Mufflers and Airplanes

[jollyroger]

When I lived in Germany I took an intro flight, but didn't get my license until I got back into the states, however I distinctly remember the cessna 152 having a muffeler attached to it to keep it quieter. I know they have catagories of noise certificates and landing becomes cheeper the more quiet your plane is.

I guess the question is why don't we do this here. Especially since there are so many neighbors that have complained and are trying to close airports. Wouldn't something like that be a friendly gesture? Do the mufflers cause a signifigant power decrease. I've seen cars that have muffler systems removed have less power than high performance muffler systems. So why not?

 

[Skip Miller]

When I lived in Germany I took an intro flight, but didn't get my license until I got back into the states, however I distinctly remember the cessna 152 having a muffeler attached to it to keep it quieter. I know they have catagories of noise certificates and landing becomes cheeper the more quiet your plane is.

I guess the question is why don't we do this here. Especially since there are so many neighbors that have complained and are trying to close airports. Wouldn't something like that be a friendly gesture? Do the mufflers cause a signifigant power decrease. I've seen cars that have muffler systems removed have less power than high performance muffler systems. So why not?

I think the answer is that the propeller makes the most noise on an airplane. You can achieve a lot more noise reduction by just reducing power as soon as it can be safely done. Note that fixed pitch props on climbout never get to full rpm anyway. You can tell a constant speed prop ship from a fixed pitch prop easily when they are at full power on the takeoff run.

Why don't we do it here? For the same reason we don't fly the noise abatement procedures that currently exist. Now some of us do, but it will only take one bad apple to spoil the barrel, if I may use that analogy. Voluntary compliance by less than 100% of the aircraft will not solve the problem.

-Skip

 

[gismo]

Airplane noise reductions on certified aircraft require FAA approval which means lots of testing and dollars. Many designs do have mufflers and some newer ones have derated engines (lower RPM limits) specifically to address noise. But in general, GA airplanes don't have to meet any standards noise wise in the US.

 

[JohnR]

No one here wants to spend the money or lose the useful load just to make a handful of whiners on the ground happy. Especially when they'll just find something new to whine about. People like that are never satisfied anyway.