X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 11 May 2012 00:04:49 -0400 Message-ID: X-Original-Return-Path: Received: from nm25-vm0.bullet.mail.ne1.yahoo.com ([98.138.91.73] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with SMTP id 5531009 for lml@lancaironline.net; Thu, 10 May 2012 08:35:37 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.91.73; envelope-from=charliekohler@yahoo.com Received: from [98.138.90.50] by nm25.bullet.mail.ne1.yahoo.com with NNFMP; 10 May 2012 12:35:02 -0000 Received: from [98.138.88.233] by tm3.bullet.mail.ne1.yahoo.com with NNFMP; 10 May 2012 12:35:02 -0000 Received: from [127.0.0.1] by omp1033.mail.ne1.yahoo.com with NNFMP; 10 May 2012 12:35:02 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 329612.16903.bm@omp1033.mail.ne1.yahoo.com Received: (qmail 9090 invoked by uid 60001); 10 May 2012 12:35:02 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=1gEfSGlBuMmTZwzKJnh0BCLgKp7Bkk3F4i5B0O8cDjWxepDH5ZBip2PqjrGeT2dSE3Re+rYcm3aPhYV6xCG+JckLLobQG4zvn9LkQsmMnoYQMG9O+CPNUw6VHgAU2sdZ4xpnpK4kRlxR7M8WLZid41iQXfyoQsgXGfsAGEHRBOM=; X-YMail-OSG: SvS0wWEVM1lUK7usZwr0Rxao_133ERKqtDfK8OeRm8nXyNd Ll1ykbSJoqmac_bNWciKJEIw0aV_.vo3qiQy6waM.ClaoI0aPzmox.Z7DotZ bkrHkiG7AMTKwzYfqjbuLb9TcqTVXIarSViz2n7rYAOARuGY1SaTGF_8HGLS tbrlFESagxy7NFpSR1upeEw8g3auPu2Z7jybfs.usntVIv__AuHSQ43GmBCJ 1VTAZiU9fvVWEIcxXvZ7pdUxR1Jd9KZyvj95yttKNR2GRibNhKoi1P9WG8IH VxeUq4GGPLclPu56_PTjYwNOZJCaaP6nBZh.hGZtaBabs7dJBNMVrPrVJ2vS Xl85IRXvgD_baa7BGs2ywhSzc.fpzIhjdq60HDFeZCGhLtMavr2a9Hc0_Te2 uHBZNqYV2kguDAVDCkOAHPBwL3ceSywYu0qE92LiM4l3OA3FbKMliTeX7irn y_Y3rCNIY7LNPCeV1dyDSz5BeFaHVC.ky4ec6ke6ruceSraSqLRFAxx1Nwjj BRI2.ozBmQLi_cGwZNkQVjPo5mGeN8sGExwp7AS_DqA-- Received: from [72.189.192.203] by web126002.mail.ne1.yahoo.com via HTTP; Thu, 10 May 2012 05:35:02 PDT X-Mailer: YahooMailWebService/0.8.118.349524 References: X-Original-Message-ID: <1336653302.83799.YahooMailNeo@web126002.mail.ne1.yahoo.com> X-Original-Date: Thu, 10 May 2012 05:35:02 -0700 (PDT) From: Charlie Kohler Reply-To: Charlie Kohler Subject: Re: [LML] Re: Necessity of A/C in IV-P? X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-1915680061-1875361907-1336653302=:83799" ---1915680061-1875361907-1336653302=:83799 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hamid says---=0A=0A"All that the flying installations indicate is that no o= ne has done =0Aanything in their aircraft that has led to the airframe fail= ing due to =0Athe modifications. Maybe there is enough margin that it has n= ot =0Acompromised safety at all. Maybe it has cut deeply into the safety = =0Amargin and there have been a lot of very close calls that no one has =0A= known about.=A0 Without a real engineering analysis taking the big picture = in mind, no one really knows."=0A=0AI disagree;=0A=0AIn these turbulent wea= ther encounters and other unexplained accidents, the full science of accide= nt investigation rarely goes into determining the initial point of failure.= Often the ensuing damage by fire--or impact--or removal -- damages wreckag= e to the point that an accurate determination cannot be made. =0AAnd, as an= aside---I would be interested in knowing the level of expertise the invest= igators have in regards to composite, homebuilt aircraft structures. =0A=A0= So Hamid --I do not believe you can make a statement regarding "No one has= done anything that has led to the airframe failing due to modifications." = without taking into account accidents that have not been adequately examine= d by properly qualified investigators. For those that have the potential fa= ilure at some lower point of stress/Flutter onset than expected. This is on= e of the reasons why Harry's accident is so troubling. Investigators cannot= use a canned explanation. =0A=0AI do agree wholeheartedly with Hamid's sta= tement that real engineering analysis is required. Most would agree (depend= s upon which dog you have in the fight??)" , but point is, who's going to d= o it? =0A=0A=A0=0ACharlie K.=0A=0ASee me on the web at =0Awww.Lancair-IV.co= m=0A=A0=0A=0A=0A________________________________=0A From: Hamid Wasti =0ATo: lml@lancaironline.net =0ASent: Wednesday, May 9, 2012 1:= 38 PM=0ASubject: [LML] Re: Necessity of A/C in IV-P?=0A =0ATed Noel wrote:= =0A> 3. Flight testing with a competent test pilot.=0A> =0A> I think #3 is = best since it deals with the variabilities of the installation and creates = a hard VNE number.=0ADoes it? How much margin do you have? Testing is inten= ded to validate engineering analysis, not to substitute it.=0A=0A> Also, th= ere are a lot of A/C installations flying. This implies a degree of safety.= =0ADoes it? How does your installation compare to the flying installations?= How much safety margin do they have and how much will you have? How far ha= ve they pushed their airframe (intentionally and unintentionally) and how f= ar will you push yours?=0A=0AAll that the flying installations indicate is = that no one has done anything in their aircraft that has led to the airfram= e failing due to the modifications. Maybe there is enough margin that it ha= s not compromised safety at all. Maybe it has cut deeply into the safety ma= rgin and there have been a lot of very close calls that no one has known ab= out.=A0 Without a real engineering analysis taking the big picture in mind,= no one really knows.=0A=0ARegards,=0A=0AHamid=0A=0A--=0AFor archives and u= nsub http://mail.lancaironline.net:81/lists/lml/List.html ---1915680061-1875361907-1336653302=:83799 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hamid says---
"All that the flying installations indicate is that no one has done =0Aany= thing in their aircraft that has led to the airframe failing due to =0Athe = modifications. Maybe there is enough margin that it has not =0Acompromised = safety at all. Maybe it has cut deeply into the safety =0Amargin and there = have been a lot of very close calls that no one has =0Aknown about.  W= ithout a real engineering analysis taking the big picture=0A in mind, no on= e really knows."

I disagree;
In the= se turbulent weather encounters and other unexplained accidents, the full s= cience of accident investigation rarely goes into determining the initial p= oint of failure. Often the ensuing damage by fire--or impact--or removal --= damages wreckage to the point that an accurate determination cannot be mad= e.
And, as an aside---I would be interested in knowing the level of exp= ertise the investigators have in regards to composite, homebuilt aircraft s= tructures.
  So Hamid --I do not believe you can make a statement = regarding "No one has done anything that has led to the airframe failing du= e to modifications." without taking into account accidents that have not be= en adequately examined by properly qualified investigators. For those that = have the potential failure at some lower point of stress/Flutter onset than= expected. This is one of the reasons why Harry's accident is so troubling. Investigators cannot use a canned explanation. <= br>
I do agree wholeheartedly with Hamid's statement that real engineeri= ng analysis is required. Most would agree (depends upon which dog you have = in the fight??)" , but point is, who's going to do it?
 = ;
Charlie K.
See me on the web at
 

From: Hamid Wasti <hwasti@lm50.com>=
To: lml@lancaironline= .net
Sent: Wednesday,= May 9, 2012 1:38 PM
Subject: [LML] Re:= Necessity of A/C in IV-P?

=0ATed Noel wrote:
>= ; 3. Flight testing with a competent test pilot.
>
> I think #= 3 is best since it deals with the variabilities of the installation and cre= ates a hard VNE number.
Does it? How much margin do you have? Testing is= intended to validate engineering analysis, not to substitute it.

&g= t; Also, there are a lot of A/C installations flying. This implies a degree= of safety.
Does it? How does your installation compare to the flying in= stallations? How much safety margin do they have and how much will you have= ? How far have they pushed their airframe (intentionally and unintentionall= y) and how far will you push yours?

All that the flying installation= s indicate is that no one has done anything in their aircraft that has led = to the airframe failing due to the modifications. Maybe there is enough mar= gin that it has not compromised safety at all. Maybe it has cut deeply into= the safety margin and there have been a lot of very close calls that no one has known about.  Without a real engi= neering analysis taking the big picture in mind, no one really knows.
Regards,

Hamid

--
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