aircraft passenger cabin stub beam

[Green 123]

existing repair on stub beams beneath the floor of aircraft passenger cabin is characterized as following:

"The existing repair must have removed the radius detail of the lower
inboard corner of the stub beam web"

Do you have any idea on what "radius detail" means?

 

[SWComposites]

Radius detail typically means the curved (radius) section between a web and flange.

 

[Green 123]

Radius detail typically means the curved (radius) section between a web and flange.

how is the curved section removed for repair?

 

[rb1957]

did the repair remove the lower flange of the spar ? (and replace it with a repair flange)

 

[SWComposites]

Green - where did you get this statement: "The existing repair must have removed the radius detail of the lower inboard corner of the stub beam web"?

The picture above looks like it comes from an SRM. What is the "existing repair" that you are referring to?

What are you trying to do? revise an existing repair? make an additional repair? seems like we need a lot more details.

 

[Green 123]

Green - where did you get this statement: "The existing repair must have removed the radius detail of the lower inboard corner of the stub beam web"?

The picture above looks like it comes from an SRM. What is the "existing repair" that you are referring to?

What are you trying to do? revise an existing repair? make an additional repair? seems like we need a lot more details.

the picture comes from a service bulletin regarding inspection of the stub beam under the floor of passenger compartment, for any repair on it. in accordance with the SB high frequency eddy current should be done on the stub beam and if any repair is on the stub beam, further HFEC inspection has to be done on relevant critical fasteners

 

[Green 123]

https://www.regulations.gov/document/FAA-2019-0249-0003

 

[Green 123]

the picture comes from a service bulletin regarding inspection of the stub beam under the floor of passenger compartment, for any repair on it. in accordance with the SB high frequency eddy current should be done on the stub beam and if any repair is on the stub beam, further HFEC inspection has to be done on relevant critical fasteners

https://www.regulations.gov/document/FAA-2019-0249-0003

 

[SWComposites]

Refer to page 13. I “think” the “radius detail” is the web corner radius where the angled crack starts at the lower inboard corner of the web. But its too late in the day to root thru 100+ pages to be sure.

 

[Green 123]

Refer to page 13. I “think” the “radius detail” is the web corner radius where the angled crack starts at the lower inboard corner of the web. But its too late in the day to root thru 100+ pages to be sure.

So the Boeing statement in page 62 that "the existing repair must have removed the radius detail....." means that radius of the web corner where crack originates should be zero in existing repair that is to say higher stress concentration??!!!.......please correct me if I'm wrong.

 

[SWComposites]

no, it means a portion of the original web is removed such that there is no longer a radius in the corner. that probably means the portion of the stub beam that attached to the inner longeron must be removed and replaced with repair angles/doublers. the whole point (as I understand it) is that there is a previous repair to the stub beam that removes the radius stress concentration and any cracks that previously existed.

if you have an aircraft that has an existing stub beam repair that you are attempting to inspect, then post a photo or sketch of the repaired configuration, showing all of the details.

 

[Sparweb]

Green,
There are some interesting comments inserted into that PDF.

Are you working for an operator that is maintaining aircraft beyond their LOV Limit of Validity?
Comment on page 8 indicates that you are not in compliance with 14 CFR 121.1115 and 129.115.

 

[rb1957]

apologies, but what is going on here ? The OP has a Boeing SB ... so ask Boeing what it means ! "surely" ??

and for gosh sake, don't post docs with "BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET" on them ! good grief ...

and Y, oh Y, are there comments labelled "Iranian 19.4.1402" ... this is scary stuff ... maybe I've answered my own question ??

maybe not so scary ... the s/n "3093" is operated by Air Baltic ... seriously dude, if the SB is unclear, ask Boeing.
On a quick scan it seems to say there may be cracking on these fuselage beams, based on service experience, so inspect and if cracking found, repair.
This seems to be the way Boeing does DTA ... find cracks on the fleet leaders and publish ... wow !?

 

[rb1957]

Hi again, Ok, Green, I apologize (again). I took to time to scan the doc some more. You have decided your planes are "group 4", ok. Then you've gone thru the SB striking out what doesn't seem applicable. Your question (the underline on pg 30) is "what is this Part 3 as in "meets the criteria in PART 3 in Paragraph 3.B" ? Fair op, I couldn't see (on a quick scan, I mean I'm not paid for this) what they are referring to, so a fair question to Boeing. I do wonder why your pdf edits come up with "Iranian" ??

 

[Green 123]

apologies, but what is going on here ? The OP has a Boeing SB ... so ask Boeing what it means ! "surely" ??

and for gosh sake, don't post docs with "BOEING PROPRIETARY, CONFIDENTIAL AND/OR TRADE SECRET" on them ! good grief ...

and Y, oh Y, are there comments labelled "Iranian 19.4.1402" ... this is scary stuff ... maybe I've answered my own question ??

maybe not so scary ... the s/n "3093" is operated by Air Baltic ... seriously dude, if the SB is unclear, ask Boeing.
On a quick scan it seems to say there may be cracking on these fuselage beams, based on service experience, so inspect and if cracking found, repair.
This seems to be the way Boeing does DTA ... find cracks on the fleet leaders and publish ... wow !?

The SB is incorporated by reference in FAA AD2019-14-15 and so anybody can download it from regulations.gov and it is not confidential.........

 

[Green 123]

Hi again, Ok, Green, I apologize (again). I took to time to scan the doc some more. You have decided your planes are "group 4", ok. Then you've gone thru the SB striking out what doesn't seem applicable. Your question (the underline on pg 30) is "what is this Part 3 as in "meets the criteria in PART 3 in Paragraph 3.B" ? Fair op, I couldn't see (on a quick scan, I mean I'm not paid for this) what they are referring to, so a fair question to Boeing. I do wonder why your pdf edits come up with "Iranian" ??

The SB is incorporated by reference in FAA AD2019-14-15 and so anybody can download it from regulations.gov and it is not confidential.........

 

[rb1957]

Are you trying to install this SB or is this just an exercise in understanding it ? I suspect the latter., is this for school ? where (country) is your school ? (Your profile has you in the US, but I'm still troubled by that "Iranian" in the comments.)

If you are in school I might draw attention to the ATA reference on the cover page. I don't think 5311 covers this part of the fuselage, more like 5331 or 5341.

I suspect that "PART 3" is "numeral 3" in the table of contents.

The fact that you can download something doesn't mean you're legally allowed to.

 

[Green 123]

no, it means a portion of the original web is removed such that there is no longer a radius in the corner. that probably means the portion of the stub beam that attached to the inner longeron must be removed and replaced with repair angles/doublers. the whole point (as I understand it) is that there is a previous repair to the stub beam that removes the radius stress concentration and any cracks that previously existed.

if you have an aircraft that has an existing stub beam repair that you are attempting to inspect, then post a photo or sketch of the repaired configuration, showing all of the details.

I really appreciate your help.

 

[Green 123]

Are you trying to install this SB or is this just an exercise in understanding it ? I suspect the latter., is this for school ? where (country) is your school ? (Your profile has you in the US, but I'm still troubled by that "Iranian" in the comments.)

If you are in school I might draw attention to the ATA reference on the cover page. I don't think 5311 covers this part of the fuselage, more like 5331 or 5341.

I suspect that "PART 3" is "numeral 3" in the table of contents.

The fact that you can download something doesn't mean you're legally allowed to.

I appreciate your help regarding JASC reference code

 

[WKTaylor]

I RF'ed post #8.
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Green 123... RE 737 SB... read the fine Print...

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