UAL747
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Why No A330 With A340 Range?

Sat Apr 08, 2000 4:24 am

It would make sense for airbus to develop an A330 with the range of the A340. In fact, why do they even need the A340 at all? If the right engines could be developed, it would seem that it would be more effecient and cheaper to fly and maintain. Why does airbus continue pushing the A340 when they could do the exact same with the A330? If they could extend the range of the A330, then it might be more of a contender against the 777.
"Bangkok Tower, United 890 Heavy. Bangkok Tower, United 890 Heavy.....Okay, fine, we'll just turn 190 and Visual Our Way
 
D L X
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RE: Why No A330 With A340 Range?

Sat Apr 08, 2000 5:42 am

There are a lot of technical reasons why the 330 can't just be extended for greater range, or more accurately why the 340 having the same wing gets better range than the 330. I actually don't fully understand the reasons, but I'll try.

The 330 has two giant engines that together are heavier than the 340's 4 smaller engines total. This is important because engine weight affects range. Also, having 4 engines spread out along the wings helps with the wing structure so less weight is used in support, and more space is available for fuel. That seems rather counter intuitive, but think about how much wings want to bend upward due to their lift, and supporting something heavy (the fuselage) in the middle of the span. Twins have to have their engines close to the fuselage for safety reasons so there is even more tendancy for the wings to bend. That has to be counteracted by adding extra structural support inside the wing to make it bend less. Having four engines relieves that requirement some because the engines themselves prevent the wing from bending as much. Thus less extra support, and that space can be used for more fuel, and hence longer range.

The only way that the 330 will see 777x range is if two things happen: the wing would have to be completely redesigned for the role (as in different from the 340 wing) and larger engines (and landing gear) would have to be added as well to push the extra fuel weight. That is quite a daunting task, but I do see Airbus doing it in the future, especially if the 3XX actually happens. (In that case, the 340 may die off.)
 
CPDC10-30
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Don't Forget Etops

Sat Apr 08, 2000 6:12 am

Don't forget that of course the A340 is exempt from ETOPS rules by having four engines. They can fly a shorter route - if one is feasible. I heard on this board earlier that Canada and Russia are investigating cooperating on upgrading air navigation services in the far north. That way, flights from North America to Asia would be able to fly over the north pole, which is a shorter route. The A330 and 777 have to stay within 180 minutes of an alternate, while the A340 (also MD-11 and 747-400) would not be limited by these rules.

Anyways..four engines has a "classic" look like a 707 or DC-8.
 
Guest

RE: Don't Forget Etops

Sat Apr 08, 2000 6:39 am

Another reason would be marketing---If the A330 had the range of the A340, then it would compete with the latter rather than complementing it. Also, Airbus' philosophy that four engines are better suited in the long range role (5,000nm+), mainly ETOPS.
 
pilot21
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RE: Why No A330 With A340 Range?

Sat Apr 08, 2000 9:06 pm

As most of the reasons have been mentioned, I'll keep this short, bascially it comes down to wing design. When airbus were investigating the A330/A340 design concept, the found that due to the structural bending of the wings with the different engines on them them, a four engined airliner was better suited to flights of over 5,000 miles, and thus a two engined was better suited to a flight of less then 5000 miles. Thus the main reason is aerodynamics.
Aircraft I've flown: A300/A310/A320/A321/A330/A340/B727/B732/B733/B734/B735/B738/B741/B742/B744/DC10/MD80/IL62/Bae146/AR
 
John
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RE: Why No A330 With A340 Range?

Sat Apr 08, 2000 9:32 pm

The A330's different engine types ARE NOT AS HUGE and powerful as the 777's powerplants. Now those engines are HUGE! They dwarf the 330's by comparison.
 
D L X
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RE: Why No A330 With A340 Range?

Sun Apr 09, 2000 1:03 am

I would also add that Airbus now admits that the 5000nm rule they devised when creating the 330 and 340 is obsolete in that twins are quie capable beyond 5000nm. But that's because there are larger engines that were not available when the 330 and 340 were designed.
 
VC-10
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RE: Why No A330 With A340 Range?

Sun Apr 09, 2000 1:20 am

D L X writes that the A330 has a heavier wing structure than the A340. This is not the case, the A330/340 airframe structure, less the engine pylon attachments is identical.
 
D L X
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VC-10

Sun Apr 09, 2000 1:48 am

I may be wrong, but would you care to explain why supposedly identical wings don't have the same fuel capacity?

Since you work on these things, you may be able to clarify. I was under the assumption that the 340/330 wing is incredibly similar but the 330 wing has a couple of structural units to help the wing bend found on all twins where the 340 has a larger fuel cell there.
 
John
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How About The 330-200?

Sun Apr 09, 2000 4:05 am

This shorter fuselage version does have significantly longer range. US Airways is considering it, and may switch some options to the -200 variant. The A340-500/600 is also being evaluated for future use, should US Airways decide to venture out over the vast Pacific, which, I believe, in the near future, is probably inevitable. There's money to be made and lot's of routes to fly that remain uncharted, for the time being, anyway.
 
timz
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RE: Why No A330 With A340 Range?

Sun Apr 09, 2000 8:38 am

So far the flying public has been willing to trust Boeing and the FAA; they are willing to board twin-engine aircraft to go pretty much anywhere. But a "drama" (Airbus's word) on live TV (Crippled Airliner Struggles Toward Land! Film at 11!) would obviously spike the A340's popularity; the only question is, for how long?
 
Guest

RE: Why No A330 With A340 Range?

Sun Apr 09, 2000 10:00 am

The A330 was originally designed to be a short/medium haul airliner, and Airbus put it's money on the A340 as their long-haul type. When the A330 started doing longer flights, Airbus realised that by shrinking it they would have an excellent 767 competitor for Trans Atlantic routes in the A330-200.

However, Airbus is still putting it's name on the A340 as it's true long-haul type. This, I think, is the main reason why the A330 has not been taken further in this direction - it would hurt the A340. I'm sure there are no real techincal reasons why the A330's range couldn't be extended further, but Airbus don't really want to do it.

I believe the A340s range comes from the fact the whole aircraft is managed for efficiency - the engines are from a narrowbody aircraft, they only "sip" the fuel - this is also the reason why the A340 is underpowered - it's very efficient. On the other hand the A330 is overpowered and a real performer - twins have to be over powered because they only have one engine left if one fails. However, being overpowered and having 2 engines is less efficient than having 4 small engines and being a bit underpowered!
 
VC-10
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RE: D L X

Mon Apr 10, 2000 12:27 am

I bet you think I ignored your question.

I cannot substantiate my claim fully as I have not had an A330 course. I am going on the information supplied by the AI instructors on my 340 course at Toulouse, particularly when we went on a field visit to the 330/340 production line.

Tomorrow I will ask the question of one of our structures engineers who came from Airbus and was involved with the design so........watch this space...........
 
VC-10
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D L X

Mon Apr 10, 2000 11:01 pm

I have now spoken to our ex-A.I. structures guy who says :.......

Originally the A330/340 wings were identical but as both a/c were developed the wing skins have got thicker on the 340. Visually there is no difference (apart from the pylon attachments) and additionally, there is no additional structure in the 330 wing to cater for a heavier engine.

The difference in fuel capacities is attributable a different centre tank arrangement on the 330.
 
D L X
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RE: D L X

Tue Apr 11, 2000 6:45 am

So, how is this center tank different from on the 330 and 340? (I assume the 340's is bigger; can they put the 340 center tank on the 330?) Does the range of the 340 beat the 330 simply because it is carrying less engine weight?
 
VC-10
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RE: D L X

Tue Apr 11, 2000 6:50 am

As I said previously, I haven't had an A330 course, so I don't know. My tame structures man is just that, stuctures, not a systems man
 
D L X
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RE: D L X

Tue Apr 11, 2000 6:54 am

Well, you've been informative nonetheless. Thanks.
 
VC-10
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RE: D L X

Tue Apr 11, 2000 6:56 am

It's been a pleasure, I would have loved to have been able to answer your last question
 
Guest

RE: Why No A330 With A340 Range? DLX

Tue Apr 11, 2000 7:08 am

The difference about center-fuel tank on 340 and 330 is caused by the fourth landing gear on 340´s.
 
D L X
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Center Fuel Tank

Tue Apr 11, 2000 9:58 am

So, that's interesting. I guess that would make the 340 center tank smaller? Please correct this since it doesn't make much sense.
 
Guest

RE: Why No A330 With A340 Range?

Tue Apr 11, 2000 8:10 pm

The A340 has less cargo-capacity than 330, due to the fourth-gear, that also gives room for extra-fuel.
 
Guest

RE: Why No A330 With A340 Range?

Tue Apr 11, 2000 9:15 pm

I believe to have read from a previous issue of ‘Airliners’ magazine, that originally Airbus wanted two different wing designs, one optimized for the A330, the other for the A340. This would have been too expensive at the time hence the development of one common wing being a compromise between the two. I believe that this ‘compromise’ is the main reason that Airbus has developed the 500-600 version of the A340, notice the change in the wing design enhancing long range ability.
 
Guest

RE: Why No A330 With A340 Range?

Tue Apr 11, 2000 9:24 pm

Continuing of my previous: Another motivation for the A340 500-600 series structural enhancement, is that as the B777’s wing was never a compromise, allowing for better overall long-range performance.
 
VC-10
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RE: Why No A330 With A340 Range?

Wed Apr 12, 2000 1:46 am

The Ctr Ldg Gr on the 340 does not effect fuel capacity or cargo capacity as it is located in the unpressurised Wing Gear wheel well. The Wing torque box which is also the ctr fuel tank is fwd of the well & the aft cargo compt is aft of the well behind the pressure bulkhead.
 
VC-10
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Attn: D L X

Sun Apr 16, 2000 7:31 am

I have just spoken to someone who has just completed an A330 course, he tells me the 330 has no Ctr fuel tank
 
D L X
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RE: Attn: D L X

Sun Apr 16, 2000 7:34 am

Ahhhh. Now it all clicks.  

Thanks again.
 
Hamlet69
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RE: Why No A330 With A340 Range?

Sun Apr 16, 2000 10:02 am

This has been a very informative discussion. A big thank you to all of you who have contributed, especially Ual747 for posting the topic to begin with.

VC-10 wrote:
>he tells me the A330 has no Ctr fuel tank

So the next question, what's the possibility/feasibility that Airbus will open up the wing box to fuel, thereby creating a two-engined replacement for the A342/3, leaving the A345/6 for ultra-long range flights? IMO, the A330 is the best plane Airbus produces, and an extended-range A330 would better compete against the 777 than the A343.

Thanks again for the informative postings  

Hamlet69
Honor the warriors, not the war.