGs have cracked 'pickle forks' after finding several in the jets.
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One would be amazed at just how good the crews are- and do similar work almost anywhere in the world under extreme conditions.
In the late 40's and ealy 50's when douglas was top dog in commercial- Douglas proudly had the absolute best equivalent to an AOG crew and parts. Boeing at that time had the when you drive it off the lot ,its yours,- have a nice day.
But with the advent of the 707, Boeing finally realized that that attitude would not help sales, The result was to set up the current Boeing AOG system. Douglas cut theirs for cost savings and outrageous charges, the rest is history...
Last edited by Grebe; 9th Oct 2019 at 23:07. Reason: fat fingers
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Leehams is reporting today that the incidence is 5% over the first 500 inspected. https://leehamnews.com/2019/10/08/bo...-2/#more-31313
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Gol airlines in Brazil just reported 11 more. They have a fleet of 125 - many of them too new to have been inspected. Even in the unlikely event that they inspected everything, that’s 8.8%. So my guess is that the 5% number from today is significantly too low.
I can’t post links because this is my first post, but you can see the specific planes in the fleet if you search for Gol airlines on planespotters dot net. Their fleet looks like a roughly 80/20 mix of 737-800s and 700s.
I can’t post links because this is my first post, but you can see the specific planes in the fleet if you search for Gol airlines on planespotters dot net. Their fleet looks like a roughly 80/20 mix of 737-800s and 700s.
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According to the news, the ac the FA wanted checked were 165 of SW aircraft.
Yes, it does appear to be the -700 variant.
Now GOL has grounded 11.
In govt testing, there is typically a validation sample size, it will be interesting if the sample size positives, warrant further testing.
Will be interesting to see how many WJ and UA ground...
Given the cost, (well, with no repair options in the AD, and none from BA,) and anticipated retirements, wonder how many will be written off.
I have not seen a -700 BCF program like the -800.
Yes, it does appear to be the -700 variant.
Now GOL has grounded 11.
In govt testing, there is typically a validation sample size, it will be interesting if the sample size positives, warrant further testing.
Will be interesting to see how many WJ and UA ground...
Given the cost, (well, with no repair options in the AD, and none from BA,) and anticipated retirements, wonder how many will be written off.
I have not seen a -700 BCF program like the -800.
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That the SW -700s may have been some of the earliest US aircraft inspected made me wonder..... How common are these parts between NG (and perhaps classic, original, and MAX) models? Ie, if it's the same PN for all the NG aircraft, and the -700 is one of the lighter NG variants, one might expect to find relatively more cracks, all else being equal, on the heavier variants like the -800 and -900...
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An interesting data point: as of yesterday Southwest found only two jets with cracked pickle forks. They have some of the oldest 737NGs (being the launch customer for the 737-700, many of which were slated to be retired this year) -- and presumably inspected their oldest aircraft first to comply with the AD's 7-day limit.
Even more curious since the Jet Airways being modified by Boeing (possibly for Prime) and the original culprits were 800s?
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I said it was a simple description- yes there are bucu other things involved- most figured out ahead of time by the AOG crew for major items to be disconnected, removed, etc. Then an experienced crew will notyonly document each step, but most likely find other items not planned.
One would be amazed at just how good the crews are- and do similar work almost anywhere in the world under extreme conditions.
In the late 40's and ealy 50's when douglas was top dog in commercial- Douglas proudly had the absolute best equivalent to an AOG crew and parts. Boeing at that time had the when you drive it off the lot ,its yours,- have a nice day.
But with the advent of the 707, Boeing finally realized that that attitude would not help sales, The result was to set up the current Boeing AOG system. Douglas cut theirs for cost savings and outrageous charges, the rest is history...
One would be amazed at just how good the crews are- and do similar work almost anywhere in the world under extreme conditions.
In the late 40's and ealy 50's when douglas was top dog in commercial- Douglas proudly had the absolute best equivalent to an AOG crew and parts. Boeing at that time had the when you drive it off the lot ,its yours,- have a nice day.
But with the advent of the 707, Boeing finally realized that that attitude would not help sales, The result was to set up the current Boeing AOG system. Douglas cut theirs for cost savings and outrageous charges, the rest is history...
https://aviation-safety.net/database...?id=19751216-0
And look up the pics
https://aviation-safety.net/photo/63...47-246B-JA8122
it was repaired and put back in service
Depending upon how many were inspected, that's an interesting stat for two reasons - the airframes with the most likely number of high cycles seems pretty clean. As I understand from SW, the 700s mostly stayed with the blended winglets, more of the 800 series were converted to the split.
Even more curious since the Jet Airways being modified by Boeing (possibly for Prime) and the original culprits were 800s?
Even more curious since the Jet Airways being modified by Boeing (possibly for Prime) and the original culprits were 800s?
If the change in manufacturing process is a factor, one would expect the older aircraft to show few problems.
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There had been comments earlier that the pickle fork manufacturing process had been changed, with the newer method no longer hogging the piece out of a block of aluminum, but rather starting with a preformed part.
If the change in manufacturing process is a factor, one would expect the older aircraft to show few problems.
If the change in manufacturing process is a factor, one would expect the older aircraft to show few problems.
Check again on source
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Even at its its worst the effect of winglets on the root moment of the wing is very minor. Lift equals weight is the main factor. At the tip of the wing winglets can have a relatively large effect on the structure but that is it.
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Yes, wing lift distribution affects the max bending moment but it does not affect the loads transfered to the fuselage. The total lift is not affected by the distribution. What might cause a slight difference is the larger displacements caused by larger moment but as a guess that is not the first concern.
you are right in that the "Shear Loads" must be the same, as the weight inboard of the wing-root is the same, so the wings have to lift the same weight, however the bending moment going into the fuselage is increase, because the lift is further outboard. So the combination of loads going into the fuselage changes. These forks look like they "Predominantly" take vertical load, but the load transfer in this part of an aircraft is extremely complex and different loads combine in different ways, all depending on the various component stiffness.
Maximum loads and fatigue loads will have changed by a different factor or %, this looks like fatigue and I'd expect the fatigue loads to increase by a higher % that the static cases when putting a large winglet on the end of the tip
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The effect on the fuselage comes from slightly different angular didplacement at the wing root. Pickle fork is not really ment to transfer these resulting loads as the ribs in place are not ment to carry the loads but to bend and not break.
This a secondary load effect and while sometimes problematic not_too_stiff structures carry them. Make everything stiff and one has problems with them. In optimised structures strength and stiffness must both be handled.
This a secondary load effect and while sometimes problematic not_too_stiff structures carry them. Make everything stiff and one has problems with them. In optimised structures strength and stiffness must both be handled.
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Bjorn has a good update on where the cracks have been found and some collateral damage potential. Initial repair line at Victorville.
https://leehamnews.com/2019/10/08/bo...pickle-part-2/
https://leehamnews.com/2019/10/08/bo...pickle-part-2/
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The Boeing patent seen has a suggested replacement structure that would solve this problem. Think pickle fork as a previous generation solution.
Another way to think this is to treat the displacement as irresistible (it practically is) and design around it. The easiest way to do it is to make the rib at that station more flexible.
Another way to think this is to treat the displacement as irresistible (it practically is) and design around it. The easiest way to do it is to make the rib at that station more flexible.
From another site, posted yesterday. Bloomberg is reporting 36 out of 686 now. So 5.25%.
https://www.bloomberg.com/news/articles/2019-10-09/cracks-found-on-more-than-5-of-older-boeing-737s-in-inspections
https://www.bloomberg.com/news/articles/2019-10-09/cracks-found-on-more-than-5-of-older-boeing-737s-in-inspections
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My guess is that Gol inspected primarily 800s, while Southwest inspected primarily 700s so far.
Gol grounded 11 out of their fleet of 115. So just under 10% so far. And it's highly unlikely they inspected them all because many of their planes are less than 7 years old. That number will probably go up as they continue inspecting.
Gol flies mostly 800 series - I count 91 800s and 24 700s.
The Southwest fleet is mostly 700s. They have 207 800s, but I'm guessing they started by inspecting the older 700s.
There have been 5,104 800 series jets produced vs only 1,164 700 series. If this is primarily an 800 problem, that's bad for Boeing.
Southwest might just get winged by this - they have plenty of 700s. Ryanair, which flies almost exclusively 800s, could see big losses - even if their fleet is new enough to have no cracks(unlikely), the book value of their fleet (which they borrow against) would plummet.
One interesting fact: Boeing's weight in the Dow Jones is 9.65%. Far and away more than any other company. If Boeing gets wrecked by this, the economy gets hit hard.
Gol grounded 11 out of their fleet of 115. So just under 10% so far. And it's highly unlikely they inspected them all because many of their planes are less than 7 years old. That number will probably go up as they continue inspecting.
Gol flies mostly 800 series - I count 91 800s and 24 700s.
The Southwest fleet is mostly 700s. They have 207 800s, but I'm guessing they started by inspecting the older 700s.
There have been 5,104 800 series jets produced vs only 1,164 700 series. If this is primarily an 800 problem, that's bad for Boeing.
Southwest might just get winged by this - they have plenty of 700s. Ryanair, which flies almost exclusively 800s, could see big losses - even if their fleet is new enough to have no cracks(unlikely), the book value of their fleet (which they borrow against) would plummet.
One interesting fact: Boeing's weight in the Dow Jones is 9.65%. Far and away more than any other company. If Boeing gets wrecked by this, the economy gets hit hard.
Last edited by nerf; 10th Oct 2019 at 18:31.
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count now 38 and rising.
Cracks found in 38 of 800 Boeing 737 NG jets inspected globally
Boeing Co said Thursday that airlines had inspected 810 of the company's 737 NG jets around the world, and found 38 structural cracks requiring repair and replacement.
Boeing and airline officials say the planes will be grounded until repairs are made
Thomson Reuters · Posted: Oct 10, 2019 12:54 PM ET Last Updated: 3 hours ago https://www.cbc.ca/news/business/boe...316394?cmp=rss
I don't know that I would be trusting Boeing's numbers.