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DocLightning
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A320 Whine On Approach

Sat Aug 11, 2012 6:46 pm

I have noticed that I can very easily ID A320-series aircraft when they are on final approach by sound alone. They make a strange "harmonic" whining noise as they pass overhead. No other aircraft makes this noise on approach.

The noise is made by all A320-series aircraft to my knowledge, regardless of engine option. I have never heard it on climb-out.

Is it made by a certain flaps setting? Does anyone know?
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RE: A320 Whine On Approach

Sat Aug 11, 2012 7:37 pm

I have also heard the same sound - it definitely seems to be more of an aerodynamic warble than an engine noise. My initial impression would be flaps as well.
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RE: A320 Whine On Approach

Sun Aug 12, 2012 11:55 am

You're not going to believe this, but I actually think it's the underwing retractable landing lights.
AND (see? I have something to backup my opinion!) I think this because when I fly on A320s, I can hear the landing lights being extended on final. And they make a distinct noise. You can easily tell when they're on, particularly on approaches at night, because you can see the light reflecting on the cowl.

And it makes a distinct aerodynamic noise.

The 737NG has a similar design for retractable lights, but they're mounted to the fuselage belly, rather than under the wing in the wing-body fairing area. And I don't hear it on a 737 like I do an A320.


So, I've noticed it too, and I'm sticking to my guns- I think it's the extended landing lights.
 
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zeke
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RE: A320 Whine On Approach

Sun Aug 12, 2012 12:09 pm

I think the higher frequency sound heard as the aircraft approaches is a Doppler effect from the engines.
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RE: A320 Whine On Approach

Sun Aug 12, 2012 5:35 pm

Quoting AA737-823 (Reply 2):
I think this because when I fly on A320s, I can hear the landing lights being extended on final. And they make a distinct noise.

That is very true, I have noticed that too. I am always listening for the noises of flaps, gear etc and this one confused me a little until I figured it out. It certainly changes the noise inside the cabin..
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RE: A320 Whine On Approach

Mon Aug 13, 2012 1:09 am

Quoting AA737-823 (Reply 2), "when I fly on A320s, I can hear the landing lights being extended on final."

I'm not familiar with procedures at other carriers, but at Delta, on the A-320/A-319 fleet, the landing lights are extended as the aircraft descends through 10,000 feet AGL. This is to increase aircraft visibility in the low altitude environment. Therefore, the landing lights are on well before the aircraft is on final approach.

Similarly, the landing lights normally remain on until climbing through 10,000 feet AGL.

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RE: A320 Whine On Approach

Mon Aug 13, 2012 2:12 am

Quoting e38 (Reply 5):
I'm not familiar with procedures at other carriers, but at Delta, on the A-320/A-319 fleet, the landing lights are extended as the aircraft descends through 10,000 feet AGL. This is to increase aircraft visibility in the low altitude environment. Therefore, the landing lights are on well before the aircraft is on final approach.

Similarly, the landing lights normally remain on until climbing through 10,000 feet AGL.

Isnt that mandatory for all operating aircraft around the world?
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DocLightning
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RE: A320 Whine On Approach

Mon Aug 13, 2012 5:32 am

Quoting e38 (Reply 5):
I'm not familiar with procedures at other carriers, but at Delta, on the A-320/A-319 fleet, the landing lights are extended as the aircraft descends through 10,000 feet AGL. This is to increase aircraft visibility in the low altitude environment. Therefore, the landing lights are on well before the aircraft is on final approach.

I have heard this noise well before final approach. Today I was under the approach path for SFO and I noticed a few things. 1) Yes, only A320's make this noise. 2) It starts very suddenly. You can hear the lights (assuming that's what makes the noise) extending.

I also spent some time under the departure path and I hear the same noise (a few miles away from the airport... about five miles north, actually), which I hadn't noticed before.
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RE: A320 Whine On Approach

Mon Aug 13, 2012 8:13 pm

Quoting DocLightning (Thread starter):
The noise is made by all A320-series aircraft to my knowledge, regardless of engine option.

True, but the CFMs can be heard under that whine more so than the IAEs can, which leads me to suspect that the landing-light theory is a good one because the nacelles are different.
 
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longhauler
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RE: A320 Whine On Approach

Mon Aug 13, 2012 9:45 pm

The landing lights would be extended well before approach. It would be more than 30 miles out, descending through 10,000 feet, as noted above.

Their noise is distinct and certainly noticeable, but it is more of a "rumble" from the disturbed airflow than a "whine".

Quoting LH707330 (Reply 8):
which leads me to suspect that the landing-light theory is a good one because the nacelles are different.

Except that the extendable landing lights are not near the nacelles. If the whine is more noticeable on the CFMs than the IAEs then likely it is engine fan harmonics.
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RE: A320 Whine On Approach

Mon Aug 13, 2012 11:16 pm

Quoting longhauler (Reply 9):
Except that the extendable landing lights are not near the nacelles. If the whine is more noticeable on the CFMs than the IAEs then likely it is engine fan harmonics.

Maybe the engines just sound different and the IAE sounds closer to the whine, because they both have it but the CFM you can also hear a bit of jet noise.
 
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RE: A320 Whine On Approach

Tue Aug 14, 2012 12:21 am

Quoting longhauler (Reply 9):
Except that the extendable landing lights are not near the nacelles. If the whine is more noticeable on the CFMs than the IAEs then likely it is engine fan harmonics.

I have noticed that VX's A320's (CFM) make the exact same noise as UA's (IAE).
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RE: A320 Whine On Approach

Tue Aug 14, 2012 7:54 am

It's amazing how 2 different engine types can sound so similiar - at least on approach - otoh it makes it almost impossible to tell the CFMs from the IAEs on an approaching A32X; but the good thing is you don't even have to crane your neck to identify the aircraft.

I wonder what it is exactly that makes the -5A's on approach ring so differently from the other CFM56 - variants, and why the V2500 have almost the same sound signature - again on approach. I'm sure there is a technical explanation but I'm no expert alas...
 
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RE: A320 Whine On Approach

Wed Aug 15, 2012 3:47 pm

Quoting longhauler (Reply 9):
Their noise is distinct and certainly noticeable, but it is more of a "rumble" from the disturbed airflow than a "whine".

Indeed, and it is quite noticeable if you are sitting overwing on an A320-series when they get extended. I also don't think the sound (I like to call it a UFO whine LOL) is attributed to the lights especially when its taken into consideration that other aircraft have lights like these and they don't have that whine (although the placement of these lights does vary).

The A320-series definitely has a distinct sound to it. I live out in West Babylon, Long Island. When the 22s are in use at JFK, there is a plane over my house every 2 minutes (sometimes less) at ~4000 - ~5000 feet as they make their way north from the ocean towards the northern part of LI before turning for the 22s (love it when the big boys fly over, always nice to see the A380, A346, B744   ). I can always tell when an A320-series is going overhead with that lovely "UFO whine" and it really does seem to be something more with the engine, possibly the fan blades. I do notice a bit of a difference though, the V2500 seems to be a little more on the quiet side as they go over, I'm thinking that may have to do with the C.N.A. on the that engine.
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RE: A320 Whine On Approach

Wed Aug 15, 2012 4:23 pm

Quoting B6JFKH81 (Reply 13):
I can always tell when an A320-series is going overhead with that lovely "UFO whine" and it really does seem to be something more with the engine, possibly the fan blades.

I guarantee it isn't, because on approach they don't make the noise and then suddenly there is a rumble like something being extended and then the noise starts.
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RE: A320 Whine On Approach

Wed Aug 15, 2012 5:31 pm

Quoting DocLightning (Reply 14):
I guarantee it isn't, because on approach they don't make the noise and then suddenly there is a rumble like something being extended and then the noise starts.

Okay, more to the puzzle.

Gear being extended? That certainly causes a lot of rumble.
Perhaps flaps being extended further?

Or it could be the resulting increase in engine noise with the extension of the above. Remember, the "A320 engine buzz" on take off is a result of high power combined with low speed. (I think it sounds like sitting between a pair of Evinrudes). But to a lesser extent than on take-off, with the extension of gear and flaps, the low speed/higher power occurs again.
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RE: A320 Whine On Approach

Wed Aug 15, 2012 6:31 pm

Quoting longhauler (Reply 15):
Gear being extended? That certainly causes a lot of rumble.
Perhaps flaps being extended further?

The "UFO whine" noise exists well before the gear gets extended as I hear it when they go over my house which is about 20 miles from JFK (as the crow flies) and aircraft still have quite a ways to go. Not sure what setting the flaps are at when they pass over though, my guess is minimal setting at best as I really don't see flaps get dropped until we are getting close to turning final (based on the flights I've been on).
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RE: A320 Whine On Approach

Wed Aug 15, 2012 7:46 pm

Quoting B6JFKH81 (Reply 16):
The "UFO whine" noise exists well before the gear gets extended

   you are talking about the sudden-onset whine that drops rapidly in pitch and morphs into the regular sound of an airplane flying overhead, right?

Quoting DocLightning (Reply 7):
2) It starts very suddenly. You can hear the lights (assuming that's what makes the noise) extending.

It starts very suddenly, but it's probably not related to any deployment event because it always starts with the same angle between the plane of the fans and the line of sight of the observer. Try paying attention to that next time, and you'll hear/see what I mean.
 
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RE: A320 Whine On Approach

Wed Aug 15, 2012 7:48 pm

Quoting e38 (Reply 5):
I'm not familiar with procedures at other carriers, but at Delta, on the A-320/A-319 fleet, the landing lights are extended as the aircraft descends through 10,000 feet AGL. This is to increase aircraft visibility in the low altitude environment. Therefore, the landing lights are on well before the aircraft is on final approach.

Well, yeah... hence a person standing on the approach path can hear it!!!  
But thanks for your detailed explanation as to why we use landing lights on airplanes. You must be a pilot!


I'm sticking with my answer- it's landing lights.
 
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RE: A320 Whine On Approach

Wed Aug 15, 2012 9:12 pm

Quoting WingedMigrator (Reply 17):
It starts very suddenly, but it's probably not related to any deployment event because it always starts with the same angle between the plane of the fans and the line of sight of the observer. Try paying attention to that next time, and you'll hear/see what I mean.

No, because I've heard it stop just as suddenly when the aircraft was heading towards me on climb-out. "ShuuuuUUUUUUP!" and then it sounds like a 737.
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RE: A320 Whine On Approach

Wed Aug 15, 2012 9:32 pm

Quoting WingedMigrator (Reply 17):
you are talking about the sudden-onset whine that drops rapidly in pitch and morphs into the regular sound of an airplane flying overhead, right?

Negative, it is a harmonic sound that changes pitch really only due to the dopplar effect as it passes over (higher pitch as it comes towards you, lower pitch as it moves away from you). It's not sudden-onset, and at the altitude they pass over my house while on approach (4000 to 5000 feet) that harmonic sound actually does stay louder than the engine rumble (especially on the V2500-equipped birds). I have been trying to find some footage online but I'm not finding any that really represent the harmonic whine that I am referencing, I may have to take my own vid if I have time/effort. I think I am referencing a different "whine" than the OP.
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RE: A320 Whine On Approach

Thu Aug 16, 2012 3:40 am

I guess it's hard to use words to describe sounds with any accuracy...
 
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RE: A320 Whine On Approach

Thu Aug 16, 2012 4:52 am

Quoting DocLightning (Reply 19):
No, because I've heard it stop just as suddenly when the aircraft was heading towards me on climb-out. "ShuuuuUUUUUUP!" and then it sounds like a 737.

I think that might be a wind-related thing, where the sound waves stack up, so you hear a faint sound, then the rapidly descending noise followed by the normal 737/A320 etc. noise.
 
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RE: A320 Whine On Approach

Sun Aug 19, 2012 2:09 am

The A320-series "UFO whine" is also evident on climbout. I notice it more when the airplane is several thousand feet up, as its not being drowned out by as much actual engine noise.
The Airbus narrowbodies (especially the one 30 seconds into the footage) on approach in this video perfectly demonstrate the noise:

http://www.youtube.com/watch?v=8g0TWFUDDtE

This sound definitely isn't caused by the flaps being lowered as most aircraft in this video are in clean configuration. I've always been curious about the cause of this sound; seems to be aerodynamically related rather than engine related since the sound is the same regardless of if its CFM or IAE-equipped.

[Edited 2012-08-18 19:19:49]
 
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RE: A320 Whine On Approach

Tue Sep 04, 2012 1:48 am

I can distinguish that particular sound of the Airbus, and I believe its RR engines are the root cause. And speaking of noise, I love the 757's fitted with RRoyce engines, another easily ID roar! The old 747's made a music for the ear take off sound, I think it was double the number of 757 engines, anyone?
 
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RE: A320 Whine On Approach

Tue Sep 04, 2012 4:58 am

Just tonight while walking my dog I was thinking about the cause of this very noise as a A320 passed overhead. It's an interesting theory on the landing lights. However, this sound seems to be limited to the A320 family, wouldn't a similar sound be heard on the A300s with similar lights?


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DocLightning
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RE: A320 Whine On Approach

Thu Sep 06, 2012 9:43 pm

Quoting 747fan (Reply 23):
This sound definitely isn't caused by the flaps being lowered as most aircraft in this video are in clean configuration. I've always been curious about the cause of this sound; seems to be aerodynamically related rather than engine related since the sound is the same regardless of if its CFM or IAE-equipped.

I will note that in the video you reference, the A320 is in a clean configuration (or at least a very low flaps setting) but yet it has the landing lights out. The landing lights are mounted near the fuselage.

The other thing is that all of the A320's that make the whine appear to have the leading edge slats extended. Perhaps THAT's the sound? Even at the lowest flaps setting the leading edge slats will extend. A long, narrow slit like the space between the slat and the leading edge will certainly whistle if conditions are right.

Quoting ogshelly (Reply 24):

I can distinguish that particular sound of the Airbus, and I believe its RR engines are the root cause.

As we have said, the sound is not dependent on engine type. A320's do not have an RR engine option, per se. There is CFM and IAE. IAE does have some RR involvement.

Quoting RyDawg82 (Reply 25):

Just tonight while walking my dog I was thinking about the cause of this very noise as a A320 passed overhead. It's an interesting theory on the landing lights. However, this sound seems to be limited to the A320 family, wouldn't a similar sound be heard on the A300s with similar lights?

It may be a quirk that is specific to the A320 fuselage shape and the specific placement of the landing lights (assuming that they are the cause). Whatever it is, I wonder if Airbus knew about it in advance of construction?
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RE: A320 Whine On Approach

Wed Apr 01, 2015 3:52 pm

Quoting DocLightning (Reply 26):
Whatever it is, I wonder if Airbus knew about it in advance of construction?

I wouldn't know whether they were aware of it in advance of construction or not, but really wish that they would somehow eliminate it seeing as that they must know about it now. If we all notice it and descriptions of it aren't exactly favorable, I'm guessing it would be fair to assess this as a drawback to their design. I don't mind the sound of jet aircraft in general at all. In fact I like it and find it soothing unless it is a 747 at less than 2000' above my building, which then becomes a bit alarming due to the sheer volume of it.ls noise. For whatever reason, I'm just not a fan of the harmonic "UFO whine" of an A320 family jet. It is downright annoying In my opinion.

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Bambel
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RE: A320 Whine On Approach

Wed Apr 01, 2015 7:46 pm

 
wn676
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RE: A320 Whine On Approach

Wed Apr 01, 2015 8:45 pm

Quoting Bambel (Reply 28):
This noise is alleeady taken care of:http://www.euractiv.com/sections/avi...-device-cuts-aircraft-noise-303505b.

   You beat me to it by an hour...I'd always heard that the fuel vents are what causes this noise, hence why you hear it on both CFM- and IAE-powered versions of the A320 family. I grew up in central Phoenix always hearing this overhead; at that particular location arrivals and departures are in their clean config which seems to match up with what this article describes. Would kind of hate to see it mitigated as it's always been somewhat of a comforting sound, but I'm probably in the minority with that opinion...
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KELPkid
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RE: A320 Whine On Approach

Wed Apr 01, 2015 8:47 pm

Download a sound recording app for your phone and record it as the plane flies by, then post the resulting file to a file sharing service.

I think I know the sound you are talking about, I've heard it before at my house (~25 statute miles due south of PDX), and usually when the aircraft are on the TMBRS1 arrival...
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Sinlock
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RE: A320 Whine On Approach

Wed Apr 01, 2015 9:35 pm

What your all most likely hearing is the high speed air passing over the fuel tank venting outlet. Last year DLR German Aerospace presented a vortex generator device to modify the airflow.
It was tested on an Lufthansa A320 (F-AIUB) when it was still wearing the Airbus factory Reg # F-AUBN.


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Link to article about the Mod.

http://www.euractiv.com/sections/avi...-device-cuts-aircraft-noise-303505

(edited to add link)

[Edited 2015-04-01 14:38:53]
 
AA737-823
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RE: A320 Whine On Approach

Wed Apr 01, 2015 11:56 pm

You guys DO realize that you've resurrected a three-year-old thread, right?
 
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RE: A320 Whine On Approach

Thu Apr 02, 2015 12:37 am

Quoting wn676 (Reply 29):
Would kind of hate to see it mitigated as it's always been somewhat of a comforting sound, but I'm probably in the minority with that opinion...

I don't mind the sound of the air flowing past the fuel tank vent outlet, that actually sounds kind of cool! It is the general whiny high pitched harmonic sound of the A320 family that just gets very old after hearing it dozens and dozens of times a day.

Quoting AA737-823 (Reply 32):
You guys DO realize that you've resurrected a three-year-old thread, right?

I sure do. The issue at hand remains relevant.

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RE: A320 Whine On Approach

Thu Apr 02, 2015 2:07 am

Quoting AA737-823 (Reply 32):
You guys DO realize that you've resurrected a three-year-old thread, right?

It would be courteous to mention it when a years-old thread is resurrected.
 
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RE: A320 Whine On Approach

Thu Apr 02, 2015 6:17 am

It's odd. I feel as if I hear this noise more when the flaps are out...
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seahawk
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RE: A320 Whine On Approach

Thu Apr 02, 2015 7:03 am

The noise is caused by the underwing circular pressure equalisation vents for the fuel tanks. Vortex generators to remove the noise have been developed and LH is rolling them out fleet wide. And I can confirm they work.

http://www.lufthansagroup.com/en/pre...2014/february/12/article/2797.html

With sound files:

http://www.lufthansagroup.com/en/the...the-future/technical-upgrades.html
 
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longhauler
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RE: A320 Whine On Approach

Thu Apr 02, 2015 12:53 pm

Quoting DocLightning (Reply 35):
It's odd. I feel as if I hear this noise more when the flaps are out...

I always thought the same thing. I figured it was some interaction between the flaps/slats and wing/airframe.

Likely though, it is just that "perfect" speed that causes the noise. (Like blowing over a beer bottle). If that speed were the same every time, then flap position would depend on aircraft weight. Sometimes extended, sometimes not.
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RE: A320 Whine On Approach

Thu Apr 02, 2015 2:28 pm

Quoting seahawk (Reply 36):
http://www.lufthansagroup.com/en/pre...2014/february/12/article/2797.html

With sound files:

http://www.lufthansagroup.com/en/the...the-future/technical-upgrades.html

Well, that's annoying. I won't be able to impress my friends by saying: "That's an A320 going over" without even looking up anymore.
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RE: A320 Whine On Approach

Thu Apr 02, 2015 7:08 pm

Quoting DocLightning (Reply 38):
Well, that's annoying. I won't be able to impress my friends by saying: "That's an A320 going over" without even looking up anymore.

Maybe it will be just new build birds getting this at the factory. The noise isn't so loud that I think anyone's noise ratings are in jeopardy here in the US   I'd love to know how much weight and drag the fix imposes...
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RE: A320 Whine On Approach

Fri Apr 03, 2015 2:20 am

Quoting Viscount724 (Reply 34):

Quoting AA737-823 (Reply 32):
You guys DO realize that you've resurrected a three-year-old thread, right?

It would be courteous to mention it when a years-old thread is resurrected.

I'll keep that in mind in the future. I thought it was appropriate enough to just comment on an older thread as opposed to simply generating a nearly identical new thread. Maybe mentioning it would be beneficial to some.

Quoting DocLightning (Reply 38):
Quoting seahawk (Reply 36):
http://www.lufthansagroup.com/en/pre...2014/february/12/article/2797.html

With sound files:

http://www.lufthansagroup.com/en/the...the-future/technical-upgrades.html

Well, that's annoying. I won't be able to impress my friends by saying: "That's an A320 going over" without even looking up anymore.

That's awesome! The difference between the two is like night and day! When I previously read about this I thought that the vortex generators would eliminate the WHOOOOOSH sound the A320 family make at around 3500' on approach here at ORD which was detailed in this thread:
Explain Curious 737 Engine Noise Overhead. (by 26point2 Dec 7 2014 in Tech Ops)

I guess I'm happy to hear that it is the more annoying harmonic whirring sound that is being eliminated by the vortex generators, and not the cooler sound that you hear less often, whatever causes that I'm still not sure. I'm hoping other carriers operating the A320 follow suit, and that maybe Airbus makes these a standard feature on future models.

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RE: A320 Whine On Approach

Fri Apr 03, 2015 3:31 am

Quoting OMP777X (Reply 40):
I'll keep that in mind in the future. I thought it was appropriate enough to just comment on an older thread as opposed to simply generating a nearly identical new thread. Maybe mentioning it would be beneficial to some.

Don't worry about it. Most people mention that it's a bump. All the posts are time/date stamped for a reason, though.

Quoting OMP777X (Reply 40):
That's awesome! The difference between the two is like night and day!

Well, it definitely answers part of my question. But I sometimes suddenly hear the sound start when the A320 is on approach, or hear it stop when they are on climbout, so it doesn't answer my question of whether the flaps might not help with it.
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RE: A320 Whine On Approach

Fri Apr 03, 2015 2:18 pm

The vortex generators are standard equipment on ALL new A320 family aircraft deliveries and have been for close to a year now. However, every A320 I hear, still makes the noise...
 
Thenoflyzone
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RE: A320 Whine On Approach

Fri Apr 03, 2015 3:17 pm

Dont all aircraft have these fuel pressure valves? How come the A320 series is the only one making that noise?

[Edited 2015-04-03 08:18:30]
us Air Traffic Controllers have a good record, we haven't left one up there yet !!
 
Sinlock
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RE: A320 Whine On Approach

Fri Apr 03, 2015 8:31 pm

Quoting thenoflyzone (Reply 43):
Dont all aircraft have these fuel pressure valves? How come the A320 series is the only one making that noise?

It just boils down to the vent being in the perfect location. If it were at a slightly different angle or location the conditions for the harmonic would not exist.
Much like when you blow across a bottles top. A slight change in the distance, pressure, or angle you blow at, and the sound does not happen.

I think a better question would be, Why has it taken over 27 years for this annoyance to be resolved.
In an age of Stage 3 or quieter aircraft I'm sure the A320 howl has started more than a few people down the path of being a vocal airport hating NIMBY activists.
 
OMP777X
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RE: A320 Whine On Approach

Fri Apr 03, 2015 8:53 pm

Quoting Sinlock (Reply 44):

I think a better question would be, Why has it taken over 27 years for this annoyance to be resolved.
In an age of Stage 3 or quieter aircraft I'm sure the A320 howl has started more than a few people down the path of being a vocal airport hating NIMBY activists.

I think that is a valid point. I never really noticed it as much until the new 10C-28C opened up at ORD and I began hearing A320 family jets on approach to 28C over a hundred times a day on most days. It slowly built up on my nerves as opposed to listening to 100+ 737 series jets flying over without making that high pitch tone.

I'm still puzzled as to what causes the deeper descending tone that makes a whhooooooouuusshhhh sound when they come overhead. Again, that sound is much less annoying, and sounds deeper like if you blow over a wine bottle instead of a beer bottle, and only lasts a few seconds. It also seems to only happen on A320 series jets at around 4000'-3500' coming in on approach. Maybe that is related to the flaps being extended?

Best,

OMP777X
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LH707330
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RE: A320 Whine On Approach

Fri Apr 10, 2015 4:56 pm

Damn, now I'll have to find a new unique A320 sound to pick them apart. Regarding the NIMBYs, I'm not sure many realize it until they pay attention. Once I taught my friends to ID a 320 they could all do it, but before nobody cared, "it just sounds like a plane." What I've noticed is that CRJ700s and 900s have a similar tone, but it's a deeper pitch, like a mix of the 320 howl and the PW4090 vacuum-cleaner sound. I wonder if it's got a similar cause.
 
Egerton
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RE: A320 Whine On Approach

Sat Apr 11, 2015 9:47 am

I found this in a "Ten steps to reduce noise by summer 2015" by Heathrow Airport Ltd.

The popular Airbus A320 family of aircraft accounts for 55 to 60% of the aircraftin the skies above Heathrow.
They’re efficient aircraft but they emit a distinctive high pitched whistling soundwhen they’re about 10 to 25
miles from touchdown. It’s now possible to retrofit a component that reduces the noise from each aircraft by
around 6 decibels.

We will encourage our airlines to adopt the new technology – especially those with large A320 fleets.
To make retrofitting a more attractive option, we’ll investigate what incentives – financial or otherwise – we can offer our airlines.

(In our neck of the woods, 6 decibels is a huge amount of noise.)

http://www.heathrowairport.com/stati.../PDFs/heathrow_noise_blueprint.pdf

[Edited 2015-04-11 02:48:45]
 
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winterlight
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RE: A320 Whine On Approach

Sat Apr 11, 2015 4:36 pm

Clear off, HAL. I like this A320 whistle/whine.
Question everything. Trust no-one.
 
OMP777X
Posts: 435
Joined: Fri Jan 23, 2015 8:10 am

RE: A320 Whine On Approach

Tue Apr 14, 2015 5:09 am

Quoting LH707330 (Reply 46):
Damn, now I'll have to find a new unique A320 sound to pick them apart.

 
Quoting winterlight (Reply 48):
I like this A320 whistle/whine.


I don't mind it so much during the daytime, but as night falls and I've already heard dozens throughout the day, I begin to despise it! (especially since the 737 purrs right on by much quieter and mostly goes unnoticed)

  
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