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Mike Whisky
Joined: 05 Jun 2006
Posts: 336
Location: Switzerland
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 Posted: Tue Jul 29, 2014 1:21 pm Post subject: ICAO Noise Test results RV-10 |
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This might not be of great concern of most RV-10 owners especially in the US but I consider this still an important environmental information for all the RV-10 owners.
My RV-10 has been built and accepted under Swiss regulations and one part of it is the noise measurement certificate. Landing tax are based mostly on MTOW plus a charge for the noise class your aircraft is in. So it was of great interest to achieve the lowest noise class.
As there was no data available about noise emission of an RV-10 I want to share my findings.
The main noise sources are the propeller and the engine noise via the exhaust system. As prop tip speed is one factor I decided to go with a smaller diameter 3-blade MT (MTV-12B/193-53) propeller. The next factor is of course RPM which I reduced to max 2500. It is quite common for GA aircraft in Germany or Switzerland to have RPM reduced to 2500 in order to meet the maximal allowed noise requirements. The next thing is the exhaust system/muffler. There are special mufflers available like Liese which are quite common to muffle the noise even further, however I needed my baseline first to make the call to install them or not and to be able to define its required dB reduction.
My RV-10 has the standard Vetterman 6-3 exhaust system and the above called 3-blade prop running max 2500 RPM. The test were conducted at MTOW 2700lb /1225kg.
ICAO Noise Measurement Test Scenario
ICAO Annex 16 Chapter 10
- Application accepted from 1988 onwards
One measurement point
take-off flight path with max. take-off power
Noise measured in dB(A)
The measurement crew on the ground takes a picture of the overflying aircraft to compare the logged overflight altitude reported from the aircraft with the measured results. At the same time it measures the noise. More factors are taken into consideration including wind, surrounding surface etc. I had to conduct 6 flights and the average noise values plus the correcting factors result in the final noise level in dB, which puts me in one of the noise categories mentioned above.
To make a long story short my RV-10 achieved 77.5 dB which falls under category D, which is the lowest available.
It is interesting to note that the only other RV-10, which went through the same test, is equipped with an two place Hartzell propeller (as well reduced to 2500 RPM) and Liese mufflers attached to the Vetterman exhaust pipes, achieved noise class C. Therefore it looks as if the propeller diameter and probably the tip form is a major contributor to noise. There might be other contributing factors such as sound insolation which might work as a reduction of resonance.
For all the builders who are building under a regulation where noise reduction is a topic I hope that might help to consider propeller choice besides looks, ground clearance and weight.
Michael
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_________________
RV-10 builder (flying)
#511 |
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bruce1hwjohnson(at)yahoo.
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| Posted: Tue Jul 29, 2014 2:44 pm Post subject: ICAO Noise Test results RV-10 |
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Another good reason to live in the USofA. Sorry for you Michael
God Bless America
(please) 
Bruce
On Tuesday, July 29, 2014 2:33 PM, Mike Whisky <rv-10(at)wellenzohn.net> wrote:
--> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)>
This might not be of great concern of most RV-10 owners especially in the US but I consider this still an important environmental information for all the RV-10 owners.
My RV-10 has been built and accepted under Swiss regulations and one part of it is the noise measurement certificate. Landing tax are based mostly on MTOW plus a charge for the noise class your aircraft is in. So it was of great interest to achieve the lowest noise class.
As there was no data available about noise emission of an RV-10 I want to share my findings.
The main noise sources are the propeller and the engine noise via the exhaust system. As prop tip speed is one factor I decided to go with a smaller diameter 3-blade MT (MTV-12B/193-53) propeller. The next factor is of course RPM which I reduced to max 2500. It is quite common for GA aircraft in Germany or Switzerland to have RPM reduced to 2500 in order to meet the maximal allowed noise requirements. The next thing is the exhaust system/muffler. There are special mufflers available like Liese which are quite common to muffle the noise even further, however I needed my baseline first to make the call to install them or not and to be able to define its required dB reduction.
My RV-10 has the standard Vetterman 6-3 exhaust system and the above called 3-blade prop running max 2500 RPM. The test were conducted at MTOW 2700lb /1225kg.
ICAO Noise Measurement Test Scenario
ICAO Annex 16 Chapter 10
- Application accepted from 1988 onwards
One measurement point
take-off flight path with max. take-off power
Noise measured in dB(A)
The measurement crew on the ground takes a picture of the overflying aircraft to compare the logged overflight altitude reported from the aircraft with the measured results. At the same time it measures the noise. More factors are taken into consideration including wind, surrounding surface etc. I had to conduct 6 flights and the average noise values plus the correcting factors result in the final noise level in dB, which puts me in one of the noise categories mentioned above.
To make a long story short my RV-10 achieved 77.8 dB which falls under category D, which is the lowest available.
It is interesting to note that the only other RV-10, which went through the same test, is equipped with an two place Hartzell propeller (as well reduced to 2500 RPM) and Liese mufflers attached to the Vetterman exhaust pipes, achieved noise class C. Therefore it looks as if the propeller diameter and probably the tip form is a major contributor to noise. There might be other contributing factors such as sound insolation which might work as a reduction of resonance.
For all the builders who are building under a regulation where noise reduction is a topic I hope that might help to consider propeller choice besides looks, ground clearance and weight.
Michael
--------
RV-10 builder (flying)
#511
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=427526#427526
Attachments:
http://forums.matronics.com//files/test_procedure_133.png
http://forums.matronics.com//files/noise_category_166.png
nbsp; --> http://forums.matronics.com</ -Mat http:/========================
[quote][b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
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gary(at)bendun.net
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| Posted: Wed Jul 30, 2014 3:29 am Post subject: ICAO Noise Test results RV-10 |
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Bruce,
Not very helpful. Michael put some effort into sharing his findings. Why the sour grapes from Uncle Sam?
Sent from my iPhone
On Jul 29, 2014, at 5:40 PM, Bruce Johnson <bruce1hwjohnson(at)yahoo.com (bruce1hwjohnson(at)yahoo.com)> wrote:
[quote]Another good reason to live in the USofA. Sorry for you Michael
God Bless America
(please)
Bruce
On Tuesday, July 29, 2014 2:33 PM, Mike Whisky <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)> wrote:
--> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)>
This might not be of great concern of most RV-10 owners especially in the US but I consider this still an important environmental information for all the RV-10 owners.
My RV-10 has been built and accepted under Swiss regulations and one part of it is the noise measurement certificate. Landing tax are based mostly on MTOW plus a charge for the noise class your aircraft is in. So it was of great interest to achieve the lowest noise class.
As there was no data available about noise emission of an RV-10 I want to share my findings.
The main noise sources are the propeller and the engine noise via the exhaust system. As prop tip speed is one factor I decided to go with a smaller diameter 3-blade MT (MTV-12B/193-53) propeller. The next factor is of course RPM which I reduced to max 2500. It is quite common for GA aircraft in Germany or Switzerland to have RPM reduced to 2500 in order to meet the maximal allowed noise requirements. The next thing is the exhaust system/muffler. There are special mufflers available like Liese which are quite common to muffle the noise even further, however I needed my baseline first to make the call to install them or not and to be able to define its required dB reduction.
My RV-10 has the standard Vetterman 6-3 exhaust system and the above called 3-blade prop running max 2500 RPM. The test were conducted at MTOW 2700lb /1225kg.
ICAO Noise Measurement Test Scenario
ICAO Annex 16 Chapter 10
- Application accepted from 1988 onwards
One measurement point
take-off flight path with max. take-off power
Noise measured in dB(A)
The measurement crew on the ground takes a picture of the overflying aircraft to compare the logged overflight altitude reported from the aircraft with the measured results. At the same time it measures the noise. More factors are taken into consideration including wind, surrounding surface etc. I had to conduct 6 flights and the average noise values plus the correcting factors result in the final noise level in dB, which puts me in one of the noise categories mentioned above.
To make a long story short my RV-10 achieved 77.8 dB which falls under category D, which is the lowest available.
It is interesting to note that the only other RV-10, which went through the same test, is equipped with an two place Hartzell propeller (as well reduced to 2500 RPM) and Liese mufflers attached to the Vetterman exhaust pipes, achieved noise class C. Therefore it looks as if the propeller diameter and probably the tip form is a major contributor to noise. There might be other contributing factors such as sound insolation which might work as a reduction of resonance.
For all the builders who are building under a regulation where noise reduction is a topic I hope that might help to consider propeller choice besides looks, ground clearance and weight.
Michael
--------
RV-10 builder (flying)
#511
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=427526#427526
Attachments:
http://forums.matronics.com//files/test_procedure_133.png
http://forums.matronics.com//files/noise_category_166.png
nbsp; --> http://forums.matronics.comhttp:/========================
| Quote: |
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
"3D"courier" new,courier"="">[url=3D"http://www.matronics.com/Navigator?RV10-List"]http://www.matronics.com/Navigator?RV10-List[/url]
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
//forums.matronics.com
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
ot;">http://www.matronics.com/contribution
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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[b]
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
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Mike Whisky
Joined: 05 Jun 2006
Posts: 336
Location: Switzerland
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| Posted: Wed Jul 30, 2014 3:46 am Post subject: Re: ICAO Noise Test results RV-10 |
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No worries, I guess that Bruce wanted to express is that he is happy to have artificially reduce power to meet noise requirements.
I think however, as I might be the first one who has taken part in an official noise test of this common engine propeller combination for the RV-10, it is a benchmark for all in case it is required.
I recall from the transition training in Florida that there were billboards on the highway complaining about aircraft noise. I guess for every RV-10 owner with the same setup it might be good to know that they can meet the lowest Swiss noise category, by just pulling RPM back a little if the neighborhood is noise sensitive.
Cheers
Mike
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
_________________
RV-10 builder (flying)
#511 |
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| Back to top |
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bruce1hwjohnson(at)yahoo.
Guest
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| Posted: Wed Jul 30, 2014 10:03 am Post subject: ICAO Noise Test results RV-10 |
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Wasn't trying to negative, just stating that I was glad we don't have to do that in the US and sorry that Micheal did..
God Bless America
(please)
Bruce
On Wednesday, July 30, 2014 4:55 AM, Mike Whisky <rv-10(at)wellenzohn.net> wrote:
--> RV10-List message posted by: "Mike Whisky" <rv-10(at)wellenzohn.net (rv-10(at)wellenzohn.net)>
No worries, I guess that Bruce wanted to express is that he is happy to have artificially reduce power to meet noise requirements.
I think however, as I might be the first one who has taken part in an official noise test of this common engine propeller combination for the RV-10, it is a benchmark for all in case it is required.
I recall from the transition training in Florida that there were billboards on the highway complaining about aircraft noise. I guess for every RV-10 owner with the same setup it might be good to know that they can meet the lowest Swiss noise category, by just pulling RPM back a little if the neighborhood is noise sensitive.
Cheers
Mike
--------
RV-10 builder (flying)
#511
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=427537#427537http://www.matronics.com/Navigator?RV10-Lista href="http://forums.matronics.com/" = -->
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
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