X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 26 Jan 2011 20:23:05 -0500 Message-ID: X-Original-Return-Path: Received: from [69.84.129.242] (HELO asp.reflexion.net) by logan.com (CommuniGate Pro SMTP 5.4c2a) with ESMTPS id 4826421 for lml@lancaironline.net; Tue, 25 Jan 2011 17:51:12 -0500 Received-SPF: none receiver=logan.com; client-ip=69.84.129.242; envelope-from=cberland@systems3.net Received: (qmail 32235 invoked from network); 25 Jan 2011 22:50:37 -0000 Received: from unknown (HELO mail-cs-02.app.dcb.reflexion.net) (10.84.19.2) by 0 (rfx-qmail) with SMTP; 25 Jan 2011 22:50:37 -0000 Received: by mail-cs-02.app.dcb.reflexion.net (Reflexion email security v6.20.4) with SMTP; Tue, 25 Jan 2011 17:50:37 -0500 (EST) Received: (qmail 14363 invoked from network); 25 Jan 2011 22:50:37 -0000 Received: from unknown (HELO remote.systems3.net) (98.172.79.178) by 0 (rfx-qmail) with (AES128-SHA encrypted) SMTP; 25 Jan 2011 22:50:37 -0000 Received: from S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b]) by S3SBS08SERVER.Systems3.local ([fe80::6077:364b:fa39:c71b%10]) with mapi; Tue, 25 Jan 2011 15:50:35 -0700 From: Craig Berland. X-Original-To: Lancair Mailing List X-Original-Date: Tue, 25 Jan 2011 15:50:37 -0700 Subject: [LML] Engine mount cracks Thread-Topic: [LML] Engine mount cracks Thread-Index: Acu82ZF8DhTs8Hl7QK26jsJf33eG0gAAu9eg X-Original-Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_D7A6B5700A0803448C27264F1F5387364945932309S3SBS08SERVER_" MIME-Version: 1.0 --_000_D7A6B5700A0803448C27264F1F5387364945932309S3SBS08SERVER_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Michael, I make a living making aerospace parts....Boeing is my largest customer....= so I think my advice is sound. 4000 series steels like 4130, 4330 and 4340 are susceptible to cracking aft= er weld if they are not preheated and post heated during the weld process. = I do not know what material your engine mount is made of but the 4000 seri= es steels (chrome moly) are quite popular for this kind of application. I = would be very leery of welding or re-welding steel tube and not knowing wha= t kind of steel it is. Additionally, the quality of weld on your engine mo= unt is not very good. I would suggest replacing the mount unless you can c= onfirm what material the mount was made from. If you choose to repair the = mount, Lancair should have specified the material and the fab house should = have material certs from the original build. Whether or not that informati= on is still available....I don't know. Finding a good welder at an airport= may be challenging. Another thought...losing the nose gear due to mount f= ailure would be very expensive. Craig Berland IV-P N7VG <> --_000_D7A6B5700A0803448C27264F1F5387364945932309S3SBS08SERVER_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Michael,

 

I make a living making aerospace parts….Boein= g is my largest customer….so I think my advice is sound.

4000 series ste= els like 4130, 4330 and 4340 are susceptible to cracking after weld if they= are not preheated and post heated during the weld process.  I do not = know what material your engine mount is made of but the 4000 series steels = (chrome moly) are quite popular for this kind of application.  I would= be very leery of welding or re-welding steel tube and not knowing what kin= d of steel it is.  Additionally, the quality of weld on your engine mo= unt is not very good.  I would suggest replacing the mount unless you = can confirm what material the mount was made from.  If you choose to r= epair the mount, Lancair should have specified the material and the fab hou= se should have material certs from the original build.  Whether or not= that information is still available….I don’t know.  Findi= ng a good welder at an airport may be challenging.  Another thought= 230;losing the nose gear due to mount failure would be very expensive.=

&n= bsp;

Cra= ig Berland

IV-P N7VG

 

 

<<The two attached images show a crack in the engine mount on m= y Lancair IV-P. #4637 shows context and #4641 details. The opposite side cr= acked in a similar fashion two years ago. (I have not had nose wheel shimmy= .)


I would like advice on appropriate repair. My m= echanic is suggesting some form of gusset which could improve the overall s= trength and prevent a future occurrence.

I wonder if this might not = be asking for trouble. Without doing some serious engineering you could cre= ate point loads that might be worse.

 =

Rather than remove the mount I would like to fly the plane to a = highly skilled welder to make this repair. Any references for someone in th= e Northeast.

Other comments anyone?

Michael Newman>>

 

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