X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Aug 2010 10:10:31 -0400 Message-ID: X-Original-Return-Path: Received: from [216.32.180.31] (HELO VA3EHSOBE005.bigfish.com) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTPS id 4433857 for lml@lancaironline.net; Tue, 17 Aug 2010 09:30:02 -0400 Received-SPF: pass receiver=logan.com; client-ip=216.32.180.31; envelope-from=rpastusek@htii.com Received: from mail187-va3-R.bigfish.com (10.7.14.238) by VA3EHSOBE005.bigfish.com (10.7.40.25) with Microsoft SMTP Server id 8.1.340.0; Tue, 17 Aug 2010 13:29:26 +0000 Received: from mail187-va3 (localhost.localdomain [127.0.0.1]) by mail187-va3-R.bigfish.com (Postfix) with ESMTP id AF7F8582B6 for ; Tue, 17 Aug 2010 13:29:24 +0000 (UTC) X-SpamScore: -28 X-BigFish: VPS-28(zz98dN1447R9371Pace9izz1202hzz186M8275bh8275dh8275chz2fh2a8h61h) X-Spam-TCS-SCL: 0:0 Received: from mail187-va3 (localhost.localdomain [127.0.0.1]) by mail187-va3 (MessageSwitch) id 1282051750741820_6082; Tue, 17 Aug 2010 13:29:10 +0000 (UTC) Received: from VA3EHSMHS016.bigfish.com (unknown [10.7.14.239]) by mail187-va3.bigfish.com (Postfix) with ESMTP id A6E201C6805D for ; Tue, 17 Aug 2010 13:29:07 +0000 (UTC) Received: from VA3DIAHUB005.RED001.local (65.55.171.153) by VA3EHSMHS016.bigfish.com (10.7.99.26) with Microsoft SMTP Server (TLS) id 14.0.482.44; Tue, 17 Aug 2010 13:29:03 +0000 Received: from VA3DIAXVS171.RED001.local ([172.18.2.196]) by VA3DIAHUB005.RED001.local ([10.32.21.105]) with mapi; Tue, 17 Aug 2010 06:29:03 -0700 From: Robert R Pastusek X-Original-To: Lancair Mailing List X-Original-Date: Tue, 17 Aug 2010 06:28:52 -0700 Subject: RE: [LML] Re: IV-P Door Window Replacement Thread-Topic: [LML] Re: IV-P Door Window Replacement Thread-Index: Acs+A4MuML/xQLArSJeOzSSodtdH5gADHu7Q X-Original-Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E374BE0180357344BBD396A27A0527F6015A80977FVA3DIAXVS171R_" MIME-Version: 1.0 X-Reverse-DNS: smtp801.microsoftonline.com X-Original-Return-Path: rpastusek@htii.com --_000_E374BE0180357344BBD396A27A0527F6015A80977FVA3DIAXVS171R_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I've considered it, but Jon is really humping to keep their business going = right now, so I'm not asking for help from him. His latest, "...Dad made it= all look so easy..." Bob From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Coly= n Case Sent: Tuesday, August 17, 2010 7:57 AM To: lml@lancaironline.net Subject: [LML] Re: IV-P Door Window Replacement Bob, thanks for the report. ouch! Is Jonathan going to make a modified gas strut with a snubber built in? On Aug 16, 2010, at 12:56 PM, Robert R Pastusek wrote: I have completed replacement of the door window in my IV-P and N437RP is at= Brad Simmons' shop for painting. I promised to write a complete report on = this, and have made careful notes and pictures for this. It appears the rep= ort will need to be delayed a bit, so I thought I should provide a summary = of what I believe to be the cause. Hopefully this will help some of you in = avoiding my mistakes. The door window in N437RP, and IV-P, developed a crack parallel to the back= edge of the window at approximately 500 hours and two years in service. Th= e crack was completely covered by the inside and outside door frame carbon = fiber, and only visible as a 2 inch "crackle" in the otherwise dark edge o= f the Plexiglas when viewed at a sharp angle from inside or outside of the = door. I continued to fly the airplane for about 10 hours, but did not press= urize it during this time. I removed the transparency from the door by grinding away the outside carbo= n cloth layers to reveal the outside edges of the Plexiglas. By doing this = carefully, I was able to determine that the crack was approximately 4 inche= s long, parallel to, and about =BC" under the back edge of the carbon windo= w frame. Neither end of the crack extended to the edge of the Plexiglas, an= d did not intersect either of the door latch mounting holes that had been o= versized, filled with Hysol and re-drilled to size. This discovery about the nature of the crack led me to conclude that it was= caused by flexing/twisting of the door frame in that immediate area. While= this could be caused by the latch located in the immediate area, this seem= ed unlikely as the crack was almost an inch away and the mounting through-= holes showed no stress or cracking at all. The other source of bending/twisting stress in that area is the attachment = point of the gas lift strut that holds the door open, and I believe this to= have been the source. On two recent occasions, the door has been allowed t= o swing open hard in the wind against the air strut, and one or both of the= se almost certainly caused the crack-although I did not see it at the time.= I have routinely taxied the airplane over rough ramps/etc with the canopy = open, allowing it to bounce against the restraining strut... a practice I w= on't do again. I doubt this is the cause of all door window failures; in fact, mine might = have been unique, but I plan to take much better care of my door in the fut= ure! Detailed report to the LML when I can. Bob --_000_E374BE0180357344BBD396A27A0527F6015A80977FVA3DIAXVS171R_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I’ve considered it, but Jon is really humping to keep = their business going right now, so I’m not asking for help from him. His la= test, “…Dad made it all look so easy…”


Bob

 

From: Lancair Maili= ng List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case
Sent: Tuesday, August 17, 2010 7:57 AM
To: lml@lancaironline.net
Subject: [LML] Re: IV-P Door Window Replacement

 

Bob,   thanks for the report.  ouch!

 

Is Jonathan going to make a modified gas strut with a snubber built in?

 

On Aug 16, 2010, at 12:56 PM, Robert R Pastusek wrote:=



I have completed replacement of the door window in my IV-P a= nd N437RP is at Brad Simmons’ shop for painting. I promised to write a c= omplete report on this, and have made careful notes and pictures for this. It appea= rs the report will need to be delayed a bit, so I thought I should provide a summary of what I believe to be the cause. Hopefully this will help some of= you in avoiding my mistakes.

 

The door window in N437RP, and IV-P, developed a crack paral= lel to the back edge of the window at approximately 500 hours and two years in service. The crack was completely covered by the inside and outside door fr= ame carbon fiber, and only visible as  a 2 inch “crackle” in t= he otherwise dark edge of the Plexiglas when viewed at a sharp angle from inside or outs= ide of the door. I continued to fly the airplane for about 10 hours, but did no= t pressurize it during this time.

 

I removed the transparency from the door by grinding away th= e outside carbon cloth layers to reveal the outside edges of the Plexiglas. B= y doing this carefully, I was able to determine that the crack was approximat= ely 4 inches long, parallel to, and about =BC” under the back edge of the= carbon window frame. Neither end of the crack extended to the edge of the Plexigla= s, and did not intersect either of the door latch mounting holes that had been oversized, filled with Hysol and re-drilled to size.

 

This discovery about the nature of the crack led me to concl= ude that it was caused by flexing/twisting of the door frame in that immediate area. While this could be caused by the latch located in the immediate area= , this seemed unlikely as the crack was almost an inch  away and the mounting through-holes showed no stress or cracking at all.

 

The other source of bending/twisting stress in that area is = the attachment point of the gas lift strut that holds the door open, and I beli= eve this to have been the source. On two recent occasions, the door has been allowed to swing open hard in the wind against the air strut, and one or bo= th of these almost certainly caused the crack—although I did not see it = at the time. I have routinely taxied the airplane over rough ramps/etc with the ca= nopy open, allowing it to bounce against the restraining strut… a practice= I won’t do again.

 

I doubt this is the cause of all door window failures; in fa= ct, mine might have been unique, but I plan to take much better care of my door= in the future!  Detailed report to the LML when I can.<= /p>

 

Bob

 

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