X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 23 Jun 2007 07:51:27 -0400 Message-ID: X-Original-Return-Path: Received: from [64.12.136.172] (HELO imo-m13.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2135472 for lml@lancaironline.net; Sat, 23 Jun 2007 07:14:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.136.172; envelope-from=MikeEasley@aol.com Received: from MikeEasley@aol.com by imo-m13.mx.aol.com (mail_out_v38_r9.2.) id q.be8.1a1b6721 (43931) for ; Sat, 23 Jun 2007 07:13:38 -0400 (EDT) From: MikeEasley@aol.com X-Original-Message-ID: X-Original-Date: Sat, 23 Jun 2007 07:13:38 EDT Subject: Re: [LML] Re: [Fwd: nose wheel shimmy] X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1182597218" X-Mailer: 9.0 Security Edition for Windows sub 5365 X-Spam-Flag: NO -------------------------------1182597218 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Tim Ong attempted to modify the struts to use thinner 5606 fluid but it was unsuccessful. I also ran some viscosity tests on Belray 30W and several other fork oils in an effort to find another oil that had better temperature characteristics. I included some premium fork oils that claim to be stable at high temperatures. None of them performed very well. I used a Zahn cup to measure the viscosity. All of the oils lost about half of their viscosity (measured in time) in only 30 degrees F. Belray 30W took 2:00 at 60F, 1:00 at 90F, and :32 at 120F. My shimmy incident happened when I was doing training. I believe my strut was much warmer than usual. I had just completed a half hour of slow flight, then some go-arounds, then the shimmy happened during the rollout on a no flap landing. Combine being a little high, a little fast, a little long, a little more braking than usual, and a rough runway. Wham! Shimmy! I got off the brakes and the shimmy stopped and I rolled out with very light braking into the overrun area. Lancair has also developed some "higher toleranced" parts and a couple modifications to the struts to make them more durable. I sent my strut in for servicing and they did the mods, about $400. I've only got about 25 hours on my airplane since the rebuild. I had no damage to my engine mount but the severe rock 'n roll caused my baffling to hit my cowl and I got a crack that had to be repaired. The jury is still out on how much better they perform with the modifications. I know of two ES struts that have failed within a short time of being serviced, one had shimmy, the other severe leaking. I do the greased plate test before every flight now. Mike Easley Super ES ************************************** See what's free at http://www.aol.com. -------------------------------1182597218 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Tim Ong attempted to modify the struts to use thinner 5606 fluid but it= was=20 unsuccessful.

I also ran some viscosity tests on Belray 30W and several other fork oi= ls=20 in an effort to find another oil that had better temperature=20 characteristics. I included some premium fork oils that claim to be st= able=20 at high temperatures. None of them performed very well. I used a= =20 Zahn cup to measure the viscosity. All of the oils lost about half of=20 their viscosity (measured in time) in only 30 degrees F. Belray 30W to= ok=20 2:00 at 60F, 1:00 at 90F, and :32 at 120F.

My shimmy incident happened when I was doing training. I believe=20= my=20 strut was much warmer than usual. I had just completed a half hour of=20= slow=20 flight, then some go-arounds, then the shimmy happened during the rollout on= a=20 no flap landing. Combine being a little high, a little fast, a little=20 long, a little more braking than usual, and a rough runway. Wham! = ;=20 Shimmy! I got off the brakes and the shimmy stopped and I rolled out w= ith=20 very light braking into the overrun area.

Lancair has also developed some "higher toleranced" parts and a co= uple=20 modifications to the struts to make them more durable. I sent my=20 strut in for servicing and they did the mods, about $400. I've only go= t=20 about 25 hours on my airplane since the rebuild. I had no damage to my= =20 engine mount but the severe rock 'n roll caused my baffling to hit my cowl a= nd I=20 got a crack that had to be repaired.

The jury is still out on how much better they perform with the=20 modifications. I know of two ES struts that have failed within a short= =20 time of being serviced, one had shimmy, the other severe leaking.

I do the greased plate test before every flight now.

Mike Easley

Super ES

See what's f= ree at AOL.com= .

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