From: Jimnordin@aol.com
Message-ID: <c45eb59b.36654ad5@aol.com>
Date: Wed, 2 Dec 1998 09:12:37 EST
To: lancair.list@olsusa.com
Subject: ES tire blowout and wear characteristics.
Mime-Version: 1.0

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An ES owner (not a part of this forum) recently experienced a blowout of the
left main after 140 hours ( don't know how many landings that equates to but
he makes mostly cross country flights to date). The McCreary tire was totally
devoid of rubber on the inside (maybe the first 1.75 inches). The outer most
threads were worn completely thru and the inner threads were showing wear.
When we replaced the tires last night I noticed the left main had a lot of
"wobble" in it when moved (with the plane on jacks). You  know, hold the tire
and move it forward, backward, in, out, twist etc to observe how much movement
could be attained. We were searching for reasons for the accelerated wear.

Is this movement (wobble) normal? The right main does not exhibit the same
movement characteristics. There is some slop but not the movement of the left.
The right tire had significant wear to the inside also, but no threads were
showing at changeout. He said most of his turns on the ground were to the left
(back taxi etc) when he had the choice to make. He felt this could have
contributed to the accelerated left tire wear. 

Neither of the tires were significantly worn to the outside. Also, neither
were worn much at all at the center 50% of the tire. Could the absence of wear
of the center be contributed to tire pressure? Too low of pressure?

The toe in and other landing gear setup specifications described in the plans
were observed.

Goodyears have replaced the McCreary tires. A noticeably harder compound was
seen.