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Is the A320 wing becoming too small

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Is the A320 wing becoming too small

Old 19th Nov 2019, 18:35
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Is the A320 wing becoming too small

This statement was written in to a magazine that I read recently. The A321 wing does seem to have some issues in terms of speedbrake operation as well. Is it time for a new wing design?

"The A320 wing was designed 35 years ago for a 70T platform and has remained the same on all versions, from the A318 through to the A321.While unchanged, the wing has seen a steady loading increase: to 83T on the first A321, then 89 and 93.5T, and is finally expected to go up to 101T on the A321XLR.This increased wing loading has meant higher takeoff speeds, reaching close to the maximum tyre speed limits. And a lower safety margin at altitude – in other words, a tighter “coffin corner”, and lower stability protection.Where and when would the civil aviation authorities stop manufacturers from creeping ever so closer to the performance limits of a product?"
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Old 19th Nov 2019, 18:44
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The A321 and A321LR have at least different high lift systems haven‘t they? I agree that more weight on the wing would make some entirely new wing useful. Especially with even more heavy stretched versions likely coming up.
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Old 19th Nov 2019, 20:57
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I believe the flaps on the NEO are double slotted. Not sure how much difference that makes.
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Old 19th Nov 2019, 21:15
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Flaps on all 321s (CEO and NEO) are double slotted. Partly as a result of the "packaging" challenge of that mechanism and the desire to add a bit more area the trailing edge of the flap extends a few centimetres further back giving another 4 square meters of wing, 128 instead of 124.
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Old 20th Nov 2019, 09:34
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Flight control software incorporates a load alleviation function on newer aircraft. Sharklet equipped models have noticeably better performance than non sharklet ones, even with the same engines.

However I agree regarding the wing, the B737 MAX is a perfect example of a manufacturer pushing a design too far. Any further increase in size or weight and Airbus needs to look at the wings. This would be worthwhile as improvements in technology over the last 30 years would likely deliver considerable gains and be worthwhile incorporating.
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Old 20th Nov 2019, 11:38
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While true that the wings on the A320 are already very dated, unlike actually the 737 which got completely new ones with the NG, there is of course the issue that it is pretty much impossible to increase the wingspan except if going for a folding wing design as Boeing does now on the 777X. Which of course would increase weight, complexity and maintenance requirements quite a bit, especially on an airplane that can and does something like 10 to 12 sectors a day. They went right up to the 36m maximum for a code C aircraft with the increase in wingspan that the sharklets provide (from 34,1 to 35,8m). They could increase the wing surface of course, but that has its downsides as well.

Will they do it? Well, they do think about a new narrow body aircraft anyway, but of course a different wing (and pleeeaaasee: an updated flight deck) could ensure continued production well into the next 10 to 20 years.
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Old 20th Nov 2019, 16:26
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Boeing stuck a new wing onto the B747-8, the older angular winglet designs on the B747-400 and A330 are starting to look very dated now when compared to the newer curved wings of the A350 and B787.
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Old 20th Nov 2019, 17:11
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The 321 wing has always been too small, indeed there are a couple of areas where I believe the regulators should have taken a firmer hand during certification. If a heavy 321 suffers a problem on departure and requires an immediate return then it is impossible to slow to below flap limiting speed without disconnecting the autothrottle.

Now I know the old folks on here will say 'so what'. Just bear in mind that many operators prohibit the diconnection of autothrust during normal flight as its considered too dangerous.

Had I been the certificating authority then I would have send Airbus away to put in a few more flap rivets and then return for another go.
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Old 20th Nov 2019, 17:56
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Doesn't a new wing = new type design and all the relevant delays with certification? In today's aviation I could see exactly why they would just keep old hardware and sell it on as 'new'.
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Old 20th Nov 2019, 18:02
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Originally Posted by flyingmed View Post
Doesn't a new wing = new type design and all the relevant delays with certification? In today's aviation I could see exactly why they would just keep old hardware and sell it on as 'new'.
737 has three different wings on the same type certificate. Although probably not the best example these days
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Old 20th Nov 2019, 18:52
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Originally Posted by ASRAAMTOO View Post
The 321 wing has always been too small, indeed there are a couple of areas where I believe the regulators should have taken a firmer hand during certification. If a heavy 321 suffers a problem on departure and requires an immediate return then it is impossible to slow to below flap limiting speed without disconnecting the autothrottle.

Now I know the old folks on here will say 'so what'. Just bear in mind that many operators prohibit the diconnection of autothrust during normal flight as its considered too dangerous.

Had I been the certificating authority then I would have send Airbus away to put in a few more flap rivets and then return for another go.
Er... . If a heavy 321 suffers a problem on departure and requires an immediate return then it is impossible to slow to below flap limiting speed without disconnecting the autothrottle.
Can you explain. I fly 321ceo (and 320neo) MLW departures out of LAS for example a couple of times a week.I could be missing something of course.....

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Old 20th Nov 2019, 19:10
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Originally Posted by neilki View Post
Er... . If a heavy 321 suffers a problem on departure and requires an immediate return then it is impossible to slow to below flap limiting speed without disconnecting the autothrottle.
Can you explain. I fly 321ceo (and 320neo) MLW departures out of LAS for example a couple of times a week.I could be missing something of course.....
Well our jets have a max tow of 84 tonnes, green dot at this weight is i think (without having all the docs to hand) 236 Kts. This would be the slowest speed the A/T will allow. Flap 1 limiting speed is (also without my notes) 230 Kts, so to get below flap limiting speed requires the disconnection of the A/T.

Perhaps other operators have bought more flap rivets!
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Old 20th Nov 2019, 20:58
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Originally Posted by ASRAAMTOO View Post
The 321 wing has always been too small, indeed there are a couple of areas where I believe the regulators should have taken a firmer hand during certification. If a heavy 321 suffers a problem on departure and requires an immediate return then it is impossible to slow to below flap limiting speed without disconnecting the autothrottle.
.
Interesting. Are you saying that Vls is faster than the flap limit speed at high weights?
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Old 20th Nov 2019, 21:00
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Originally Posted by ASRAAMTOO View Post
Well our jets have a max tow of 84 tonnes, green dot at this weight is i think (without having all the docs to hand) 236 Kts. This would be the slowest speed the A/T will allow. Flap 1 limiting speed is (also without my notes) 230 Kts, so to get below flap limiting speed requires the disconnection of the A/T.

Perhaps other operators have bought more flap rivets!
Oh I see. You don’t need to disconnect autothrust to deal with this, you just select a speed below green dot. The autothrust will happily work right down to Vls.
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Old 20th Nov 2019, 23:03
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Originally Posted by ASRAAMTOO View Post
Well our jets have a max tow of 84 tonnes, green dot at this weight is i think (without having all the docs to hand) 236 Kts. This would be the slowest speed the A/T will allow. Flap 1 limiting speed is (also without my notes) 230 Kts, so to get below flap limiting speed requires the disconnection of the A/T.

Perhaps other operators have bought more flap rivets!
We must have bought some heavy planes. I’ve seen 246/248kt a few times. Makes for a long climb to cruise.
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Old 21st Nov 2019, 09:45
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Also, doesn’t a heavy A321 rely on flap auto retract during the climb out as a departure in 1+F will exceed the flap limiting speed before its time to clean up ? Obviously once the flaps are in, the higher CONFIG 1 slats only speed limit will apply.
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Old 21st Nov 2019, 10:02
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G-D for 90t is 245 kt under ISA, checked for IAE/Shark and CFM/fence. All the same,

I could imagine Vls being around 230, what is it?
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Old 21st Nov 2019, 11:49
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The ATHR will fly below green dot, but it won't fly below VLS. I haven't flown the 321, but ours are NEOs and have different flap limiting speeds.
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Old 21st Nov 2019, 12:42
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Originally Posted by AerocatS2A View Post

Oh I see. You don’t need to disconnect autothrust to deal with this, you just select a speed below green dot. The autothrust will happily work right down to Vls.
Indeed it will, unfortunately I dont have VLS figures to hand for a heavy 321 but if memory is correct it could be above flap limiting speed. My apologies for confusing things by mentioning green dot. The following is a note from the QRH:

Note: At very high weights, VFE CONF1 is close to VLS clean. To select CONF1, deselect A/THR, decelerate to (or slightly below) VLS and select CONF1 when below VFE. When established at CONF1, the crew can re-engage the A/THR and use managed speed again.

Now I'm not saying that a competent crew can't do that. What I am saying is that it would have been MUCH easier (and safer) to put in some more flap rivets!

There is also the flap auto-retract as mentioned above which is less than ideal. Indeed somwhere in the FCOM they have even put a note saying something along the lines of 'flap overspeed EICAS messges may be disregarded during auto-retraction'
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Old 21st Nov 2019, 13:39
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How many times it did happen, that an MTOW loaded A321 needed an immediate return while A/THR was still operative. And how much extra workload was it for the crew to recycle it.
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