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DLHAM
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Few questions about the A310 (and A300)

Thu Oct 08, 2020 8:41 pm

1) First a simple one: what are these two rather big "intakes" for at the bottom of the fuselage?

Image

2) Why do the A300 and A310 seem to have no wingbox? Or to be more precise: a very small wingbox behind the wing, if it is a wingbox at all. All other aircraft I can imagine have a wingbox/a significantly larger wingbox.

Image

3) What are the exact differences between the A310-221 and A310-222? I googled it, some sources say they share the same engine, some sources say they share the same engine but the -222 has a different engine version. What I couldnt find is if the -222 has a higher MTOW and higher fuel capacity? I know that Pan Am's N801-804PA were only used for IGS and Europe in the first years, they were A310-221s and did not have the range for the atlantic. From 1986 three A310-222s arrived that had transatlantic range for shorter TATL flights. These four -221s were later reconfigured and "upgraded" to -222s. So the -222 seems to have more range. I would love to know how that upgrade looked like. I dont think that the differences are too big, could even imagine that this mainly was a paperwork upgrade.
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Starlionblue
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 12:52 am

1) The big intakes are ram air intakes for pack cooling. You'll find these on pretty much every airliner, typically under centre fuselage, though the MD-80 has an intake at the base of the fin.

This diagram shows the ram air duct in blue.
Image

2) I think you mean the wing/fuselage fairing. The wingbox is a structural element and it is inside the fuselage. The fairing is an aerodynamic shell and has no structural function. The larger fairings seen in more modern aircraft are a result of improvements in aerodynamic design, largely driven by massively increased computational capacity. The wing/fuselage area has complex aerodynamics, which are complex to model. For area ruling back in the day, it was less complex to use larger flap track fairings.

If you look at aircraft more or less contemporary to the A330, like the Tristar and the DC-10, they don't have large fairings either.

3) AFAIK the -221 has the JT9D-7R4D1 and the -222 has the JT9D-7R4E1. I don't know what the difference is but I get the impression this might be the same engine with different ratings. If that is correct, being able to "upgrade" to the -222 standard would make sense.
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ELBOB
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 6:11 am

DLHAM wrote:
1) First a simple one: what are these two rather big "intakes" for at the bottom of the fuselage?


They are indeed ram intakes but well out of scale on that model. They don't look like torpedo tubes on the real aircraft...

Starlionblue wrote:
The wing/fuselage area has complex aerodynamics, which are complex to model. For area ruling back in the day, it was less complex to use larger flap track fairings.

If you look at aircraft more or less contemporary to the A330, like the Tristar and the DC-10, they don't have large fairings either.


It's not area ruling; that would require pinching the fuselage at the wing root, not bulking it out with fairings.

The A300 wing is mid-mounted and simply didn't require a fairing:

Image
 
Lukas757
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 6:29 am

Starlionblue wrote:
If you look at aircraft more or less contemporary to the A330, like the Tristar and the DC-10, they don't have large fairings either.


Actually, the DC-10 does have a quite large fairing underneath and behind the wing, which even got extended as far as half way on top of the cargo door. But yes, the leading edge area looks similar to the A300.
 
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Starlionblue
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 8:11 am

ELBOB wrote:
DLHAM wrote:
1) First a simple one: what are these two rather big "intakes" for at the bottom of the fuselage?


They are indeed ram intakes but well out of scale on that model. They don't look like torpedo tubes on the real aircraft...

Starlionblue wrote:
The wing/fuselage area has complex aerodynamics, which are complex to model. For area ruling back in the day, it was less complex to use larger flap track fairings.

If you look at aircraft more or less contemporary to the A330, like the Tristar and the DC-10, they don't have large fairings either.


It's not area ruling; that would require pinching the fuselage at the wing root, not bulking it out with fairings.

The A300 wing is mid-mounted and simply didn't require a fairing:

Image


It is area ruling. The wing is mid-mounted but it is also swept and tapered, so the total cross-section decreases aftward. The flap tracks and/or wing/body fairing are used to taper the cross-section after the wing midline for area ruling purposes.

The Convair 990 had large "shock bodies" on the trailing edge for the purpose. This type of design was later integrated in the flap track fairings.

Image

The A380 is a prime example of using the wing/fuselage fairing for area ruling.

Image

Lukas757 wrote:
Starlionblue wrote:
If you look at aircraft more or less contemporary to the A330, like the Tristar and the DC-10, they don't have large fairings either.


Actually, the DC-10 does have a quite large fairing underneath and behind the wing, which even got extended as far as half way on top of the cargo door. But yes, the leading edge area looks similar to the A300.


Fair. But not nearly as massive as on the A380, for example.
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hitower3
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 11:11 am

Dear all,
Please let me apologize for the digression, but I have got a question regarding the area rule / flap track fairing on the 747SP: unlike any other 747, the SP seems not to have these devices.
Why not?

Hendric
 
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Starlionblue
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 11:32 am

hitower3 wrote:
Dear all,
Please let me apologize for the digression, but I have got a question regarding the area rule / flap track fairing on the 747SP: unlike any other 747, the SP seems not to have these devices.
Why not?

Hendric


The 747SP had single slot flaps as opposed to the triple slot flaps on the 747-100/200. This made sense given the lower weight. I do get the impression, however, that the wing body fairing aft of the wing was larger, which would make sense due to area ruling.

Happy to be proven wrong by the 747 experts on the board.

Image
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extender
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 11:33 am

hitower3 wrote:
Dear all,
Please let me apologize for the digression, but I have got a question regarding the area rule / flap track fairing on the 747SP: unlike any other 747, the SP seems not to have these devices.
Why not?

Hendric


The SP used a more simple design. It did not use the triple slot like on the -100/-200.
 
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DLHAM
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 6:44 pm

Thank you very much for your answers! Additional to the answers I learned something I never heard of, after being an Avgeek for at least 25 years: area ruling.
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Starlionblue
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Re: Few questions about the A310 (and A300)

Fri Oct 09, 2020 11:33 pm

I'll add that the wing/fuselage fairing is by no means only there for area ruling. Its other major function is smoothing out airflow and the wing/fuselage interface. Due to the two different shapes meeting, there are complex and frequently turbulent interactions in this area.

DLHAM wrote:
Thank you very much for your answers! Additional to the answers I learned something I never heard of, after being an Avgeek for at least 25 years: area ruling.


Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.
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Faro
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Re: Few questions about the A310 (and A300)

Sat Oct 10, 2020 10:41 am

Starlionblue wrote:
Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.



Then you may have noticed that the 777X now has 5 flap track fairings per wing versus 3 on the earlier 777 designs. I presume it's principally for area ruling, although it does impose a not-insignificant drag penalty at lower, non-transonic speeds.


Faro
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Starlionblue
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Re: Few questions about the A310 (and A300)

Sat Oct 10, 2020 11:28 am

Faro wrote:
Starlionblue wrote:
Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.



Then you may have noticed that the 777X now has 5 flap track fairings per wing versus 3 on the earlier 777 designs. I presume it's principally for area ruling, although it does impose a not-insignificant drag penalty at lower, non-transonic speeds.


Faro


Area ruling probably plays a part, but I think the main reason is that the outboard flap has gone from a single piece on the 777 Classic to two sections on the 777X. The two outboard flap sections each have two flap tracks, and consequently flap track fairings.

Image
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LH707330
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Re: Few questions about the A310 (and A300)

Sat Oct 10, 2020 9:17 pm

Starlionblue wrote:
Faro wrote:
Starlionblue wrote:
Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.



Then you may have noticed that the 777X now has 5 flap track fairings per wing versus 3 on the earlier 777 designs. I presume it's principally for area ruling, although it does impose a not-insignificant drag penalty at lower, non-transonic speeds.


Faro


Area ruling probably plays a part, but I think the main reason is that the outboard flap has gone from a single piece on the 777 Classic to two sections on the 777X. The two outboard flap sections each have two flap tracks, and consequently flap track fairings.

Image

That helps clear that up, thanks. Maybe they just copied the A300's design :D

What I'm curious about is why Airbus did the mid-wing mount on the 300/310 in the first place, what was the point of that? Most of the other designs of that day had a pretty low wing mount.
 
e38
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Re: Few questions about the A310 (and A300)

Mon Oct 12, 2020 12:43 am

LH707330, reference your question above, "why Airbus did the mid-wing mount on the 300/310 in the first place . . .'

I do not have specific numbers to substantiate this, but my understanding is that the mid-wing mount allowed for greater underfloor cargo capability.

e38
 
LH707330
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Re: Few questions about the A310 (and A300)

Mon Oct 12, 2020 10:24 pm

Cool, thanks for the info!
 
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Re: Few questions about the A310 (and A300)

Tue Oct 13, 2020 1:36 pm

e38 wrote:
LH707330, reference your question above, "why Airbus did the mid-wing mount on the 300/310 in the first place . . .'

I do not have specific numbers to substantiate this, but my understanding is that the mid-wing mount allowed for greater underfloor cargo capability.

e38

All these types seem to have a wingbox that is just under the pax floor.
What is different (vs. the establlished widebodies of the time ) on the Airbus A300
and forward is that the pax floor sits rather high in the fuselage.
This allowed a smaller diameter fuselage that still was able to take established ULDs in the belly.
( compare cross sections : 747, A300 DC10, TriStart.)
767 (smaller dia. ) has its own shrink ULD.

With the A340/A330 the wing got quite a bit larger and _much thicker_.
Another design metric ( beyond aero considerations ) that forced belly fairings.
( and today belly fairings seem to be home to a plethora of gimmicks.)
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trent768
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 8:47 am

ELBOB wrote:
The A300 wing is mid-mounted and simply didn't require a fairing:

Image

Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.
 
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 10:11 am

trent768 wrote:
ELBOB wrote:
The A300 wing is mid-mounted and simply didn't require a fairing:

Image

Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.


A low mounted wing needs more dihedral than a mid mounted one to achieve equivalent stability.

However, I'm not really certain the A330 wing is mounted lower. This may be an impression given by the much thicker wing root.
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DLHAM
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 4:32 pm

Starlionblue wrote:
trent768 wrote:
ELBOB wrote:
The A300 wing is mid-mounted and simply didn't require a fairing:

Image

Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.


A low mounted wing needs more dihedral than a mid mounted one to achieve equivalent stability.

However, I'm not really certain the A330 wing is mounted lower. This may be an impression given by the much thicker wing root.


If you ask me the A330(/340) wing is not mounted any lower. But AFAIK its quite a bit thicker so it does not look like its mounted so high.
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426Shadow
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 6:11 pm

Starlionblue wrote:
I'll add that the wing/fuselage fairing is by no means only there for area ruling. Its other major function is smoothing out airflow and the wing/fuselage interface. Due to the two different shapes meeting, there are complex and frequently turbulent interactions in this area.

DLHAM wrote:
Thank you very much for your answers! Additional to the answers I learned something I never heard of, after being an Avgeek for at least 25 years: area ruling.


Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.


Interestingly the X-35 had a rather obvious area ruled fuselage compared to the production one which is pretty much non-existent. Almost like the original F-102 being the successor to the F-106 instead of the way it actually went down.

Image

Image
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Okcflyer
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 7:03 pm

trent768 wrote:
ELBOB wrote:
The A300 wing is mid-mounted and simply didn't require a fairing:

Image

Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.


Large downside ... longer than necessary landing gear. This requires additional strengthening in the gear to handle the longer moment arms, but also raw weight of extra length.

Whether that weight gain gets offset somewhere, I’m not sure. I don’t think it’s accidental the aircraft since have wing bottom in line with fuse botttom, or even below in some cases.
 
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Starlionblue
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Re: Few questions about the A310 (and A300)

Wed Oct 14, 2020 11:43 pm

Okcflyer wrote:
trent768 wrote:
ELBOB wrote:
The A300 wing is mid-mounted and simply didn't require a fairing:

Image

Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.


Large downside ... longer than necessary landing gear. This requires additional strengthening in the gear to handle the longer moment arms, but also raw weight of extra length.

Whether that weight gain gets offset somewhere, I’m not sure. I don’t think it’s accidental the aircraft since have wing bottom in line with fuse botttom, or even below in some cases.


The parts of the wing sitting that low are aerodynamic, not structural. The landing gear is attached to a wing spar, which won't be that low. So making a "deeper" wing doesn't change the landing gear structure much.
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Okcflyer
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Re: Few questions about the A310 (and A300)

Thu Oct 15, 2020 12:45 am

Starlionblue wrote:
Okcflyer wrote:
trent768 wrote:
Omg, I never realised how high and thin the wing on the A300/310 is! Whenever I looked at the 300/310 and the 330/340 exterior, I have the impression that the later are just a more updated stretch of the former with a new set of wings, stabiliser, engines, etc. I always knew that there are something that completely different but couldn't point it out. Now I just realised that the difference is the wing mounting position.

Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.


Large downside ... longer than necessary landing gear. This requires additional strengthening in the gear to handle the longer moment arms, but also raw weight of extra length.

Whether that weight gain gets offset somewhere, I’m not sure. I don’t think it’s accidental the aircraft since have wing bottom in line with fuse botttom, or even below in some cases.


The parts of the wing sitting that low are aerodynamic, not structural. The landing gear is attached to a wing spar, which won't be that low. So making a "deeper" wing doesn't change the landing gear structure much.


Note how much shorter the A330 gear is.

Image

Other factor is the gear placement retracted. The wing body flaring covers gear wheels in the A330 (and most other air craft). Otherwise the gear has to the longer or mounting points closer to centerline to get a long enough swing. Wing root thickness and fuse height and relative wing placement go into this as well.

Anyway, back on track
 
trent768
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Re: Few questions about the A310 (and A300)

Thu Oct 15, 2020 4:05 am

Okcflyer wrote:
Starlionblue wrote:
Okcflyer wrote:

Large downside ... longer than necessary landing gear. This requires additional strengthening in the gear to handle the longer moment arms, but also raw weight of extra length.

Whether that weight gain gets offset somewhere, I’m not sure. I don’t think it’s accidental the aircraft since have wing bottom in line with fuse botttom, or even below in some cases.


The parts of the wing sitting that low are aerodynamic, not structural. The landing gear is attached to a wing spar, which won't be that low. So making a "deeper" wing doesn't change the landing gear structure much.


Note how much shorter the A330 gear is.

Image

Other factor is the gear placement retracted. The wing body flaring covers gear wheels in the A330 (and most other air craft). Otherwise the gear has to the longer or mounting points closer to centerline to get a long enough swing. Wing root thickness and fuse height and relative wing placement go into this as well.

Anyway, back on track

Ah okay, I can totally see it now; it's the thicc wing root and the presence of wing fairing that gave me the 330's bottom mounted wing. By looking at the bottom part of L1/R1 exit, it's visible how the top part of the wing root are at about the same level.

Thanks a lot people! It's still amazed me how a conversation about wing thickness of an almost extinct species of floating metal tube is considered so normal here. When people around me thought that my "ability to recognise which manufacturers made the aircrafts flying above us" just by its strobe light is super weird hahaha!
 
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Re: Few questions about the A310 (and A300)

Thu Oct 15, 2020 5:31 am

Okcflyer wrote:
Starlionblue wrote:
Okcflyer wrote:

Large downside ... longer than necessary landing gear. This requires additional strengthening in the gear to handle the longer moment arms, but also raw weight of extra length.

Whether that weight gain gets offset somewhere, I’m not sure. I don’t think it’s accidental the aircraft since have wing bottom in line with fuse botttom, or even below in some cases.


The parts of the wing sitting that low are aerodynamic, not structural. The landing gear is attached to a wing spar, which won't be that low. So making a "deeper" wing doesn't change the landing gear structure much.


Note how much shorter the A330 gear is.



I still don't think it is shorter. You just can't see as much of it. The A330 wing is thicker, the engines are much larger and so is the wing/body fairing. This all gives the impression that the A330 gear is shorter in comparison.

I've looked up into A330 gear wells hundreds of times. The legs go up quite a ways into the wing. Look at how much human fits inside. ;) Granted, I've never done a walkaround on an A300.

Image

If you look in the airport planning documents for the aircraft and compare the measurements, the fuselage and wing ground clearances are within centimetres of each other. However, the A330 engines have about half a meter less ground clearance because they are so much larger.

https://www.airbus.com/aircraft/support ... stics.html
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Max Q
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Re: Few questions about the A310 (and A300)

Thu Oct 15, 2020 9:44 am

426Shadow wrote:
Starlionblue wrote:
I'll add that the wing/fuselage fairing is by no means only there for area ruling. Its other major function is smoothing out airflow and the wing/fuselage interface. Due to the two different shapes meeting, there are complex and frequently turbulent interactions in this area.

DLHAM wrote:
Thank you very much for your answers! Additional to the answers I learned something I never heard of, after being an Avgeek for at least 25 years: area ruling.


Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.


Interestingly the X-35 had a rather obvious area ruled fuselage compared to the production one which is pretty much non-existent. Almost like the original F-102 being the successor to the F-106 instead of the way it actually went down.

Image

Image



Interesting how much ‘draggier’ that F35 looks in comparison to the prototype

I wonder if the X35 had an internal weapons bay
The best contribution to safety is a competent Pilot.


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Starlionblue
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Re: Few questions about the A310 (and A300)

Thu Oct 15, 2020 10:12 am

Max Q wrote:
426Shadow wrote:
Starlionblue wrote:
I'll add that the wing/fuselage fairing is by no means only there for area ruling. Its other major function is smoothing out airflow and the wing/fuselage interface. Due to the two different shapes meeting, there are complex and frequently turbulent interactions in this area.



Area ruling fascinates me.

There's an interesting story in the evolution from the Delta Dagger into the Delta Dart. By "coke bottling" the fuselage, performance was massively increased due to a decrease in transonic drag.

Area ruling can also be seen in canopy shapes, for example on the F-22.


Interestingly the X-35 had a rather obvious area ruled fuselage compared to the production one which is pretty much non-existent. Almost like the original F-102 being the successor to the F-106 instead of the way it actually went down.

Image

Image



Interesting how much ‘draggier’ that F35 looks in comparison to the prototype

I wonder if the X35 had an internal weapons bay


It did not. Neither did it have "mission avionics". Which is why the F-35 is fatter. No radar either. The X-35 was really a demonstrator, not a prototype, so there was quite some evolution going to the F-35.

https://www.codeonemagazine.com/article.html?item_id=28
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DLHAM
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Re: Few questions about the A310 (and A300)

Fri Oct 16, 2020 11:31 am

Starlionblue wrote:
Okcflyer wrote:
Starlionblue wrote:

The parts of the wing sitting that low are aerodynamic, not structural. The landing gear is attached to a wing spar, which won't be that low. So making a "deeper" wing doesn't change the landing gear structure much.


Note how much shorter the A330 gear is.



I still don't think it is shorter. You just can't see as much of it. The A330 wing is thicker, the engines are much larger and so is the wing/body fairing. This all gives the impression that the A330 gear is shorter in comparison.

I've looked up into A330 gear wells hundreds of times. The legs go up quite a ways into the wing. Look at how much human fits inside. ;) Granted, I've never done a walkaround on an A300.

Image

If you look in the airport planning documents for the aircraft and compare the measurements, the fuselage and wing ground clearances are within centimetres of each other. However, the A330 engines have about half a meter less ground clearance because they are so much larger.

https://www.airbus.com/aircraft/support ... stics.html


I worked as a ramp agent and handled both A300/310s and A330s. If you ask me the A330 gear is not shorter. It may look shorter because it sits a bit further away from the fuselage/further outside on the wing and the tires are larger and also positioned further apart, this makes it look shorter. Also the A330 seems to sit higher on the ground with its butt, so I dont think the gear is any shorter, but this could be due to the larger tires. If I remember correctly the A300/310 main gear does not "disappear" as much into the wing as the A330 gear.
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WIederling
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Re: Few questions about the A310 (and A300)

Fri Oct 16, 2020 12:21 pm

trent768 wrote:
Is there any benefits from having a mid-mounted wing instead of a bottom-mounted one? My instinct immediately said that it have something to do with stability, but I've been proven to be wrong in the past.



"mid versus low mounted"

That imho is a misconception.
All wingbox top sides sit just below the pax floor.
Height and length of the wingbox is what changes the appearance
of the A330 vs. the A300.

The 222" Airbus cross section has the pax floor higher in the fuselage than other WB designs.
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DLHAM
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Re: Few questions about the A310 (and A300)

Wed Oct 21, 2020 9:58 pm

Another question: the A300-600 got a lot if not almost all enhancements that the A310 got over the original A300B -- but not its wing. Does anyone know why? AFAIK the completely new designed wing of the A310 was absolutely state of the art and very advanced, why didnt they give the A310s wing to the A300-600? Two things I could think of:
- The A310 wing was more designed/optimized for longer routes while the average flight lenght of the A300 market is shorter?
- The A310 wing was designed to exactly fit the A310 size and weight and the A300 would have suffered from a performance hit with that wing?
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LH707330
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Re: Few questions about the A310 (and A300)

Wed Oct 21, 2020 11:31 pm

DLHAM wrote:
Another question: the A300-600 got a lot if not almost all enhancements that the A310 got over the original A300B -- but not its wing. Does anyone know why? AFAIK the completely new designed wing of the A310 was absolutely state of the art and very advanced, why didnt they give the A310s wing to the A300-600? Two things I could think of:
- The A310 wing was more designed/optimized for longer routes while the average flight lenght of the A300 market is shorter?
- The A310 wing was designed to exactly fit the A310 size and weight and the A300 would have suffered from a performance hit with that wing?

The second option. The wing was indeed great, but it was too small for the 300. Much of that R&D made its way into the 330/340 wing, with its deep root and high AR, making that pair into great performers.
 
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DL_Mech
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Re: Few questions about the A310 (and A300)

Thu Oct 22, 2020 1:21 am

DLHAM wrote:
why didnt they give the A310s wing to the A300-600?


Maybe the -600R needed the outboard ailerons that the A310 lacked?
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DLHAM
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Re: Few questions about the A310 (and A300)

Thu Oct 22, 2020 3:49 am

DL_Mech wrote:
DLHAM wrote:
why didnt they give the A310s wing to the A300-600?


Maybe the -600R needed the outboard ailerons that the A310 lacked?


AFAIK the -600R has no outboard ailerons as well.

Interesting as the A330/340 have no inboard ailerons -- the other way round.
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Starlionblue
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Re: Few questions about the A310 (and A300)

Thu Oct 22, 2020 7:32 am

DLHAM wrote:
DL_Mech wrote:
DLHAM wrote:
why didnt they give the A310s wing to the A300-600?


Maybe the -600R needed the outboard ailerons that the A310 lacked?


AFAIK the -600R has no outboard ailerons as well.

Interesting as the A330/340 have no inboard ailerons -- the other way round.


The A330/A340 does have inboard ailerons. They're right next to the outboard ones. :D

Airbus went with an unbroken flapline for better low-speed performance on the A330/A340 (and subsequently on the A380 and A350). The downside is the need for a stiffer (and thus heavier) wing to counteract aileron reversal.

FBW makes things easier since surface deflection can be finely tailored to speed and configuration. Thus no need for a "high-speed aileron". Even so, the outboard ailerons are locked out above 190 knots in clean configuration.
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