X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 10 Jan 2009 18:23:17 -0500 Message-ID: X-Original-Return-Path: Received: from smtp0.av-mx.com ([137.118.16.56] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3418012 for lml@lancaironline.net; Fri, 09 Jan 2009 07:31:33 -0500 Received-SPF: pass receiver=logan.com; client-ip=137.118.16.56; envelope-from=tkhall@highland.net Received: from [10.134.229.158] (unknown [166.133.195.42]) (Authenticated sender: tkhall@highland.net) by smtp0.av-mx.com (Postfix) with ESMTP id B078D1BF803 for ; Fri, 9 Jan 2009 07:30:56 -0500 (EST) X-Original-Message-Id: <2A26E916-0FDB-4B08-B1E6-5F0B581CA869@highland.net> From: Tom Hall X-Original-To: Lancair Mailing List In-Reply-To: Content-Type: multipart/alternative; boundary=Apple-Mail-2--206018848 X-Mailer: iPhone Mail (5G77) Mime-Version: 1.0 (iPhone Mail 5G77) Subject: IV-PT Crash X-Original-Date: Fri, 9 Jan 2009 05:30:49 -0700 References: --Apple-Mail-2--206018848 Content-Type: text/plain; charset=us-ascii; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Turbine IV lost power on go around at Allen Co KS on Wed. Aircraft ended up off of NW end of RW 10 and burned. Pilot survived with back injury. Sent from my iPhone On Jan 8, 2009, at 5:07 PM, Joe Trepicone wrote: > FYI. I believe Bill Maddox just replaced a damaged windshield on a > IVPT a couple months ago. I know it was more difficult with the top > on but it seemed to go well and quickly. I'm sure he'd be happly to > help. I have his email and phone number if you need it. Joe > > > On Jan 6, 2009, at 9:22 PM, vtailjeff@aol.com wrote: > >> I concur that the method of repair is problematic. Flying with a >> cracked windshield especially in a pressurized airplane is not >> recommended. If the window were to fail (worst case) is it would be >> catastrophic for the pilot and passengers. I know this is not what >> one would like to hear but the only solution I see here is to >> remove and replace the windshield. >> >> Best Regards, >> >> Jeff >> >> >> -----Original Message----- >> From: REHBINC >> To: lml@lancaironline.net >> Sent: Mon, 5 Jan 2009 11:32 am >> Subject: [LML] Re: L-IVP Cracked Windshield >> >> Bill, >> >> My guess is that a residual stress was introduced when you replaced >> the brace after the gear failure. This has been acting on the >> windshield ever since, and along with operational loads, has given >> you this new crack. >> >> Drilling the crack tip will reduce the stress concentration from >> infinity to some calculable value. This will make things a whole >> lot better for awhile, however, it won't necessarily prevent the >> crack continuing to propagate. Gluing carbon fiber across the crack >> MAY restore the structural integrity, but it won't remove the >> residual strain at the crack tip. Unfortunately, the initial crack >> probably transformed a rather broadly curved distortion in the >> windshield opening into a much more angular one. Adding the carbon >> fiber reinforcement will reinforce the deformation rather than >> remove it. Until the deformation is removed or the crack propagates >> far enough to reduce the strain to an acceptable level, the crack >> will keep growing. >> >> It is possible that the crack has already extended far enough to >> reduce the strain and that drilling the crack tip will arrest the >> problem, but I doubt it. It will probably continue to propagate >> some additional distance before the strain is adequately reduced >> and drilling the crack will be effective. >> >> I can envision braces being attached to the windshield opening to >> restore it to its original shape, and thereby removing the residual >> stress in the plexiglass. You might also be able to reinforce the >> windshield in front of the crack tip to prevent the distortion from >> traveling with the crack, but this will probably impair vision. All >> of this seems a lot more complicated and involved than just cutting >> out the windshield and gluing in a replacement. >> >> Sorry this isn't what you wanted to hear. >> >> Rob >> >> >> Get a free MP3 every day with the Spinner.com Toolbar. Get it Now. --Apple-Mail-2--206018848 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Turbine IV lost power on go around = at Allen Co KS on Wed. Aircraft ended up off of NW end of RW 10 and = burned. Pilot survived with back injury. 

Sent from my = iPhone

On Jan 8, 2009, at 5:07 PM, Joe Trepicone <aviation@trepicone.com> = wrote:

FYI. = I believe Bill Maddox just replaced a damaged windshield on a IVPT a = couple months ago. I know it was more difficult with the top on but it = seemed to go well and quickly. I'm sure he'd be happly to help.  I = have his email and phone number if you need it. = Joe


On Jan 6, 2009, at 9:22 PM, vtailjeff@aol.com = wrote:

I concur = that the method of repair is problematic. Flying with a cracked = windshield especially in a pressurized airplane is not recommended. If = the window were to fail (worst case) is it would be catastrophic for the = pilot and passengers. I know this is not what one would like to = hear but the only solution I see here is to remove and replace the = windshield.

Best Regards,

Jeff


-----Original Message-----
From: REHBINC <rehbinc@aol.com>
To: lml@lancaironline.net
Sent: Mon, 5 Jan 2009 11:32 am
Subject: [LML] Re: L-IVP Cracked Windshield

Bill,
 
My guess is that a residual stress = was introduced when you replaced the brace after the gear failure. This = has been acting on the windshield ever since, and along with operational = loads, has given you this new crack.
 
Drilling the crack tip will reduce = the stress concentration from infinity to some calculable value. This = will make things a whole lot better for awhile, however, it won't = necessarily prevent the crack continuing to propagate. Gluing carbon = fiber across the crack MAY restore the structural integrity, but it = won't remove the residual strain at the crack tip. Unfortunately, = the initial crack probably transformed a rather broadly curved = distortion in the windshield opening into a much more angular one. = Adding the carbon fiber reinforcement will reinforce the deformation = rather than remove it. Until the deformation is removed or the crack = propagates far enough to reduce the strain to an acceptable level, the = crack will keep growing.
 
It is possible that the crack has = already extended far enough to reduce the strain and that drilling the = crack tip will arrest the problem, but I doubt it. It will probably = continue to propagate some additional distance before the strain is = adequately reduced and drilling the crack will be = effective.
 
I can envision braces being = attached to the windshield opening to restore it to its original shape, = and thereby removing the residual stress in the plexiglass. You might = also be able to reinforce the windshield in front of the crack tip to = prevent the distortion from traveling with the crack, but this will = probably impair vision. All of this seems a lot more complicated = and involved than just cutting out the windshield and gluing in a = replacement.
 
Sorry this isn't what you wanted to = hear.
 
Rob 
 

Get a free MP3 every day with the = Spinner.com Toolbar. Get it Now.
= --Apple-Mail-2--206018848--