UAL747-600 From United States of America, joined Sep 1999, 538 posts, RR: 0 Posted (3 years 2 months 1 week 6 days 12 hours ago) and read 10997 times:
I apologize if this has been brought up before but how long does it uaually take for Boeing to complete 787 side of body modifications. It appears that the most recent one N6066Z took almost 2 months (Jan. 12 - Mar. 9) to complete. Have all the modifications taken this long? I wonder how much longer until all that need it are completed?
Stitch From United States of America, joined Jul 2005, 26690 posts, RR: 83 Reply 1, posted (3 years 2 months 1 week 6 days 12 hours ago) and read 10965 times:
Well it depends on the frame.
Boeing have developed a design change so the new planes being built should have the fix already in place.
For those aircraft that have not yet had the wingbox attached to the fuselage, they have plenty of space to work, so those fixes do not take very long.
The longest delay was for the planes already assembled because there was limited space to work. At least three of those have completed (N787EX, N787BA and N7874) and I expect the rest are well underway by now.
Dan23 From Australia, joined Jun 2005, 90 posts, RR: 0 Reply 3, posted (3 years 2 months 1 week 6 days 6 hours ago) and read 10348 times:
N787FT and N787ZA are also complete. 787's from LN16 onwards will be complete with modified SOB when they roll out of the factory.
So only Line Numbers 7, 8, 10-15 are left to be modified. I believe LN7 and LN8 are being worked on now and LN10 will move into the tent once LN9 is removed. The usual suspects on the scene may be able to confirm this.
With 3 frames being modified concurrently it would appear there is 5-6 months work left to complete them all.
petera380 From United States of America, joined Feb 2005, 323 posts, RR: 0 Reply 4, posted (3 years 2 months 1 week 5 days 22 hours ago) and read 9865 times:
LN9 is also complete, waiting to be moved out of the tent.
kanban From United States of America, joined Jan 2008, 2466 posts, RR: 21 Reply 5, posted (3 years 2 months 1 week 5 days 17 hours ago) and read 7027 times:
consider that with the flight test a/p's done, there really is no rush to do the others on a 3 shift basis... other than the rental cost on the tent.
WarpSpeed From United States of America, joined Feb 2010, 516 posts, RR: 3 Reply 6, posted (3 years 2 months 1 week 5 days 15 hours ago) and read 5190 times:
Quoting tdscanuck (Reply 2): Quoting UAL747-600 (Thread starter):
It appears that the most recent one N6066Z took almost 2 months (Jan. 12 - Mar. 9) to complete.
That's about right.
Does this time frame take into account the restoration of access doors, systems, seals and fasteners that are removed for SOB Mod? From what I gather, this is no simple task as when Boeing announces completion of an SOB Mod, the subject plane is diverted for a while to another area to be properly buttoned-up.
Quoting Dan23 (Reply 3): 787's from LN16 onwards will be complete with modified SOB when they roll out of the factory.
but only through aircraft 49. Beginning with aircraft 50, all 787's will incorporate a redesign of the area that lacked structural strength and, thus, eliminate the need for SOB Mods of any kind.
killtherabbit From United States of America, joined Dec 2006, 2 posts, RR: 0 Reply 7, posted (3 years 2 months 1 week 5 days 14 hours ago) and read 4974 times:
In response to WarpSpeed:
After Boeing makes a change to the wing box area like they are doing from frame 50 on, do they have to test that change on the test jig and pull the wing to 150%, or is finite analysis good enough?
To me this seems like a major change, and the FAA would want them to test it.
7673mech From United States of America, joined Mar 2004, 632 posts, RR: 0 Reply 8, posted (3 years 2 months 1 week 5 days 14 hours ago) and read 4440 times:
Quoting kanban (Reply 5): consider that with the flight test a/p's done, there really is no rush to do the others on a 3 shift basis... other than the rental cost on the tent.
And the rental cost of two Hangar bays at the ATS facility.
This is costing A LOT.
WarpSpeed From United States of America, joined Feb 2010, 516 posts, RR: 3 Reply 9, posted (3 years 2 months 1 week 5 days 13 hours ago) and read 3788 times:
Quoting killtherabbit (Reply 7): After Boeing makes a change to the wing box area like they are doing from frame 50 on, do they have to test that change on the test jig and pull the wing to 150%, or is finite analysis good enough?
To me this seems like a major change, and the FAA would want them to test it.
Good question and I had wondered the same...however, while I do not know the answer, I would not be surprised if someone else chimes in. IIRC, Airbus had some structural issues with the wing of its A380; the fix to which was "paper certified" rather than having verification via full scale testing. While not the same situation here, it could be that Boeing could do small scale testing and/or computer modeling to prove that the update is A-OK. Once again, I defer to those more knowledgeable.
dynamicsguy From Australia, joined Jul 2008, 765 posts, RR: 8 Reply 10, posted (3 years 2 months 1 week 5 days 7 hours ago) and read 3129 times:
Quoting WarpSpeed (Reply 6): Beginning with aircraft 50, all 787's will incorporate a redesign of the area that lacked structural strength and, thus, eliminate the need for SOB Mods of any kind
You sure about that line number? It doesn't make sense to incorporate a change like that at a line number other than one of the blockpoints.
Quoting killtherabbit (Reply 7): To me this seems like a major change, and the FAA would want them to test it.
The likelihood of Boeing building another static test airframe just to test this is vanishingly small. Like any other structural change it will certainly be certified by analysis, with the possibility of some small-scale testing.
WarpSpeed From United States of America, joined Feb 2010, 516 posts, RR: 3 Reply 11, posted (3 years 2 months 1 week 5 days 7 hours ago) and read 3051 times:
Quoting dynamicsguy (Reply 10): You sure about that line number? It doesn't make sense to incorporate a change like that at a line number other than one of the blockpoints.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 81 Reply 12, posted (3 years 2 months 1 week 5 days 5 hours ago) and read 2948 times:
Quoting WarpSpeed (Reply 6): Does this time frame take into account the restoration of access doors, systems, seals and fasteners that are removed for SOB Mod?
Yep.
Quoting WarpSpeed (Reply 6): From what I gather, this is no simple task as when Boeing announces completion of an SOB Mod, the subject plane is diverted for a while to another area to be properly buttoned-up.
Most of the mods have been restored in place.
Quoting killtherabbit (Reply 7): After Boeing makes a change to the wing box area like they are doing from frame 50 on, do they have to test that change on the test jig and pull the wing to 150%, or is finite analysis good enough?
Although the FAA could always insist, it's very unlikely they'd require a full scale test for something like that.
Quoting killtherabbit (Reply 7): To me this seems like a major change, and the FAA would want them to test it.
They would...but "test it" and "do a full scale ultimate strength test" are very different things. By the time line 50 rolls around, they'll have oodles of test data from the existing static airframe, probably some loads and structural data from the flying frames, and all the work they did on design/test/analysis during the side-of-body mod. I'd be very very surprised if they don't have enough fidelity in the loads and models to certify the change without another full ultimate load strength test.
Keep in mind that they don't even redo the ultimate strength test for major derivatives, and the change between, say, a 777-200 original and a 777-300ER is a whole lot larger than between the different side-of-body blockpoints of the 787-8.
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