How come small planes don't have mufflers?

J

JOERM

Member
Joined
Jul 10, 2003
Messages
906
Reaction score
196
Location
OLYMPIC PENINSULA WA
Always wondered why these planes are not required to have mufflers. They are so loud when they fly over. I don't care about the noise just wondering why they are not required to have a muffler, every thing else does. With the exception of HD's of course. Is it because of weight? Power loss? Fuel mileage? I took a few flying lessons years ago butnever asked the instructor.
 
Register to hide this ad
Are you sure if you are hearing engine noise or prop noise? The tips of a typical single engine aircraft propeller move faster than the speed of sound at maximum RPM and what you may be hearing is the sound of the blades cutting through the air. It's more pronounced on takeoffs. It sounds kinda like an angry weedeater. If this is what you are hearing, unfortunately there isn't much that be done about that. It's the nature of the beast.
 
Last edited:
Some have mufflers, some don't. Some have augmenters that act to quiet the exhaust while reducing drag.

As noted, the prop noise is usually louder than the exhaust.
 
Along with the prop noise, many of these planes are equipped with multiple carburetors, which can make a lot of noise as well.
 
Years ago someone built a experimenta electric plane. You guesed it. It was about as loud as a regular one.

One type of plane was actually banned from certain airports about 10 years ago because it was so loud. One of its design features was really fast spinning props.

Ed
 
While I have owned several small planes I must admit I never really gave it deep thought before this! Somehow I think part of the reason might have something to do with the hazzard of a leaking muffler gassing you. It would be hugely magnified with the higher altitude.
Along with that the weight and bulk of a muffler would certainly be a drawback. Payload is a huge factor and you wouldnt want the muffler in the cabin with you, things are as tight as possible under the coweling, and it would create extra drag and impeed performance hung on the exterior.
 
Every small plane I have ever seen or flown has had a muffler. That is how most cabin heaters get their heat to warm the cockpit. Without a heater a high altitude it get pretty cold. During takeoff and climb out the props are usually turning at max RPM and that is what generates the loud noise. At altitude the prop turns around 2000 rpm, + or -, and are much quieter.

It also depends on where you are sitting. Sitting inside the cockpit airplane noise is a good thing, sitting in your house watching TV, not so much..........
 
You must log in or register to reply here.

Similar threads

chief38
I HAVE BEEN GOING BACK AND FORTH FOR 7 YEARS ABOUT BUYING THIS KNIFE - DECISION MADE!
2 3
Replies
42
Views
2K
Chubbs103
C
Retired W4
Cessna 560 Crashes
2 3
Replies
49
Views
2K
Retired W4
Retired W4
chief38
THE LAST 2 WEEKS HAVE BEEN MAINTENANCE WORLD FOR ME - LOL
Replies
17
Views
2K
LVSteve
LVSteve
RM Vivas
The value of gun books
Replies
15
Views
708
dobegrant
dobegrant
RM Vivas
NYPD - M&P #S812894 - How I Research The NYPD Guns
Replies
17
Views
1K
RM Vivas
RM Vivas

Latest posts

Back
Top