X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 16 Aug 2010 12:56:27 -0400 Message-ID: X-Original-Return-Path: Received: from TX2EHSOBE004.bigfish.com ([65.55.88.12] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTPS id 4432720 for lml@lancaironline.net; Mon, 16 Aug 2010 12:44:05 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.55.88.12; envelope-from=rpastusek@htii.com Received: from mail171-tx2-R.bigfish.com (10.9.14.251) by TX2EHSOBE004.bigfish.com (10.9.40.24) with Microsoft SMTP Server id 8.1.340.0; Mon, 16 Aug 2010 16:43:28 +0000 Received: from mail171-tx2 (localhost.localdomain [127.0.0.1]) by mail171-tx2-R.bigfish.com (Postfix) with ESMTP id 27D96F01E5 for ; Mon, 16 Aug 2010 16:43:28 +0000 (UTC) X-SpamScore: -4 X-BigFish: VPS-4(zzace9izz1202hzz186M8275bh8275dhz2fh2a8h63h) X-Spam-TCS-SCL: 2:0 Received: from mail171-tx2 (localhost.localdomain [127.0.0.1]) by mail171-tx2 (MessageSwitch) id 1281977007132000_19740; Mon, 16 Aug 2010 16:43:27 +0000 (UTC) Received: from TX2EHSMHS010.bigfish.com (unknown [10.9.14.242]) by mail171-tx2.bigfish.com (Postfix) with ESMTP id 15C7C748052 for ; Mon, 16 Aug 2010 16:43:27 +0000 (UTC) Received: from va3diahub020.RED001.local (65.55.171.153) by TX2EHSMHS010.bigfish.com (10.9.99.110) with Microsoft SMTP Server (TLS) id 14.0.482.44; Mon, 16 Aug 2010 16:43:26 +0000 Received: from VA3DIAXVS171.RED001.local ([172.18.2.196]) by va3diahub020.RED001.local ([10.32.21.20]) with mapi; Mon, 16 Aug 2010 09:43:26 -0700 From: Robert R Pastusek X-Original-To: Lancair Mailing List X-Original-Date: Mon, 16 Aug 2010 09:43:26 -0700 Subject: IV-P Door Window Replacement Thread-Topic: IV-P Door Window Replacement Thread-Index: Acs8jYp1HMOGcl9wTNiKJA3nCs359wAwhXHg X-Original-Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-cr-hashedpuzzle: 8I8= AEaZ BRKw BtK3 C3Y4 GLKP GjLh HF+z HICZ Hn+b Hop6 H3bV J5JB KzG/ K3HR MCHS;1;bABtAGwAQABsAGEAbgBjAGEAaQByAG8AbgBsAGkAbgBlAC4AbgBlAHQA;Sosha1_v1;7;{CED5B02F-A386-4CE9-9615-CB4E6AC3F4E1};cgBwAGEAcwB0AHUAcwBlAGsAQABoAHQAaQBpAC4AYwBvAG0A;Mon, 16 Aug 2010 14:52:24 GMT;SQBWAC0AUAAgAEQAbwBvAHIAIABXAGkAbgBkAG8AdwAgAFIAZQBwAGwAYQBjAGUAbQBlAG4AdAA= x-cr-puzzleid: {CED5B02F-A386-4CE9-9615-CB4E6AC3F4E1} acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E374BE0180357344BBD396A27A0527F6015A8094D2VA3DIAXVS171R_" MIME-Version: 1.0 X-Reverse-DNS: smtp801.microsoftonline.com X-Original-Return-Path: rpastusek@htii.com --_000_E374BE0180357344BBD396A27A0527F6015A8094D2VA3DIAXVS171R_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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_E374BE0180357344BBD396A27A0527F6015A8094D2VA3DIAXVS171R_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

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 complete report on this, and have made careful notes and pictures for this.= It appears the report will need to be delayed a bit, so I thought I should pro= vide 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=A0 a 2 inch “crackle” in the = 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. 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 w= indow frame. Neither end of the crack extended to the edge of the Plexiglas, and = did not intersect either of the door latch mounting holes that had been oversiz= ed, 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=A0 away and the mounti= ng 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 to swin= g open hard in the wind against the air strut, and one or both of these almos= t certainly caused the crack—although I did not see it at the time. I h= ave routinely taxied the airplane over rough ramps/etc with the canopy 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!=A0 Detailed report to the LML when I can.

 

Bob

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