That Pesky old issue, Noise!

[Eye Can't Fly]

Yeah, I have a PM sent to him over at the other place. One of the local clubs here in Sk. has a 85dB level, I know of some electric planes that wouldn't pass at that field!



EDIT: Here is a MAAC Zone Directors reply:





I have usually seen it done with the plane sitting on the ground. Run up to full throttle. Measurements are usually taken with a sound meter. The one meter is usually held at 3 feet above the ground. Quite often from the side at 90 degrees to the plane. Distance from the plane varies from club to club. Some are 3 meters. Some are 15 ft.... that part varies. There are no hard and fast rules.

I have also seen measurements taken from the side, front and back and then averaged out.



So basically an long established organization that knows that fields are being lost every of noise, has no standard for testing. Hmmmm

 

[Super08]

That is low, it would be very hard to meet.

 

[Eye Can't Fly]

Super08;2102 wrote: That is low, it would be very hard to meet.

Well you know how that goes, bunch of crusty old guys that started flying shortly after the Wright Bros....... and refuse to accept the changes! Hey, its their club, they can do what they want!

 

[Pbilt024]

Eye Can't Fly;2104 wrote: Well you know how that goes, bunch of crusty old guys that started flying shortly after the Wright Bros....... and refuse to accept the changes! Hey, its their club, they can do what they want!

It's been said a thousand times with motorcycles, stereo systems, etc "If it's too loud, you're too old!"

 

[Super08]

Eye Can't Fly;2104 wrote: Well you know how that goes, bunch of crusty old guys that started flying shortly after the Wright Bros....... and refuse to accept the changes! Hey, its their club, they can do what they want!

Jeff told me about a couple of clubs he has run into like that.

 

[jtec-radiowave]

Noise is an issue if we want to keep our fields. Being in the noise business you would be shocked how many different ways it tested if at all and the I don't care how noisy my plane is. The AMA has guidelines but each club can dictate there own noise requirements. The problem comes in the testing.



To my knowledge I have never know anyone to have a calibrated ear to take noise measurements. Next would be I've got my Radio Shack un calibrated DB meter and I am not sure how it works but it says your too loud. See I placed it here in my gut and got the reading ( I use to be a QA engineer in the aerospace industry. calibration is everything)



Guidelines for testing is an open space ( no buildings around or anything that reflects noise like a group of trees, cars, etc.) at a dictated height, several spots around the aircraft ( I don't have the rules in front of me ) AMA is basically testing at 3 meters (10ft) 98DB over hard surface, 96DB over grass. IMAC is at 25ft. Really we should be testing frequency. If its out of the audible hearing range or close you should be good!!



The problem is what may be accepted at you home field won't when you visit a different field. There is enough crap going on with the so called drones we don't need to bring more attention to our planes no matter what the size, We ALL need to address noise. I know most modern designs now have pipe tunnels or room in the cowl for a decent muffler or canister. Use a good prop not one that flexes when you throttle up. Get the RPM down. The higher the RPM the more noise that is generated by the tip speed of the prop and exhaust. Reducing RPM reduces noise

 

[Eye Can't Fly]

Well stated! Your response leaves me with one little question, what is a "QA Engineer"?



The newbies in IMAC tend to show up with whatever plane they own. Lots of them are old school with stock mufflers. A lot of the lower end planes don't have tunnels. Prop selection and throttle management are sometimes the only two options.

 

[Super08]

Quality Assurance

 

[Eye Can't Fly]

I e-mailed the Club I was at for their testing method. I got the response last night. The plane is measured at full throttle by a Radio Shack meter ~24" (60cm) off the ground, 10' (3M) on each side of the center line of the fuse at the CG point, and front and back 3M on either end of the CG. They do not average the four meter readings. Anything testing over 96dB is grounded until it is 95dB or less.



Neither one of the plane I took could pass the test at these distances and were both over at the tail, and each one was over on one or the other wing reading. However, both averaged 96dB or less. This test wasn't conducted with the Radio Shack (#------) meter. Guys I am one of those noisy guys! (according to some).



Edit: The Canadian organization (MAAC) at present does not have a standard method (protocol) for testing noise of RC planes. I believe this inhibits people from travelling to fly at other clubs. Trust me, there is no joy in making a trip and having to turn around and come home. I have the ear of one of the MAAC Noise Committee members.



Not being a noise expert (other than 34 years of nagging from the wife) what would be a useful protocol for a standard noise test? I'm all ears!

 

[Eye Can't Fly]

Talked to two of the Zone Directors for MAAC about the organization not having a Standard testing Method for noise. While they got what I was asking for, the rest of the BOD did not. As noise tolerance is a unique issue to each and every club setting a Maximum dB level has to be left with the clubs. I get that. Why are they so reluctant to have a Standard way of testing.



Seems some thought the cost would be too high for the Association or the individual clubs. Oh well, I tried. Small wonder few (relative to the size of the organization) people travel to fly outside their home club.....



Guess this issue can be put to rest.