Heathrow - Noise Reduction
Couldonlyaffordafiver
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Good stuff. He must have been to Rhein Main as well then!
Admittedly, I think it was used there for different reasons although I don't ever recall using it myself, despite having been there a zillion times after it was introduced.
Admittedly, I think it was used there for different reasons although I don't ever recall using it myself, despite having been there a zillion times after it was introduced.
Ohcirrej
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As much as I miss the old girl, does anybody else see the irony of a thread about LHR noise and Speedbird002 
Seriously though, it was discussed a bit here
But I do actually have a question for our pilot guys and gals reference the whole idea. How will it effect minimum runway occupancy time, especially during really busy sequences and ATC need jets off the runway ASAP?
Seriously though, it was discussed a bit here
But I do actually have a question for our pilot guys and gals reference the whole idea. How will it effect minimum runway occupancy time, especially during really busy sequences and ATC need jets off the runway ASAP?
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no !!! surely not, landing further down the runway ??? just a publicity stunt, no self respecting pilot would allow that, idiotic managers again i'll wager ? it's about time they found something that generates cash to do !!!
incidently, is it already policy at luton ?? what, over the fields on 26 ?? maybe abit quieter for the sheep !!!, have yet to see anything on the airport plates that tells me to land a 767 further down a 6808' runway !!!
incidently, is it already policy at luton ?? what, over the fields on 26 ?? maybe abit quieter for the sheep !!!, have yet to see anything on the airport plates that tells me to land a 767 further down a 6808' runway !!!
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This can't be correct surely? The only way to organise it would be to displace the threshold, along with the PAPIs and ILS/DME.
At LHR it may not be too bad, but at smaller airlields the greatly increased risk would be unjustifiable, just to add a few feet to the flight path of a LANDING aircraft.
I don't know where he got the idea that this is policy at Luton, perhaps he's watched the odd Cessna land well down the runway to save taxy time.
Clearly a glittering career in airline management is awaiting this young man.
At LHR it may not be too bad, but at smaller airlields the greatly increased risk would be unjustifiable, just to add a few feet to the flight path of a LANDING aircraft.
I don't know where he got the idea that this is policy at Luton, perhaps he's watched the odd Cessna land well down the runway to save taxy time.
Clearly a glittering career in airline management is awaiting this young man.
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Can 140 feet make that much difference to the noise footprint? I seriously doubt it. And did that guy properly research the implications, some of which have been mentioned here and on another thread? Again, I doubt it. Either the ILS glidepath has to be moved or ATC procedures might have to be revised to take account of some aircraft flying 140 ft above expected altitudes.
How about changing the the glidepath angles on the main runways to 3.5. That way aircraft over London would be considerably more than 140 ft higher... What effect would that have on normal aircraft operations?
How about changing the the glidepath angles on the main runways to 3.5. That way aircraft over London would be considerably more than 140 ft higher... What effect would that have on normal aircraft operations?
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At LHR it may not be too bad, but at smaller airlields the greatly increased risk would be unjustifiable, just to add a few feet to the flight path of a LANDING aircraft.
I guess it would need each runway to have two ILSs - but that should be manageable. Just ensure that they have clearly distinguishable idents (unlike IRR, ILL and IAA!).
UkEng
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The plan is to move the ILS (glideslope only) beam to accomadate. Anyone living in close to the threshold will no doubt benefit even if it is only 140ft.
Having said that I live about 10 miles from Heathrow and you lot still make a right racket flying overhead
Having said that I live about 10 miles from Heathrow and you lot still make a right racket flying overhead
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UK Eng, you are right.
I just spent several days with friends who live on the north side of Clapham Common. This seems to be the point many arrivals for the south runway are vectored to intercept final. Although I have flown over it many times, I was not prepared for how annoying it is on the ground to have an aircraft pass overhead every 60 seconds or so. It is like having someone vacuuming in the room above for hours on end. Not deafening, but very annoying.
When I overflew the area I followed the recommended noise reduction profiles, but I did not fully appreciate how much noise an aircraft produces even at 3 thousand ft or more, especially on a still day.
My friends bought the house having viewed it on a day when wind etc made the noise much less noticeable, and they thought they could live with it. They are now having second thoughts.
I am sure that any noise reductions achieved for whatever reasons valid or specious, will be appreciated.
I just spent several days with friends who live on the north side of Clapham Common. This seems to be the point many arrivals for the south runway are vectored to intercept final. Although I have flown over it many times, I was not prepared for how annoying it is on the ground to have an aircraft pass overhead every 60 seconds or so. It is like having someone vacuuming in the room above for hours on end. Not deafening, but very annoying.
When I overflew the area I followed the recommended noise reduction profiles, but I did not fully appreciate how much noise an aircraft produces even at 3 thousand ft or more, especially on a still day.
My friends bought the house having viewed it on a day when wind etc made the noise much less noticeable, and they thought they could live with it. They are now having second thoughts.
I am sure that any noise reductions achieved for whatever reasons valid or specious, will be appreciated.
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HEATHROW DIRECTOR,
The only thing that will be able to tell there is less noise is the monitors. No human can tell the difference in loudness of 2 events that are within a dB or two of each other, only a computer can. A 747 that is 140 ft higher may have noise reduction of maybe a dB. Unless it is an RR powered one.............
ZQA297/30,
At 3000 ft most aircraft are pretty quiet and will not be heard in a closed up house. You may notice some of the louder ones when outside doing yardwork or womething. There is a slight difference between an aircraft on approach and one on takeoff.
The only thing that will be able to tell there is less noise is the monitors. No human can tell the difference in loudness of 2 events that are within a dB or two of each other, only a computer can. A 747 that is 140 ft higher may have noise reduction of maybe a dB. Unless it is an RR powered one.............
ZQA297/30,
At 3000 ft most aircraft are pretty quiet and will not be heard in a closed up house. You may notice some of the louder ones when outside doing yardwork or womething. There is a slight difference between an aircraft on approach and one on takeoff.
Trent900 - THINK BIG
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A possibly more likely glide slope/STAR/SID phenomenon in Europe proposed....
A possibly more likely glide slope/STAR/SID phenomenon in Europe proposed....
A more likely phenomenon from recent discussions at EBACE, Geneva in May et al from the European Aviation Safety Agency affecting glide slope approaches into main European hubs in the future will be the complete removal of low altitude holding patterns, entry points etc. The proposed long term goal described is to effectively go the other way on the glide slope:
i.e. simplify class airspace; produce high altitude entry points with a/c going down a theoretical glide slope at say FL250 (and way beyond/above that FL) at a 3 degree approach before joining the real glide slope lower down. (Long haul would join the slope at a lot higher up than local or short haul traffic). This would, as was argued, produce a 1 line straight-in approach in and out of airports.
- At least that’s the theory proposed for a simpler approach to landing and I wouldn’t be surprised to SID’s as well as STAR’s
….But knowing how quick & dynamic most of our EU governmental institutions are, I can’t see this happening for at least 10 years.
I appreciate that this is different to the above proposed BA issue at EGLL but reducing lower altitude a/c from circling, hopefully is a more realistic approach to keeping the "noise down" than a shift of 140ft as well as more fuel management friendly too.
Apologies, if this is all old hat.
Kind regards,
EGLD0624 (@ 4.5 degree approaches.)
A more likely phenomenon from recent discussions at EBACE, Geneva in May et al from the European Aviation Safety Agency affecting glide slope approaches into main European hubs in the future will be the complete removal of low altitude holding patterns, entry points etc. The proposed long term goal described is to effectively go the other way on the glide slope:
i.e. simplify class airspace; produce high altitude entry points with a/c going down a theoretical glide slope at say FL250 (and way beyond/above that FL) at a 3 degree approach before joining the real glide slope lower down. (Long haul would join the slope at a lot higher up than local or short haul traffic). This would, as was argued, produce a 1 line straight-in approach in and out of airports.
- At least that’s the theory proposed for a simpler approach to landing and I wouldn’t be surprised to SID’s as well as STAR’s
….But knowing how quick & dynamic most of our EU governmental institutions are, I can’t see this happening for at least 10 years.
I appreciate that this is different to the above proposed BA issue at EGLL but reducing lower altitude a/c from circling, hopefully is a more realistic approach to keeping the "noise down" than a shift of 140ft as well as more fuel management friendly too.
Apologies, if this is all old hat.
Kind regards,
EGLD0624 (@ 4.5 degree approaches.)
Last edited by egld0624; 27th Jul 2004 at 20:23.
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747FOCAL - I agree entirely and my posting about 3.5 glidepaths wasn't wholly serious. Watching the Farnborough Air Show my wife and I both commented on the difference between modern jets and those of yesteryear - VC-10, BAC-11, 707, etc. The overall noise is very considerably less now than it was in those days so it's difficult to know what would be needed to appease the anti-noise lobby.
UkEng
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747FOCAL - you're quite right about the noise. I rarely notice them anymore when buttoned up inside my hovel but being summer and all that we have the doors and windows open a lot.
Not complaining though seeing as i'd be out of a job without them but I am glad to see the back of the flying pencil - now that was loud windows open or shut
I scoffed at first seeing BA's proposals but unless it's all spin and hot air I really can't see any disadvantages...
Not complaining though seeing as i'd be out of a job without them but I am glad to see the back of the flying pencil - now that was loud windows open or shut
I scoffed at first seeing BA's proposals but unless it's all spin and hot air I really can't see any disadvantages...
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Coincidentally I spent the weekend staying just north of Clapham Common as well. The noise is almost continuous throughout the day, but within about 10 hours you get used to it. It certainly didn't disturb me lying in bed in the mornings and I had all the windows open.
In fact, according to my hosts, the best thing about the "long, pointy thing" was that it broke up the monotony of 747s/777s/330s rumbling across all day by providing something worth looking at!
In fact, according to my hosts, the best thing about the "long, pointy thing" was that it broke up the monotony of 747s/777s/330s rumbling across all day by providing something worth looking at!
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Sound, in a similar manner to light, is subject to an inverse square law.
This means that the intensity of a sound at a given level 'L' at distance 'X' from the source will be level 'L/4' at distance '2*X'.
Sound intensity and power however are also measured using a logarithmic scale; therefore 90dB is ten times greater than 80dB.
Since we are talking about a phase of flight that involves heights of 0-3000ft and a nett difference of 140ft on any part of the glide over the course of an approach, it seems that the suggestion would only have any noticable effect towards the final part of the approach.
The following calculates the difference, in dB, between the 'reference' sound (at current heights) and indicates the reduction obtained at the proposed heights. (I have rounded the difference in heights involved up to 150ft)
At the start of the final approach phase the difference between 3000ft (factor '1') and 3150ft (factor '0.91') is quite small.
intensity reduction=10log(0.91/1); result=-0.4dB
However, Taking the end of the final approach and landing phase; 300ft (factor '1') and 450ft(factor '0.44') the difference is rather more substantial.
reduction=10log(0.44/1); result=-3.6dB
Nevertheless, even such a reduction, AT OR CLOSE TO DECISION HEIGHT, would be only just noticable to human hearing under standard conditions, while ignoring any other ambient noise.
As we all know the area around EGLL would of course be perfectly silent if it were not for the aircraft (Yeah; right<vvvbg>).
Intensity Reduction Summary:
3000/3150ft : -0.4dB
2500/2650ft : -0.5dB
2000/2150ft : -0.6dB
1500/1650ft : -0.8dB
1000/1150ft : -1.2dB
500/650ft : -2.3dB
300/450ft : -3.6dB
A Quick Quote:
"As a general rule of thumb, depending on the sensitivity of the listener, most people will perceive a 3dB improvement as just noticeable, a 5-6dB improvement as very noticeable and an 8-10dB difference easily a halving of the sound level."
©Custom Audio Designs 2000
I would suggest that ulterior motives are examined and dissected.
Please correct me if I'm wrong
This means that the intensity of a sound at a given level 'L' at distance 'X' from the source will be level 'L/4' at distance '2*X'.
Sound intensity and power however are also measured using a logarithmic scale; therefore 90dB is ten times greater than 80dB.
Since we are talking about a phase of flight that involves heights of 0-3000ft and a nett difference of 140ft on any part of the glide over the course of an approach, it seems that the suggestion would only have any noticable effect towards the final part of the approach.
The following calculates the difference, in dB, between the 'reference' sound (at current heights) and indicates the reduction obtained at the proposed heights. (I have rounded the difference in heights involved up to 150ft)
At the start of the final approach phase the difference between 3000ft (factor '1') and 3150ft (factor '0.91') is quite small.
intensity reduction=10log(0.91/1); result=-0.4dB
However, Taking the end of the final approach and landing phase; 300ft (factor '1') and 450ft(factor '0.44') the difference is rather more substantial.
reduction=10log(0.44/1); result=-3.6dB
Nevertheless, even such a reduction, AT OR CLOSE TO DECISION HEIGHT, would be only just noticable to human hearing under standard conditions, while ignoring any other ambient noise.
As we all know the area around EGLL would of course be perfectly silent if it were not for the aircraft (Yeah; right<vvvbg>).
Intensity Reduction Summary:
3000/3150ft : -0.4dB
2500/2650ft : -0.5dB
2000/2150ft : -0.6dB
1500/1650ft : -0.8dB
1000/1150ft : -1.2dB
500/650ft : -2.3dB
300/450ft : -3.6dB
A Quick Quote:
"As a general rule of thumb, depending on the sensitivity of the listener, most people will perceive a 3dB improvement as just noticeable, a 5-6dB improvement as very noticeable and an 8-10dB difference easily a halving of the sound level."
©Custom Audio Designs 2000
I would suggest that ulterior motives are examined and dissected.
Please correct me if I'm wrong
Last edited by mocoman; 28th Jul 2004 at 03:54.
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Not sure about your math there at the end. I believe the 0.4 dB at 3000 ft, but I think it would remain constant all the way down.
Most human better be able to tell the difference between 2 events that have 3 dB difference or they need to get their ears checked.
I agree with you though, the reduction gained for the increased risk of buying the street if you run over is not worth it. Me suspects there is more to this than meets the eye.
Most human better be able to tell the difference between 2 events that have 3 dB difference or they need to get their ears checked.
I agree with you though, the reduction gained for the increased risk of buying the street if you run over is not worth it. Me suspects there is more to this than meets the eye.
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To change the focus slightly.
Are displaced thresholds a rarity? I seem to recall both JFK and MIA having significantly displaced thresholds on at least one runway each.
In fact, does not MIA conduct LAHSO operations on a runway with a displaced threshold? ( The old 9R that intersects 12) Its been a while so I could be wrong.
Are displaced thresholds a rarity? I seem to recall both JFK and MIA having significantly displaced thresholds on at least one runway each.
In fact, does not MIA conduct LAHSO operations on a runway with a displaced threshold? ( The old 9R that intersects 12) Its been a while so I could be wrong.
Next sim session lesson plan includes the Kasan (kaisan?) C130 style approach.
Seriously, maybe, BAA should evaluate (at cost) purchasing the affected properties according to Db levels. 80Db would get 80% of the cost of their house paid for, 90db = 90% and so on. The further out the lower the level of purchase price. Some people would then get back a substantial reimbursement of their home, yes I must say there would be some draw backs, but the overall cost would be significantly lower than all of the public enquiries and consultation papers put together.
Having lived very close to LHR and even listened to the rantings of HACAN once (nearly ended in bloodshed between themselves) I can say a certain individual has dug himself a huge cesspit and can't get himself out of it without losing face. HE will keep on and on until he gets his way or is on his way.
Oh, by the way, I used to live 2 miles south of LHR and on easterly ops, all the Compton departures used to clatter over my house at around 1500ft, beautiful, low and very noisy, now I live 10miles west and 5 miles south, different levels and I still love it.
Seriously, maybe, BAA should evaluate (at cost) purchasing the affected properties according to Db levels. 80Db would get 80% of the cost of their house paid for, 90db = 90% and so on. The further out the lower the level of purchase price. Some people would then get back a substantial reimbursement of their home, yes I must say there would be some draw backs, but the overall cost would be significantly lower than all of the public enquiries and consultation papers put together.
Having lived very close to LHR and even listened to the rantings of HACAN once (nearly ended in bloodshed between themselves) I can say a certain individual has dug himself a huge cesspit and can't get himself out of it without losing face. HE will keep on and on until he gets his way or is on his way.
Oh, by the way, I used to live 2 miles south of LHR and on easterly ops, all the Compton departures used to clatter over my house at around 1500ft, beautiful, low and very noisy, now I live 10miles west and 5 miles south, different levels and I still love it.
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@747FOCAL
I understand your scepticism; probably 'cos I didn't explain properly.
Let's assume that your aircraft, at 160kts landing configuration is measured at 120dB at 200ft away from the measuring device.
Therefore at 400ft (double the distance) away the sound level will be 1/4 of the level at 200ft.
As I indicated the dB scale is a log scale therefore a reduction factor of 4 in sound level would only equate to a reduction of 6dB; meaning a reading of 114dB at 400ft from the aircraft.
However, move the measuring tool to a distance of 600ft from the aircraft and now you have a sound level that is 1/9th of that measured at 200ft; giving a dB reduction of around 9.5dB and a reading of 110.5dB on the equipment.
What I was trying to convey was the fact that, as you continue down the glide, the difference between the 'old-rules' altitude and the 'proposed-new-rules' altitude remains constant; but that the difference (I used 150ft in my example) becomes a greater proportion of the distance to the measuring equipment (punters or residents included) as you descend.
Therefore the difference in sound levels between the existing and proposed approach paths WILL increase as you approach the notional threshold.
However, as I wrote earlier, the only folks to knowingly benefit (...maybe
) from such a reduction (in sound-level terms) would have to be VERY close to the runway threshold.
I understand your scepticism; probably 'cos I didn't explain properly.
Let's assume that your aircraft, at 160kts landing configuration is measured at 120dB at 200ft away from the measuring device.
Therefore at 400ft (double the distance) away the sound level will be 1/4 of the level at 200ft.
As I indicated the dB scale is a log scale therefore a reduction factor of 4 in sound level would only equate to a reduction of 6dB; meaning a reading of 114dB at 400ft from the aircraft.
However, move the measuring tool to a distance of 600ft from the aircraft and now you have a sound level that is 1/9th of that measured at 200ft; giving a dB reduction of around 9.5dB and a reading of 110.5dB on the equipment.
What I was trying to convey was the fact that, as you continue down the glide, the difference between the 'old-rules' altitude and the 'proposed-new-rules' altitude remains constant; but that the difference (I used 150ft in my example) becomes a greater proportion of the distance to the measuring equipment (punters or residents included) as you descend.
Therefore the difference in sound levels between the existing and proposed approach paths WILL increase as you approach the notional threshold.
However, as I wrote earlier, the only folks to knowingly benefit (...maybe
) from such a reduction (in sound-level terms) would have to be VERY close to the runway threshold.
Last edited by mocoman; 30th Jul 2004 at 01:39.