TheBigOne From United Kingdom, joined Sep 2004, 239 posts, RR: 0 Posted (7 years 4 months 2 weeks 5 days 14 hours ago) and read 2272 times:
Having seen a number of articles recently regarding the all composite structure of the B787, I started wondering what impact, if any, this would have on its second hand value in 20 years? Many modern airliners are converted into freighters with new cargo doors fitted to the fuselage. With the 787 being all composite, would this create problems? Can composite structures be altered with the same ease as current metal structures? Similarly with composite structures having different fatigue tendencies as compared to metal structures, could this be an advantage in the cargo market where normally passenger to freighter conversions need strengthening? I look forward to your replies, and any posts that attempt to turn this into a 787 v A350 post will be reported for deletion.
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Kaitak744 From United States of America, joined Jul 2005, 2208 posts, RR: 3 Reply 1, posted (7 years 4 months 2 weeks 5 days 13 hours ago) and read 2217 times:
Well, Boeing them selves did state that composite aircraft, unlike the aluminum/copper/ect. alloy aircraft, can be recycled. This means no 787s in the desert. If an operator wishes to convert to freighter, I am sure Boeing will find a way. .
TheBigOne From United Kingdom, joined Sep 2004, 239 posts, RR: 0 Reply 2, posted (7 years 4 months 2 weeks 5 days 13 hours ago) and read 2212 times:
Quoting Kaitak744 (Reply 1): Well, Boeing them selves did state that composite aircraft, unlike the aluminum/copper/ect. alloy aircraft, can be recycled.
Wow - That is interesting! So what kind of recycling are we talking about? I mean are sections of the aircraft going to be recycled as is, or are they going to end up as tupperware?
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Newark777 From United States of America, joined Dec 2004, 9348 posts, RR: 33 Reply 3, posted (7 years 4 months 2 weeks 5 days 12 hours ago) and read 2192 times:
Well, you can technically say airliners in use now are "recycled", since their scrap can be melted down and used again.
Areopagus From United States of America, joined Sep 2001, 1357 posts, RR: 1 Reply 4, posted (7 years 4 months 2 weeks 5 days 12 hours ago) and read 2185 times:
"Recycled", as in grinding it up and mixing with asphalt to build roads?
Ozair From Australia, joined Jan 2005, 663 posts, RR: 1 Reply 6, posted (7 years 4 months 2 weeks 5 days 12 hours ago) and read 2170 times:
Using a 787 even in 20 years to build a road seems like a waste of a good airplane. Surely we are talking about something a little more exotic than asphalt?
Atmx2000 From United States of America, joined Oct 2004, 4576 posts, RR: 39 Reply 7, posted (7 years 4 months 2 weeks 5 days 12 hours ago) and read 2151 times:
Quoting Ozair (Reply 6): Using a 787 even in 20 years to build a road seems like a waste of a good airplane. Surely we are talking about something a little more exotic than asphalt?
How about 30 years? That was what I thought the expected airframe lifetime was.
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TheBigOne From United Kingdom, joined Sep 2004, 239 posts, RR: 0 Reply 8, posted (7 years 4 months 2 weeks 5 days 9 hours ago) and read 2071 times:
So does that mean that potentially there could be B767F / B744F / A306F flying long after the first 787s are turned to tarmac? Sounds a little implausible to me!
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AeroWeanie From United States of America, joined Dec 2004, 1601 posts, RR: 52 Reply 9, posted (7 years 4 months 2 weeks 5 days 5 hours ago) and read 1962 times:
Quoting Kaitak744 (Reply 1): Well, Boeing them selves did state that composite aircraft, unlike the aluminum/copper/ect. alloy aircraft, can be recycled.
I think you have this backwards. Metal airplanes can be recycled - you simply melt down the metal and add it to the feedstream. Composites, especially carbon fiber, cannot be recycled. Witness what Raytheon is doing to all the Starships - incinerating them. Fiberglass cannot be recycled either. Every Corvette body will end up in a landfill or museum.
Trex8 From United States of America, joined Nov 2002, 3970 posts, RR: 14 Reply 10, posted (7 years 4 months 2 weeks 5 days 5 hours ago) and read 1959 times:
freighter conversions are unlikely, it will be very difficult to cut the fuselage
and expect the strength to be maintained , this is why B has said special military ops variants as has been seen with the 707 and less so the 767 will be very unlikely with the 787, unless they were built from scratch as such, which would only then be economical if there was a high enough production run. its probably not impossible but the technical problems are far greater than on a traditional metal fuselage where you can cut out sections and then strengthen areas
Beaucaire From Syria, joined Sep 2003, 5252 posts, RR: 26 Reply 11, posted (7 years 4 months 2 weeks 5 days 5 hours ago) and read 1943 times:
An aspect nobody ever mentioned in relation with all composite aircraft is the smell in such structures.
If you decend into the belly of an all composite boat it smells like hell- the odor -specifiaclly in warm weather or heat- is not amusing.I would not go as far as saying structures like the 787 are unsafe -but one will discover sooner or later aspects related to all-composite structures that are not being anticipated...
Recycling plastic -all composites is not as simple as melting down the fuselage -there is a complex mix of fibers,resin and other synthetic material that do not neccessarily allow an all combined melting-process.
Zvezda From Lithuania, joined Aug 2004, 10511 posts, RR: 65 Reply 12, posted (7 years 4 months 2 weeks 5 days 5 hours ago) and read 1910 times:
It would be possible to cut out a large cargo door. However, if this is not anticipated in the initial laying down of the carbon-fibre tape, then some reinforcement may need to be done around the new door openings. Not a big problem, but something to consider.
Most likely, completely new floor beams would be fitted.
NAV20 From Australia, joined Nov 2003, 9084 posts, RR: 37 Reply 13, posted (7 years 4 months 2 weeks 5 days 4 hours ago) and read 1864 times:
As far as I know the reason that jet airliners get re-cycled at all is that they are designed for a thirty-year life or so. The main limitation is the number of pressurisation/de-pressurisation cycles they undergo; after a certain number of flights the risk of failure due to metal fatigue (a' la Comet 1) is too great to allow them to continue flying.
Interestingly, someone mentioned on another thread that composites, unlike aluminium, reach a 'fatigue floor'; beyond a certain point, they do not weaken further in use.
I've said elsewhere that the 787 might become the next DC3 Dakota. Since they are not pressurised, and do not therefore suffer Comet-style fatigue - and also because they remain just about the most fuel-efficient piston-engined transport aeroplane ever built - there are still a number of Dakotas still in service. Perhaps the 787s will do the same - 'refuse' to wear out or become obsolete, and remain in service for the next 50 years or so!
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DAYflyer From United States of America, joined Sep 2004, 3807 posts, RR: 4 Reply 14, posted (7 years 4 months 2 weeks 5 days 4 hours ago) and read 1848 times:
So I gather cargo operators would then kinda need to order them new.
Phollingsworth From United Kingdom, joined Mar 2004, 825 posts, RR: 6 Reply 15, posted (7 years 4 months 2 weeks 5 days 4 hours ago) and read 1844 times:
Quoting AeroWeanie (Reply 9): Composites, especially carbon fiber, cannot be recycled. Witness what Raytheon is doing to all the Starships - incinerating them. Fiberglass cannot be recycled either. Every Corvette body will end up in a landfill or museum.
No entirely true, see the following
Quoting Beaucaire (Reply 11): Recycling plastic -all composites is not as simple as melting down the fuselage -there is a complex mix of fibers,resin and other synthetic material that do not neccessarily allow an all combined melting-process.
The problem is not with the reinforcement fibers but with the matrix. Carbon fiber, which is essentially graphite can easily be reused, in-fact there are quite a few exothermic reactions that can be created using graphite (initiation energy is high though). Glass fiber just that glass, it can also be recycled. Where the problem lies is in the thermoset plastic matrix. There is currently no economic way to separate the matrix from the fibers. Hence why Raytheon is incinerating the old Starships. However, this only prevents direct recycling. The material can always be recycled into other forms, such as Boeing's asphalt idea.
BHMBAGLOCK From United States of America, joined Jul 2005, 2698 posts, RR: 5 Reply 16, posted (7 years 4 months 2 weeks 5 days 4 hours ago) and read 1833 times:
Boeing has extensive experience with mechanically fastened composite assemblies in the V-22 and other programs that could be applied towards freighter modifications of the 787 in the future. Unfortunately, this is much more expensive than the initial production methods used on the 787 and I don't honsestly know if it would be cost effective.
Kaitak744 From United States of America, joined Jul 2005, 2208 posts, RR: 3 Reply 17, posted (7 years 4 months 2 weeks 5 days 2 hours ago) and read 1727 times:
Quoting Newark777 (Reply 3): Well, you can technically say airliners in use now are "recycled", since their scrap can be melted down and used again.
No, there was a post earlier on A.net, and I read in an article that aircraft metal (the aluminium/copper/whatever) alloy CAN NOT be melted. The metal is treated with a certain type of chemical to prevent corrosion and what not. This chemical is toxic if it ends up in say soda cans.
Quoting AeroWeanie (Reply 9): I think you have this backwards. Metal airplanes can be recycled - you simply melt down the metal and add it to the feedstream. Composites, especially carbon fiber, cannot be recycled. Witness what Raytheon is doing to all the Starships - incinerating them. Fiberglass cannot be recycled either. Every Corvette body will end up in a landfill or museum.
Same thing. Metal can be recycled. Aircraft metal can not. If I come across that article, I will be sure to post it.
Newark777 From United States of America, joined Dec 2004, 9348 posts, RR: 33 Reply 18, posted (7 years 4 months 2 weeks 5 days ago) and read 1608 times:
Quoting Kaitak744 (Reply 17):
No, there was a post earlier on A.net, and I read in an article that aircraft metal (the aluminium/copper/whatever) alloy CAN NOT be melted. The metal is treated with a certain type of chemical to prevent corrosion and what not. This chemical is toxic if it ends up in say soda cans.
Well, I guess I was wrong then.
What do they do with this metal then after the planes are scrapped out in the desert?
TheBigOne From United Kingdom, joined Sep 2004, 239 posts, RR: 0 Reply 19, posted (7 years 4 months 2 weeks 4 days 17 hours ago) and read 1483 times:
So how does this affect the economics of an all composite aircraft? I know in the short term it probably does not matter as these aircraft offer better fuel economy than traditional structures. As they become common however and more designs enter the market place, is there a risk that airlines will not be able to bank on the cargo market to realize any residual value from the airframe?
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