Message-ID: <37D7EA10.2416295B@swefco.com>
Date: Thu, 09 Sep 1999 10:10:42 -0700
From: Hal Woodruff <woodruff@swefco.com>
To: lancair.list@olsusa.com
Subject: LNC2 Dump valve
References: <19990909045644.AAA18832@truman.olsusa.com>
Mime-Version: 1.0

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An incident occurred last weekend at the Lancair flyin that all LNC2
drivers should be aware of.  During the race, one of the participants
had his main gear suck open and extend down to the lock position.  Its
not clear whether just one or both mains extended but at least one of
the green down lights came on.  This occurred at or above 200 knots!  It
was a sudden extension and as soon as the main snapped down, the gear
motor ran and retracted the gear.  The gear motor continued to cycle repeatably.

Later, after landing successfully the airplane was put on jacks and the
gear was cycled.  It became obvious from the sound of moving fluid that
the dump valve had failed.  This is the same valve has caused others to
have intermittant gear motor operation.

Two observations come from this:

1. The dump valve should be replaced with one rated for the job soon if
not immediately;

2. The gear and gear doors were capable of handling a 200+ knot
extension.  There were cracks in the inboard gear doors around the
retract fitting but these were minor and can be easily fixed.  Pretty
amazing that the doors didn't rip off.

Lancair has a replacement valve for a nominal cost (I think its about
$15.00) that's supposedly rated for 2000 psi.  The original valve is not
up to the requirements of the job and rated for something considerably
less.  The new valve is about 1/4" longer and slightly heavier than the
original.  The pipe thread is the same as the original so existing
fittings will work.  I replaced mine last night in a couple of hours
including a retract/leak test.

Hal Woodruff
N360HW - the one with the red tail
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