X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-qy0-f179.google.com ([209.85.221.179] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4222776 for flyrotary@lancaironline.net; Thu, 15 Apr 2010 14:02:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.221.179; envelope-from=david.staten@gmail.com Received: by qyk9 with SMTP id 9so1885283qyk.1 for ; Thu, 15 Apr 2010 11:02:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:content-type; bh=GazwUjrrrbpyBxx99/p352zm7XEr16roDGVf3DSpNrI=; b=aTfIywYqczLjSc7xupjpr+CFcEsna/hSJDNf0hBO869loiNpNM2mRtM1aHGkccsFNt cqvecL3i4GK51ZbVWY8WOnWohouOzfXLZA6p0x4eRA0vm8IRo1OxZipcn1Pf2TP1aIHQ s6ayh4FayE6nvN7pGTNPB1aNqxNbZHzCRigFc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=HieWIl9yPUObzXfvA9H93rSsbdHWFh9AbLDS+pTvSBX/HJRFZaLNO7C4GbFStFqX09 bOIAOiVp4kvwvfVQGzeHPDAsYtJSSJA84O33dHxGEAkSFOL7yCeFQ66DhQoFjs2WWz1j tfepGVCk1UpY4w/3+rmABKOv+6NU9q3wkCJ/I= MIME-Version: 1.0 Received: by 10.224.45.197 with HTTP; Thu, 15 Apr 2010 11:02:05 -0700 (PDT) In-Reply-To: References: Date: Thu, 15 Apr 2010 13:02:05 -0500 Received: by 10.224.100.204 with SMTP id z12mr125599qan.20.1271354525462; Thu, 15 Apr 2010 11:02:05 -0700 (PDT) Message-ID: Subject: Re: [FlyRotary] Weird sound during descent From: David Staten To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000feaee4e05dfb47504844a4ab4 --000feaee4e05dfb47504844a4ab4 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Is there any free play in the control surfaces that could cause a flutterin= g of the surface that you dont hear when power/noice is higher? On Thu, Apr 15, 2010 at 10:13 AM, Jeff Whaley wrote: > I have been hearing a weird buzzing sound usually detectable on base leg > at low power settings. It is hard to describe in text but is repeatedly = as > zzuuzz, zzuuzz, zzuuzz . > > I thought it was wind noise escaping between the fuselage and gear legs, = as > there are no fairings between the fuselage and top of the cub-style gear. > > Last night it was bit bumpy and during one descent there was a good bump > that lifted me against the seat belts -- the noise stopped. > > Tracy had cautioned me against low power steeps descents, something about > thrust bearing and/or snubber =96 maybe refresh me on that one Tracy? > > However, an approach speed of 500 fpm, 80 mph, 3000 rpm, mp <10=94, is no= t > what I=92d consider steep. > > > > Anyone care to give me a clue as to what I might be hearing? > > If I get a chance to fly this weekend, I=92ll experiment to see if I can > stop/change the noise with speed or attitude adjustments. > > Jeff > > > __________ Information from ESET NOD32 Antivirus, version of virus > signature database 5031 (20100415) __________ > > The message was checked by ESET NOD32 Antivirus. > > http://www.eset.com > > This message, and the documents attached hereto, is intended only for the > addressee and may contain privileged or confidential information. Any > unauthorized disclosure is strictly prohibited. If you have received this > message in error, please notify us immediately so that we may correct our > internal records. Please then delete the original message. Thank you. > --000feaee4e05dfb47504844a4ab4 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Is there any free play in the control surfaces that could cause a flutterin= g of the surface that you dont hear when power/noice is higher?

On Thu, Apr 15, 2010 at 10:13 AM, Jeff Whaley <jwhaley@datacas= t.com> wrote:

I have been hearing a weird buzzing sound usually de= tectable on base leg at low power settings.=A0 It is hard to describe in te= xt but is repeatedly as zzuuzz, zzuuzz, zzuuzz .

I thought it was wind noise escaping between the fus= elage and gear legs, as there are no fairings between the fuselage and top = of the cub-style gear.

Last night it was bit bumpy and during one descent t= here was a good bump that lifted me against the seat belts -- the noise sto= pped.

Tracy had cautioned me against low power steeps desc= ents, something about thrust bearing and/or snubber =96 maybe refresh me on= that one Tracy?

However, an approach speed of 500 fpm, 80 mph, 3000 = rpm, mp <10=94, is not what I=92d consider steep.

=A0

Anyone care to give me a clue as to what I might be = hearing?

If I get a chance to fly this weekend, I=92ll experi= ment to see if I can stop/change the noise with speed or attitude adjustmen= ts.

Jeff



__________ Information from ES= ET NOD32 Antivirus, version of virus signature database 5031 (20100415) ___= _______

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com

This message, and the d= ocuments attached hereto, is intended only for the addressee and may contai= n privileged or confidential information. Any unauthorized disclosure is st= rictly prohibited. If you have received this message in error, please notif= y us immediately so that we may correct our internal records. Please then d= elete the original message. Thank you.

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