X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 01 Apr 2010 10:01:00 -0400 Message-ID: X-Original-Return-Path: Received: from [216.40.44.34] (HELO smtprelay.hostedemail.com) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4191828 for lml@lancaironline.net; Thu, 01 Apr 2010 09:55:58 -0400 Received-SPF: none receiver=logan.com; client-ip=216.40.44.34; envelope-from=micah@froese.com Received: from filter.hostedemail.com (ff-bigip1 [10.5.19.254]) by smtprelay02.hostedemail.com (Postfix) with SMTP id CFDD012715CD for ; Thu, 1 Apr 2010 13:55:20 +0000 (UTC) X-Panda: scanned! X-Session-Marker: 6D696361684066726F6573652E636F6D X-Filterd-Recvd-Size: 3744 Received: from [192.168.0.10] (h219.96.21.98.dynamic.ip.windstream.net [98.21.96.219]) (Authenticated sender: micah@froese.com) by omf01.hostedemail.com (Postfix) with ESMTP for ; Thu, 1 Apr 2010 13:55:19 +0000 (UTC) X-Original-Message-ID: <4BB4A5C4.1020003@froese.com> X-Original-Date: Thu, 01 Apr 2010 09:55:16 -0400 From: Micah Froese User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: [LML] Legacy maintenance idea References: In-Reply-To: Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Tom,

Regarding attachment of the stub wing skin, I would strongly recommend Hysol for quite a few reasons. At the speeds a Legacy travels, I find it pretty hard to envision a mechanical method of fastening that would preclude any and all possibility of flutter/vibration somewhere between the leading edge and trailing edge. Then there's the problem of the leading edge, which is quite critical on our airplane. Factory data shows that even when something as as small as their landing light is installed in the leading edge, there is a significant speed penalty. Having a gap, regardless of how perfect it's made, opens you up to a big unknown aerodynamic question mark. Then there's the issue of reliability, there's got to be a way to ensure redundancy, verifiability, etc. Losing a stub skin in flight would be catastrophic. (it's happened once before on a Legacy)

Thought about from another angle, I'm not sure there would be any real advantage being able to open the stub wing. There isn't that much under there; normal gear, strut, and tire service is easily accomplished from below. Can't really think of anything that I've had to do in the last 400 hours of flying that makes me wish the skin was removable. Anything on a big scale, say rebuilding the strut, requires it's complete removal, which can be done from below.

It's definitely an interesting idea, but from my limited perspective I see few, if any real advantages, and only and increase in weight, complexity, maintenance, etc. Remember, as with anything installed on an airplane, it can fail, it will increase the hours building and maintaining, always winds up adding weight, etc. I have become a firm believer in keeping everything as simple as possible.

Micah Froese
Lancair Legacy
N171MF
400 hours

Posted:  April 1,2010

While working on my Legacy kit it occurred to me that once it's flying inspection

and maintenance of the main gear would be so much easier if the stub wing skin

could be removed.  I attached a hinge to the leading edge so that the skin could be
opened as shown in the picture.  Now I'm trying to decide what sort of fasteners

I should use on the trailing edge.  Any suggestions?

Tom Gourley