Date: Sun, 11 Mar 2001 21:19:20 EST
From: AVIDWIZ@aol.com
Subject: Landing Gear Design on IV-P
To: <lancair.list@olsusa.com>
Message-ID: <37.11dcaa34.27dd8c26@aol.com>
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

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Dear List Members,

About 2 weeks ago I sent the following email to Lance regarding what appears to be a design flaw in the landing gear on the IVP which results in the gear doors hanging up the gear.  This is related to the size of the runners on the gear doors.

Many of you have helped me figure this out and I had hoped that Lance would reply to either me or to this list and update everyones understanding of the issue.

Sadly he has not even though Don Goetz at the factory told me on the phone that they are going to address this size issue in future kits....never mind all the kits being built.

I hope this information is of some use.

The email I sent which speaks for itself is as follows:

Dear Lance,

I have found what I believe is a design flaw in the landing gear on the IV-P.
While your factory pilots do not seem to experience similar problems, this
aircraft built by John Kerner does.

Specifically, the 1/8" white teflon runner does not have enough rigidity
during extension & retraction.   The gear and air load pressure during
extension causes the 1/8" material to deform and the gear subsequently hangs
up due to this deformity during retraction.

I have spoken to several owners all of whom have had the same problem and if
you have been following the Lancair builders email list, you are aware of
their comments.

I have shot ground to air photos which document the problem and which have
been sent to you.

Charlie Kohler specifically said he had several problems on his plane as well
as on others he has test flown and was intending to change his runner design
as well.

Your factory suggests additional carbon lay ups to make the gear door more
rigid but this is a "band-aide on a belly wound" as it were, since the real
problem lies in the runners ability to handle the extreme pressures placed
upon it and not upon the door supporting the runner.

In case you are wondering about gear speeds, the test I carried out involved
extending the gear at or below 140KIAS and retraction at or before 100 KIAS,
both well within specifications.

I have secured the advice of several experts and have been told that the best
answer is to install a 1/4" replacement for the 1/8" runners supplied with
the kit.

I will be doing that this weekend and offer this information to you in the
hopes that this matter will be addressed by your staff and notification made
to other builders so that they need not go thru the same incidents of
elevated blood pressure and puckerd seats which I have experienced when
seeing the now all too familiar, "GEAR RED" light!

For your evaluation, once they are removed I will send the old runners to you
for you to inspect so you can see what 43 hours of flight time does to the
1/8" material.

Regards,

Dave Riggs
N-424E
Beverly Hills, CA.


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Please send your photos and drawings to marvkaye@olsusa.com.
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