X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 03 Mar 2006 15:07:04 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d21.mx.aol.com ([205.188.144.207] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 1021314 for lml@lancaironline.net; Fri, 03 Mar 2006 01:08:35 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.207; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d21.mx.aol.com (mail_out_v38_r7.3.) id q.1fa.1b0c05f9 (48600) for ; Fri, 3 Mar 2006 01:07:43 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <1fa.1b0c05f9.3139372f@aol.com> X-Original-Date: Fri, 3 Mar 2006 01:07:43 EST Subject: Re: [LML] Re: Jacking-LNC2 X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1141366063" X-Mailer: 9.0 Security Edition for Windows sub 5300 X-Spam-Flag: NO -------------------------------1141366063 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/2/2006 11:21:44 P.M. Central Standard Time, marv@lancaironline.net writes: Scott I think you're last description is the most accurate of what they do in the shop, therefore middle of the outer section and quite forward under the spar. The place a 10 gallon drum on the tail plae for counterbalance. Is there any likelihood of resultant damand and if so would this be obvious on inspection? <<<<<< If the pressure is outside the split it would have to be forward of the main spar to be under the wing spar - this is not a very good balance point even if the wings are holding up the whole plane in flight. >>>>>>> Outboard of the split the spar cap is about 3" wide and of course, the further out one goes both the caps and the web become thinner and lighter since they have to carry less weight in flight. Since the material directly below the spar cap is solid glass, except for the micro used to fill out the seam, I suppose one could support the wing there, But fore and aft of the spar cap (located perhaps by tapping on skin and listening for a solid/hollow sound) is just an occasional rib or skins separated by foam. The areas away from the spar cap can be damaged. Oops. Unfortunately, if the wing tanks are full, that area may also sound solid when tapping. Angier mentioned an alternative method (approved by Lance) of using the tie-down opening as a jack point. This may be ok because the metal of the tie down plate is floxed and glassed to the aft side of the spar web between two ribs that define the aileron bell crank cavity. Plus, the metal tube comes to the bottom skin, thus making it and the spar cap suitable as a lift pad with a locating point. The problem I see with points along the outboard wing spar is that in flight the load is distributed along the entire length of the wing where liftring any specific point is concentrating the weight at that point. I take it that they (your shop) are both holding up the tail and securing it to a hold down weight. Finally, if the damage is only paint/micro deep directly under the spar cap, it may only be cosmetic. Damage aft of the spar, outboard of the split and inboard of the aileron bell crank compartment may affect the integrity of the fuel tanks while forward may affect the integrity of the D-section and thus, the wing. Someone familiar with the Lancair construction may be able to determine if skin damage is structural by inspecting it. Frankly, I would stick with future jacking at the defined jack points for safety's sake - even if you have to construct the jacks. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) PS Have a chat with Dom Crain at _domcrain@pacific.net.au_ (mailto:domcrain@pacific.net.au) -------------------------------1141366063 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 3/2/2006 11:21:44 P.M. Central Standard Time,=20 marv@lancaironline.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Scott I=20 think you're last description is the most accurate of what they do=20
in
the shop, therefore middle of the outer section and quite forwar= d=20 under the
spar. The place a 10 gallon drum on the tail plae for=20 counterbalance. Is there
any likelihood of resultant damand and if so w= ould=20 this be obvious on
inspection?
<<<<<<
If the pressure is outside the split it would have to be forward of the= =20 main spar to be under the wing spar - this is not a very good balance point=20= even=20 if the wings are holding up the whole plane in flight.
>>>>>>>
 
Outboard of the split the spar cap is about 3" wide and of course,= the=20 further out one goes both the caps and the web become thinner and lighter si= nce=20 they have to carry less weight in flight.  Since the material directly=20 below the spar cap is solid glass, except for the micro used to fill out the= =20 seam, I suppose one could support the wing there,  But fore and aft of=20= the=20 spar cap (located perhaps by tapping on skin and listening for a solid/hollo= w=20 sound) is just an occasional rib or skins separated by foam.  The areas= =20 away from the spar cap can be damaged. Oops.  Unfortunately,=20= if=20 the wing tanks are full, that area may also sound solid when=20 tapping. 
 
Angier mentioned an alternative method (approved by Lance) of usin= g=20 the tie-down opening as a jack point.  This may be ok because the metal= of=20 the tie down plate is floxed and glassed to the aft side of the spar web bet= ween=20 two ribs that define the aileron bell crank cavity.  Plus, th= e=20 metal tube comes to the bottom skin, thus making it and the spar=20 cap suitable as a lift pad with a locating point.
 
The problem I see with points along the outboard wing spar is that= in=20 flight the load is distributed along the entire length of the wing=20 where liftring any specific point is concentrating the weight=20 at that point.
 
I take it that they (your shop) are both holding up the tail and=20 securing it to a hold down weight.
 
Finally, if the damage is only paint/micro deep directly under the spar= =20 cap, it may only be cosmetic.  Damage aft of the spar, outboard of= the=20 split and inboard of the aileron bell crank compartment may affect the integ= rity=20 of the fuel tanks while forward may affect the integrity of the D-secti= on=20 and thus, the wing.  Someone familiar with the Lancair construction may= be=20 able to determine if skin damage is structural by inspecting it.
 
Frankly, I would stick with future jacking at the defined jack points f= or=20 safety's sake - even if you have to construct the jacks.
 
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)
 
PS Have a=20 chat with Dom Crain at domcrain@pacific.net.au

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