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From: Robert R Pastusek <rpastusek@htii.com>
To: Lancair Mailing List <lml@lancaironline.net>
Subject: RE: [LML] Re: Oleo Strut Over-Rotation
Thread-Topic: [LML] Re: Oleo Strut Over-Rotation
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Date: Mon, 5 May 2014 21:54:56 +0000
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John,

I answered your specific question about the shimmy damper function, but sho=
uld have also pointed out that a defective shimmy damper will not cause a l=
ateral veering with a 3-second period that you asked about in another LML p=
ost. The period of oscillation the damper is designed to mitigate is on the=
 order of several oscillations per second. As noted in the article I sent e=
arlier, this can be violent enough to break the motor mount, and it happens=
 so fast once it starts that you likely won't have time to react. It's ther=
efore important that the damper be functional as you start flying.

Reference Bill Harrelson's email back to you on directional control, you ma=
y have more than one issue/problem. Both are potentially serious enough to =
warrant a careful check before trying to fly.

 Bob=20

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Robe=
rt R Pastusek
Sent: Monday, May 05, 2014 5:19 PM
To: Lancair Mailing List
Subject: [LML] Re: Oleo Strut Over-Rotation

John,
I'm sending you an article we published in the LOBO Newsletter about this t=
hree years ago. Notes and changes are courtesy of Chris Zavatson--thanks Ch=
ris!  Short answer is that if your nose wheel will turn more than 60 degree=
s left or right (45 degrees for an original, unmodified strut), the shimmy =
damper in the strut has been damaged and is inop/ineffective. See the attac=
hed article for details.

Bob

-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of John=
 Cooper
Sent: Monday, May 05, 2014 10:27 AM
To: Lancair Mailing List
Subject: [LML] Oleo Strut Over-Rotation

We know that Esco limits the rotation of the oleo strut to +/- 25=BA, but w=
hat happens when that limit is exceeded? How would one know that it had bee=
n exceeded? I noticed yesterday when turning my L-235 around at the end of =
the runway that I could almost do a U-turn; certainly my nose wheel was ang=
led at more than 25=BA during the turn.  I'm wondering if internal oleo-str=
ut damage due to over-rotation could be the source of the problem I'm havin=
g with directional control while fast-taxiing. Anybody?

--
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