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  #11  
Old 04-27-2018, 04:32 PM
NYTOM NYTOM is offline
 
Join Date: Jun 2005
Location: Raleigh, North Carolina
Posts: 1,022
Question European members?

Mufflers are required in a lot of areas in Europe. Someone ( Sport Aviation, flying, etc.) did a story a few years back about flying quiet in Europe. Had a lot of photos of GA aircraft and they were equipped with a long muffler ( at least 3’)
which was attached along the centerline of the belly. I was interested at the time but everyone I talked with over here said why rush it till they were ever required.
Probably be a lot nicer flight as long as the performance of the aircraft wasn’t effected too much. Maybe some of our members from over the pond can chime in.
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  #12  
Old 04-28-2018, 02:10 AM
Raiz Raiz is offline
 
Join Date: Nov 2009
Location: Cambridge, UK
Posts: 53
Default From a European member...

NACA deduced that the propeller noise dominates and that exhaust noise is next in light propeller driven airplanes. Here is a snippet from the summary of this NACA paper:

"Results of this study show that propeller noise dominates engine exhaust noise even though the exhaust noise has a relatively high intensity. It is concluded, therefore, that in order to reduce the outside sound level of an airplane materially, It will be necessary to modify the propeller to operate at low tip speeds and to have a large number of blades. The practical use of this conclusion is a matter of considerable technical complexity involving many compromises. An effective engine exhaust muffler will also be required."

Many European countries charge higher landing fees for noisy aircraft, which drives people to fit smaller diameter propellers (which usually means more blades), propellers that are better damped (wood core or whatever), reduce the maximum propeller RPM (often to 2,500) and fit exhaust mufflers. One supplier of exhaust mufflers is Gomolzig but they are $$$. Another is Liese (also $$$).

EDIT: Forgot to add this "make your own muffler" link.

Also checkout this VAF post - it's about getting a noise certificate on an RV-10 in Switzerland.

Last edited by Raiz : 04-28-2018 at 02:13 AM.
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  #13  
Old 04-28-2018, 08:40 AM
Mike S's Avatar
Mike S Mike S is offline
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Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 14,280
Default Black knob/blue knob?

Rob, you will almost certainly have to take the plane to Lincoln or some other airport to do your phase one------I would be extremely surprised if you get the approval to use your home strip.

Lincoln is great place for first flight/phase I, and after you get comfortable with the plane, mark off the length of your strip and practice takeoff in that distance with the power pulled back, and/or with lower takeoff RPM---- and see what that does for the noise------need someone on the ground for sure to observe/listen.

All you might need may be the black or blue knob------
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  #14  
Old 04-29-2018, 11:27 AM
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Av8rRob Av8rRob is offline
 
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Posts: 204
Default

Thanks for the recommendations everyone
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  #15  
Old 04-29-2018, 11:37 AM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 2,440
Default

Quote:
Originally Posted by Mike S View Post
Rob, you will almost certainly have to take the plane to Lincoln or some other airport to do your phase one------I would be extremely surprised if you get the approval to use your home strip.

Lincoln is great place for first flight/phase I, and after you get comfortable with the plane, mark off the length of your strip and practice takeoff in that distance with the power pulled back, and/or with lower takeoff RPM---- and see what that does for the noise------need someone on the ground for sure to observe/listen.

All you might need may be the black or blue knob------
Mike,
Do you know if the restriction still is removed for Placerville? UP to a few years ago, they would not allow first flight out of KPVF but I believe it was removed.
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  #16  
Old 04-29-2018, 11:50 AM
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Mike S Mike S is offline
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Location: Dayton Airpark, NV A34
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I think Dick W. did his phase 1 with the Moose at PVF------might talk to him.

He is across the taxiway and a few hangars east, now flying a C182 or somesuch.

EAA folks might know also?
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VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #17  
Old 04-29-2018, 02:48 PM
Bavafa Bavafa is offline
 
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Location: Sacramento, CA
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Thanks Mike.
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  #18  
Old 04-29-2018, 07:16 PM
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vernon smith vernon smith is offline
 
Join Date: Jun 2017
Location: Naples FL
Posts: 145
Default

Yes, and in the late fifties, if you really wanted to PO all your neighbor you would put on steel packs, which were nothing more then a slight interruption to a straight exhaust system. Guaranteed to get you a ticket in twenty four hours.

Today, any self respecting dump truck with a Jake Break is a good ten decibels higher without the traffic violation Interesting how societies' expectations and tolerances change over time.
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