X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 23 May 2008 11:15:05 -0400 Message-ID: X-Original-Return-Path: Received: from web36907.mail.mud.yahoo.com ([209.191.85.75] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with SMTP id 2933011 for lml@lancaironline.net; Wed, 21 May 2008 21:49:57 -0400 Received: (qmail 22732 invoked by uid 60001); 22 May 2008 01:49:43 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type:Message-ID; b=Q8FPqc8SP2ktgsQeP44+ctmVMCmLwU928NWU64z8DbkAK+SF3Xy3NhdPx8r8JicX9j6+Qh7VEEs0M42p05JTLiHAT42urw/L5w8ClpUw09QTMKx4YkFEVuqU5TYeu02aaTD7R4WQ/gyTAR4HqDY4CmY2/hnn8DKwsjBzECbL1KQ=; X-YMail-OSG: P6pKw0gVM1m5x3ZgPoPH86PuCPsvm7x3CaPiWpaSM1usKTB20uCwdAqXs8ePqZv98Xpg0T2B44pHG4SBcq0cByyh6bqIPA3wnwKXCF.b3NMn_UtSoG7STyKGFl_kwafnKz6UgxsiRhRICt7G.4Xjeim_eRrDt6dGt35R1CjpmCR3xMvCpg-- Received: from [209.225.225.232] by web36907.mail.mud.yahoo.com via HTTP; Wed, 21 May 2008 18:49:43 PDT X-Mailer: YahooMailRC/975.23 YahooMailWebService/0.7.185 X-Original-Date: Wed, 21 May 2008 18:49:43 -0700 (PDT) From: Chris Zavatson Subject: Re: [LML] Re: Fuel Testing X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-2084733708-1211420983=:21916" X-Original-Message-ID: <212048.21916.qm@web36907.mail.mud.yahoo.com> --0-2084733708-1211420983=:21916 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Jim,=0A<>=0AThe actual scenario was this.=A0 =0AThe=A0de= livery truck, with 1,000 gal of Jet A still loaded, fills up with 8,000 gal= of Avgas.=A0 The 9,000 gal mixture is added to whatever was left in the st= orage tank at the FBO.=A0 A week or two later the=A0delivery truck returns = with another 8,000 gal. of Avgas and adds it to tank at the FBO.=A0=A0The s= tarting concentration is about 11%.=A0 The actual concentration gets dilute= d every time more Avgas is added and when the =0Ablend is added to whatever= is left in the=A0aircraft fuel tank.=A0 It took three weeks before the sou= rce of emerging engine troubles was traced to contaminated=A0Avgas.=0AThe= =A0engines that received close to 11%=A0 almost came apart in flight,=A0res= ulting in a few emergency landings.=A0 I received something up to 5%.=A0 My= engine did not shed metal but still took a beating.=A0 The bearings were s= meared and the exhaust valve seats were blue.=A0 Avoiding non-catastrophic = engine damage will require a reliable=A0method of detecting very low levels= of contamination.=A0 =0AChris=A0=0AChris Zavatson=0AN91CZ=0AL360std=0Awww.= N91CZ.com=0A=0A=0A=0A --0-2084733708-1211420983=:21916 Content-Type: text/html; charset=us-ascii
Jim,
<<It seems unreasonable to me that anyone would ever have a Jet A contamination as low as 10%.>>
The actual scenario was this. 
The delivery truck, with 1,000 gal of Jet A still loaded, fills up with 8,000 gal of Avgas.  The 9,000 gal mixture is added to whatever was left in the storage tank at the FBO.  A week or two later the delivery truck returns with another 8,000 gal. of Avgas and adds it to tank at the FBO.  The starting concentration is about 11%.  The actual concentration gets diluted every time more Avgas is added and when the
blend is added to whatever is left in the aircraft fuel tank.  It took three weeks before the source of emerging engine troubles was traced to contaminated Avgas.
The engines that received close to 11%  almost came apart in flight, resulting in a few emergency landings.  I received something up to 5%.  My engine did not shed metal but still took a beating.  The bearings were smeared and the exhaust valve seats were blue.  Avoiding non-catastrophic engine damage will require a reliable method of detecting very low levels of contamination. 
Chris 
 
Chris Zavatson
N91CZ
L360std

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