Return-Path: Sender: (Marvin Kaye) To: lml@lancaironline.net Date: Thu, 22 Jul 2004 23:11:48 -0400 Message-ID: X-Original-Return-Path: Received: from imo-d05.mx.aol.com ([205.188.157.37] verified) by logan.com (CommuniGate Pro SMTP 4.2b8) with ESMTP id 331141 for lml@lancaironline.net; Thu, 22 Jul 2004 21:56:02 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.157.37; envelope-from=Newlan2dl@aol.com Received: from Newlan2dl@aol.com by imo-d05.mx.aol.com (mail_out_v37_r2.6.) id q.86.113d5274 (18403) for ; Thu, 22 Jul 2004 21:55:27 -0400 (EDT) From: Newlan2dl@aol.com X-Original-Message-ID: <86.113d5274.2e31ca0f@aol.com> X-Original-Date: Thu, 22 Jul 2004 21:55:27 EDT Subject: Re: [LML] Re: Legacy-Noise Barrier under Rudder Pedals X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1090547727" X-Mailer: 9.0 for Windows sub 5032 -------------------------------1090547727 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Actually, a LOT of noise comes through the floor and through the nose wheel well. The NWW is only a very thin layer of composite so it transmits noise very easily. On Dave Morss' plane, we eliminated most of the noise by insulating the floor, nose wheel well and behind the firewall. Additional absorbers were placed on the glare shield and sidewalls but the floor and firewall were the big noise makers. I built barrier blankets that fit tightly behind the firewall using a glass/.5 lb /sq. ft. barrier sheet/foam blanket. For the floor (which is opposite the exhaust remember), I used a 1/4" fire retardant felt/.5 lb barrier and another felt. This went under the floor mats. the aircraft was very noticably quieter after the floor mats were in. I suspect there may be more aerodynamic noise coming in via the main spar so if you were to pull out the seats and make a very tightly fitting felt/barrier/felt blanket over that, I suspect it would be quieter still. Dan Newland -------------------------------1090547727 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Actually, a LOT of noise comes through the floor and through the nose w= heel well.  The NWW is only a very thin layer of composite so it transm= its noise very easily.  On Dave Morss' plane, we eliminated most of the= noise by insulating the floor, nose wheel well and behind the firewall.&nbs= p; Additional absorbers were placed on the glare shield and sidewalls but th= e floor and firewall were the big noise makers.  I built barrier blanke= ts that fit tightly behind the firewall using a glass/.5 lb /sq. ft. barrier= sheet/foam blanket.  For the floor (which is opposite the exhaust reme= mber), I used a 1/4" fire retardant felt/.5 lb barrier and another felt.&nbs= p; This went under the floor mats. the aircraft was very noticably quieter a= fter the floor mats were in.  I suspect there may be more aerodynamic n= oise coming in via the main spar so if you were to pull out the seats and ma= ke a very tightly fitting felt/barrier/felt blanket over that, I suspect it=20= would be quieter still.
 
Dan Newland
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