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A321 wing area enlargement

Posted: Tue Feb 18, 2020 1:56 pm
by Amiga500
Just had a thought....

The A321 wing area is 122.4 sqm, the flap area is 21.1 sqm[1] and the flaps have a span of ~0.78 of the overall wing span. Which works out at an average chord (not MAC) of around 0.8m.

If:
- the flap track were adjusted such that the first 20% of aft travel were at 0 deg angle of attack
- the spoilers could depress slightly below 0 deg (they already will to an extent for prebow effects)
- Additional shrouds were added to the wing pressure surface (which can be translated forward for conventional flap functionality)

Then overall wing area could be increased by perhaps around 3-3.5% - without carrying that added wetted area when it is of no use.

The A320 flap track mechanism is the right images in [2]; the flap (i) translates down the golden track and (ii) pivots as a result of the rotary action of the flap track motor. The track could be reprofiled (non-straight) to achieve the same max deployment angle (but adjusting intermediate angles) without massive upheaval in the mechanism.

Looking further down the road, completely decoupling aft translation of the flap and rotation of the flap could leave you able to expand wing area by maybe up to 60% of the flap area. In the case of the A320, that would be over 10%!

Again, that would be an extension in wing area that is a pilot deployed option. Are you flying 4000nm at MTOW? Want to get to 40kft quicker? Expand the wing. Are you flying 500nm at weight well below MTOW, then minimise the wing to reduce wetted area.

There would be a weight penalty to the more complex mechanism of course, but its likely on the order of tens of kilos. But your wing loading might drop from (@ TOW 101Tonnes) from ~825 kg/sqm to ~750 kg/sqm. To me, that's worth carrying 100 kg of extra mechanisms.

Might be something we see in the future.


[1] https://booksite.elsevier.com/978034074 ... /table.htm
[2] https://upload.wikimedia.org/wikipedia/ ... 7_A320.png
[3] https://theflyingengineer.files.wordpre ... 1/11/n.jpg

Re: A321 wing area enlargement

Posted: Tue Feb 18, 2020 2:26 pm
by Boeingphan
You sir should be employed by Airbus or Boeing..

Re: A321 wing area enlargement

Posted: Tue Feb 18, 2020 2:37 pm
by AECM
The A321XLR will have a different Flap layout/configuration than the current A321

Re: A321 wing area enlargement

Posted: Tue Feb 18, 2020 2:49 pm
by Noshow
It's very likely that Airbus might add another wing for future stretches and heavier versions beyound the A321XLR. "The old saying" was the A321ceo wing is maxed out already. (But obviously it wasn't.) It would not be overly expensive and could be used by Airbus to target any possible NMA size and market for cheap.

Re: A321 wing area enlargement

Posted: Tue Feb 18, 2020 4:14 pm
by WIederling
@Amiga500.
Interesting.

Been here?
https://www.flightglobal.com/analysis/a ... 41.article
not much more available at the moment.

They seem to want to go towards the more flexible profile "re"forming actuation:

"Like on the A350, we will have intermediate flap positions controlled by the FMS, so instead of just having four fixed positions there will be intermediate settings which will help in the second-segment climb," da Costa says. "In 'Flaps 1' and 'Flaps 2', controlled by the FMS, [depending on weight and other factors], there are intermediate positions – for example a kind of '0.5' and '1.5' setting."

Re: A321 wing area enlargement

Posted: Tue Feb 18, 2020 5:00 pm
by HIA350
Boeingphan wrote:
You sir should be employed by Airbus or Boeing..

agree