X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Oct 2006 23:17:07 -0400 Message-ID: X-Original-Return-Path: Received: from web34906.mail.mud.yahoo.com ([209.191.68.185] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with SMTP id 1445137 for lml@lancaironline.net; Fri, 06 Oct 2006 00:13:39 -0400 Received-SPF: none receiver=logan.com; client-ip=209.191.68.185; envelope-from=n103md@yahoo.com Received: (qmail 68505 invoked by uid 60001); 6 Oct 2006 04:13:18 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=lvZKNp9dX19Wqb1ZvUc2phfPGEayuucH6eCzgLv+PvmsKuLQly6i6kv4S6sJEiP5dGzLvowmMnTDIE8r+SADQrvunWhjFSv7OZ9EEgzK8rWD5Z2Ykzr4MqKn+U57+Ca2vMU1r9HewFA8zr1r+LxCGVmQdjnpUT5G+jJpPE1Ifpc= ; X-Original-Message-ID: <20061006041318.68503.qmail@web34906.mail.mud.yahoo.com> Received: from [12.146.139.19] by web34906.mail.mud.yahoo.com via HTTP; Thu, 05 Oct 2006 21:13:18 PDT X-Original-Date: Thu, 5 Oct 2006 21:13:18 -0700 (PDT) From: bob mackey Subject: Re: Shudda gone down when the buzzard went up X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-820523898-1160107998=:67971" Content-Transfer-Encoding: 8bit --0-820523898-1160107998=:67971 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit My previous message (#37982) was somehow truncated. The full text is shown below. ----------------------------------------------------------------- Bill & Sue: Glad you kept the rest of the airplane and your skins intact with a safe return to the runway. That must have been some impact. > Where does one begin a repair like this? Well, you could replace the whole wing, but I think it would be faster and easier to repair. I've done some repairs on gliders that had damage comparable to that shown in your photos. Here's how I fixed some of those holes... I would start by making shallow clean cuts through the outer skin about an inch or two beyond the visible damage. Before peeling, try to evaluate whether the core is intact and still bonded to the inner skins. If it is, then cut through the inner skins just at the edge of the damage area. This leaves you an inch or two of overlap between the old inner skin and the new outer skins. Then buy replacement skins from Lancair if available and cut out the part you need for the repair. Make sure that you have core everywhere. Once you've got a good fit between the old and new parts, bond some tabs to the inside of the inner skin to form a joggle for the inner skin joint. Bond the new part in place with a good structural adhesive, being sure to wet all the exposed core before assembly. Do take some time to make jigs that will hold the new skin in just the right spot. An internal rib or two might be part of the jigging. Once it is all bonded into place, take the disk sander to the outer skin joints and sand a 1"-1.5" wide taper so that the outer skin is paper-thin right at the joint. Fill this shallow trough with 1K carbon weave and a good laminating resin. Squeeze it out fairly dry. Then rough-sand the area with ~100 grit then 220 to level the excess carbon down to the proper contour. At that point, you should have a structurally sound repair that adds less than a pound to the airframe. The rest is body working to make it look good. If you're not happy with the results, you can still reskin the wing or replace it altogether. BTW, did you perceive the control imbalance to get worse or better as you reduced airspeed? Did it get worse or better as the flaps came down? I would guess the spoileron effect diminished somewhat with reduced airspeed, and with flap extension. On the other hand, if you had one airspeed with tolerable control authority, why try any other airspeed and possibly find out that it is worse? -bob --------------------------------- All-new Yahoo! Mail - Fire up a more powerful email and get things done faster. --0-820523898-1160107998=:67971 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit My previous message (#37982) was somehow truncated.
The full text is shown below.
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Bill & Sue:

Glad you kept the rest of the airplane and your skins
intact with a safe return to the runway. That must have been
some impact.

> Where does one begin a repair like this?

Well, you could replace the whole wing, but I think it would be faster
and easier to repair.

I've done some repairs on gliders that had damage comparable to
that shown in your photos. Here's how I fixed some of
those holes...

I would start by making
shallow clean cuts through the outer skin about an inch
or two beyond the visible damage. Before peeling, try to
evaluate whether the core is intact and still bonded to the
inner skins. If it is, then cut through the inner skins
just at the edge of the damage area. This leaves you an
inch or two of overlap between the old inner skin and the
new outer skins.

Then buy replacement skins from Lancair if available and
cut out the part you need for the repair. Make sure that you
have core everywhere. Once you've got a
good fit between the old and new parts, bond some tabs to the
inside of the inner skin to form a joggle for the inner skin
joint.

Bond the new part in place with a good structural adhesive,
being sure to wet all the exposed core before assembly.
Do take some time to make jigs that will hold the new skin
in just the right spot. An internal rib or two might be part of the
jigging.

Once it is all bonded into place, take the disk sander to the
outer skin joints and sand a 1"-1.5" wide taper so that the outer
skin is paper-thin right at the joint. Fill this shallow trough with
1K carbon weave and a good laminating resin. Squeeze it out fairly dry.

Then rough-sand the area with ~100 grit then 220 to level the excess
carbon down to the proper contour.  At that point, you should have a
structurally sound repair that adds less than a pound to the airframe.

The rest is body working to make it look good.

If you're not happy with the results, you can still reskin the wing
or replace it altogether.


BTW, did you perceive the control imbalance to get worse or better
as you reduced airspeed?

Did it get worse or better as the flaps came down?

I would guess the spoileron effect diminished somewhat with reduced
airspeed, and with flap extension. On the other hand, if you had one
airspeed with tolerable control authority, why try any other airspeed
and possibly find out that it is worse?

-bob

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