On Fri, 15 Jul 2005 02:20:37 GMT, David Findlay
wrote:

I'm in the early stages of the homebuilding disease :-P and still don't
know exactly what I want to build, just that I want to build something.
I'm interested to know what people have done in their aircraft to reduce
the interior noise level? Can such noise insulation be added to plan or
kit built aircraft without too much difficulty? Is it possible to reach
car or commercial airline jet noise levels in a homebuilt? Thanks,

David

There's a LOT you can do to reduce noise in the cockpit. Most of it
has to do with proper use of insulating materials but there are other
things like taking extreme care in sealing things like doors and
windows. Using double panes in the side windows will help. Using a
thicker plexiglass for the windshield makes a difference and adds
value in bird strike protection. Putting an effective muffler on the
engine will help too. All this costs money and adds weight.

I recently added two mufflers to my V-6 engine mounted on the test
stand because I thought the neighbors would object to the very loud
barking of the headers while I ran it for extended periods. The
mufflers cut the exhaust noise to a muted burble, but the prop is
sounding loud now even though I haven't had it beyond 1,500 rpm yet.
I won't be able to use the mufflers in the airplane because they are
too big to fit. They are also too heavy. But there are other
mufflers that I could use that are much more slender and lighter when
the time comes to install the engine in the fuselage for good.

Corky