Taliesin
Final Assembly Line stage 1
In Thrust we trust
Posts: 228
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Post by Taliesin on Jun 18, 2015 19:28:08 GMT 1
as the A350-1000 is coming first I don't think it can Be a shrink of the -1100, which they have not committed to yet ? Of course it can. You size everything for the weights, loads and operational specs of the -1100, then make the -1000 a simple shrink. It doesn't matter which comes first, it matters which was the one that drove the design. The -1100 would be heavier any way as it would be longer, but that also gives you extra space for another fuel tank to get the range you want ? You don't store fuel in the fuselage, you store it in the wing or the tail plane.
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Post by stealthmanbob on Jun 18, 2015 19:53:26 GMT 1
as the A350-1000 is coming first I don't think it can Be a shrink of the -1100, which they have not committed to yet ? Of course it can. You size everything for the weights, loads and operational specs of the -1100, then make the -1000 a simple shrink. It doesn't matter which comes first, it matters which was the one that drove the design. The -1100 would be heavier any way as it would be longer, but that also gives you extra space for another fuel tank to get the range you want ? You don't store fuel in the fuselage, you store it in the wing or the tail plane. no not in the fuselage with the passengers ! But in the hold space underneath, best place for it is I guess where ? Close to the centre, you stick an extra tank down below, just behind or just in front of the wings or both ? You don't stick it in tail ! That would be really odd with the A350 which needs the tail to be balanced ! Where even the amount of paint on each side needs balancing !
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Taliesin
Final Assembly Line stage 1
In Thrust we trust
Posts: 228
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Post by Taliesin on Jun 18, 2015 20:56:51 GMT 1
But in the hold space underneath, best place for it is I guess where ? Close to the centre, you stick an extra tank down below, just behind or just in front of the wings or both ? There is a center tank, yes. But you don't actually tank more fuel in a stretch, you tank less. That's because typically, a stretch is not fuel volume limited, it's MTOW limited. If your MTOW is the same or only a little higher, more of it is eaten up by your ZFW, so the difference between ZFW and MTOW gets smaller, not bigger and you can tank less fuel. An additional tank would just remain empty. You don't stick it in tail ! That would be really odd with the A350 which needs the tail to be balanced ! Where even the amount of paint on each side needs balancing ! Actually, the A350 has a trim tank in the tail plane: www.flightglobal.com/assets/getasset.aspx?itemid=11016
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Taliesin
Final Assembly Line stage 1
In Thrust we trust
Posts: 228
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Post by Taliesin on Jun 18, 2015 21:15:27 GMT 1
That would be really odd with the A350 which needs the tail to be balanced ! Where even the amount of paint on each side needs balancing ! Well, it seems the A350 is the first Airbus wide body to not have a trim tank.. I was not aware of that. Either way, your post made it sound as if it was impossible... it's certainly not impossible, in fact, it's routinely done on many planes.
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s543
in service - 2 years
Posts: 3,957
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Post by s543 on Jun 18, 2015 21:22:29 GMT 1
I believe that "if" the 1100 would come - I have written later than 2019 probably later than 2020 - and than there might be new technologies ready so it all might come. Bigger more mature engine might be ready with better efficiency i.e. the range might be achievable, so it will not be a simple stretch but "1/2 of a neo". But again all this is just a speculation....... for us having fun
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Post by stealthmanbob on Jun 18, 2015 21:28:55 GMT 1
That would be really odd with the A350 which needs the tail to be balanced ! Where even the amount of paint on each side needs balancing ! Well, it seems the A350 is the first Airbus wide body to not have a trim tank.. I was not aware of that. Either way, your post made it sound as if it was impossible... it's certainly not impossible, in fact, it's routinely done on many planes. I was only talking about the A350 as that was the subject we were talking about ! About -900 -1000 and -1100
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Post by stealthmanbob on Jun 18, 2015 23:31:51 GMT 1
But in the hold space underneath, best place for it is I guess where ? Close to the centre, you stick an extra tank down below, just behind or just in front of the wings or both ? There is a center tank, yes. But you don't actually tank more fuel in a stretch, you tank less. That's because typically, a stretch is not fuel volume limited, it's MTOW limited. If your MTOW is the same or only a little higher, more of it is eaten up by your ZFW, so the difference between ZFW and MTOW gets smaller, not bigger and you can tank less fuel. An additional tank would just remain empty. You don't stick it in tail ! That would be really odd with the A350 which needs the tail to be balanced ! Where even the amount of paint on each side needs balancing ! Actually, the A350 has a trim tank in the tail plane: www.flightglobal.com/assets/getasset.aspx?itemid=11016You seem to contradict your self, one post you don't put fuel in the fuselage ! Then next you say there is a centre tank ?? It's obvious you stick the greatest amount of weight as central as you can ! In the middle, between the wings and above the undercarriage. PS when you stretch a plane you often put more powerful engines on it to lift the extra weight and extra fuel ! Say A350-900 compared to A350-1000 Different engine, same if you look back at the B777-200 compared to the stretched B777-300 ! The -300 has a higher MTOW yes, but more powerful engines to deal with it ! And guess what it has more range because it can carry more fuel, simples
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mjoelnir
in service - 2 years
Posts: 4,089
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Post by mjoelnir on Jun 18, 2015 23:59:26 GMT 1
There is a center tank, yes. But you don't actually tank more fuel in a stretch, you tank less. That's because typically, a stretch is not fuel volume limited, it's MTOW limited. If your MTOW is the same or only a little higher, more of it is eaten up by your ZFW, so the difference between ZFW and MTOW gets smaller, not bigger and you can tank less fuel. An additional tank would just remain empty. Actually, the A350 has a trim tank in the tail plane: www.flightglobal.com/assets/getasset.aspx?itemid=11016You seem to contradict your self, one post you don't put fuel in the fuselage ! Then next you say there is a centre tank ?? It's obvious you stick the greatest amount of weight as central as you can ! In the middle, between the wings and above the undercarriage. PS when you stretch a plane you often put more powerful engines on it to lift the extra weight and extra fuel ! Say A350-900 compared to A350-1000 Different engine, same if you look back at the B777-200 compared to the stretched B777-300 ! The -300 has a higher MTOW yes, but more powerful engines to deal with it ! And guess what it has more range because it can carry more fuel, simples You actually prefer to carry fuel in the wing and not in the center tank, or fuselage tank. More weight in the wing less in the fuselage allows a higher carried payload. Distributing load in or along the wing reduces stress with the same load. The A330-300 had the center tank in the wingbox disabled until now in the 242 t version for example.
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Taliesin
Final Assembly Line stage 1
In Thrust we trust
Posts: 228
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Post by Taliesin on Jun 19, 2015 0:22:48 GMT 1
Structurally, the center tank is part of the wing, not the fuselage. It counts as wing area.
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Jun 19, 2015 1:33:11 GMT 1
I am not sure that the 400-seat market is so large that it warrants a major effort from Airbus. While no airliner of that size has ever been built, let alone operated, airlines nowadays have a wide array of aircraft types to chose from. The market size is therefore an unknown.
Moreover, the main customers have already committed to the 777X. Airbus should focus on promoting the A35K.
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