X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 23 Apr 2008 13:11:59 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m21.mx.aol.com ([64.12.137.2] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2868716 for lml@lancaironline.net; Wed, 23 Apr 2008 11:48:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.2; envelope-from=RWolf99@aol.com Received: from RWolf99@aol.com by imo-m21.mx.aol.com (mail_out_v38_r9.3.) id q.c25.340e95f6 (34894) for ; Wed, 23 Apr 2008 11:48:07 -0400 (EDT) Received: from mblk-d46 (mblk-d46.mblk.aol.com [205.188.212.230]) by cia-da01.mx.aol.com (v121.4) with ESMTP id MAILCIADA013-884e480f5a368e; Wed, 23 Apr 2008 11:48:06 -0400 X-Original-To: lml@lancaironline.net Subject: Window Strength X-Original-Date: Wed, 23 Apr 2008 11:48:06 -0400 X-MB-Message-Source: WebUI X-AOL-IP: 72.19.171.41 X-MB-Message-Type: User MIME-Version: 1.0 From: rwolf99@aol.com Content-Type: multipart/alternative; boundary="--------MB_8CA73708E5624BC_C2C_3231_mblk-d46.sysops.aol.com" X-Mailer: AOL Webmail 36240-STANDARD Received: from 72.19.171.41 by mblk-d46.sysops.aol.com (205.188.212.230) with HTTP (WebMailUI); Wed, 23 Apr 2008 11:48:06 -0400 X-Original-Message-Id: <8CA73708E51600E-C2C-18EE@mblk-d46.sysops.aol.com> X-Spam-Flag: NO ----------MB_8CA73708E5624BC_C2C_3231_mblk-d46.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" <> No sane structural engineer would take credit for the strength of the plexiglass in determining the strength of the fuselage.? Sure, it's a little stronger with the window bonded in, but that small amount of extra strength is not required.? The fuselage is strong enough even with the big hole in it. <> A good rule of thumb is that if you can see the inside of the airplane through the window from the front, so could the air if the window pane were missing.? Since the Legacy side windows are not visible from directly ahead (they are behind the widest part of the airplane) it would be unlikely for the open window to scoop air if it popped open. I see no negative safety implications for the openable Legacy rear window. BTW, in the general discussion of Part 23 and experimental airplanes having different safety standards, Part 23 requires an "alternate means of egress".? On a spam can, there is usually a door on each side.? The Lancair 360 would not be certifiable with its single means of egress (the openable canopy).? It's possible that you could convince the FAA that a canopy breaker tool is an "alternate means", but it would be a tough argument to win. - Rob Wolf ----------MB_8CA73708E5624BC_C2C_3231_mblk-d46.sysops.aol.com Content-Transfer-Encoding: 7bit Content-Type: text/html; charset="us-ascii" <<The question some people see in this is what does it do to the plane structurally not having the window as part of the structure? Maybe it is not included as part of the structure?>>

No sane structural engineer would take credit for the strength of the plexiglass in determining the strength of the fuselage.  Sure, it's a little stronger with the window bonded in, but that small amount of extra strength is not required.  The fuselage is strong enough even with the big hole in it.

<<what are the effects of the wind on the structure if the window opens in high speed flight?>>

A good rule of thumb is that if you can see the inside of the airplane through the window from the front, so could the air if the window pane were missing.  Since the Legacy side windows are not visible from directly ahead (they are behind the widest part of the airplane) it would be unlikely for the open window to scoop air if it popped open.

I see no negative safety implications for the openable Legacy rear window.

BTW, in the general discussion of Part 23 and experimental airplanes having different safety standards, Part 23 requires an "alternate means of egress".  On a spam can, there is usually a door on each side.  The Lancair 360 would not be certifiable with its single means of egress (the openable canopy).  It's possible that you could convince the FAA that a canopy breaker tool is an "alternate means", but it would be a tough argument to win.

- Rob Wolf
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