From: Sky2high@aol.com
Message-ID: <9d5bd6b2.24bd835a@aol.com>
Date: Wed, 14 Jul 1999 02:08:26 EDT
Subject: LNC2 Sound deadening/management.
To: lancair.list@olsusa.com
Mime-Version: 1.0

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I have installed the EAR Lancair 320 Sound deadening material (15-20 lbs) and 
get readings of  102 to 105 (Db) on the "C" scale at 180Kt cruise at the head 
level (some time back, I hope I am using the right terminology).  This is, of 
course, with the old canopy 1/8 inch thickness.  My Corvette (hard top on) 
reads 95 Db at head level at 75 MPH (the extra speed of the Lancair is worth 
the extra noise).

Most of the noise comes from the prop/wind thru the canopy.  The next highest 
noise source is the pilot side NACA air vent.  

Remember to stuff something (or noise deaden) the D-section of the stub wing, 
otherwise, it acts like the sound box on a guitar.  I would also recommend 
sound-deadening of the firewall and the floor above the exhaust back to the 
seat.  This should weigh a lot less than 15 pounds.

I cock my ears to those of you flying with the 3/16 inch canopy.  It has got 
to be quieter.

BTW, I use Model 1 Bose headsets, combined with hearing loss due to age and 
tinnitus, makes for a quiet environment enhanced by the purring machinations 
of a Lycoming IO 320 and the panoramic view of rapidly passing scenery seen 
thru my astigmatism correcting, silvered, mono-chromatic bi-focals.  (I think 
that's the longest  sentence I ever wrote)

Scott Krueger
N92EX

PS,  My ANR Lightspeed 20 does not work very well in my open-air Challenger 
(Not the jet, the tube and fabric lightplane).

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