Sender: <marv@lancaironline.net>
To: lml@lancaironline.net
Date: Fri, 03 Feb 2006 00:20:55 -0500
Message-ID: <redirect-965890@logan.com>
Received-SPF: none
 receiver=logan.com; client-ip=216.148.227.154; envelope-from=rpastusek@htii.com
From: "Robert R Pastusek" <rpastusek@htii.com>
Subject: RE: [LML] static wicks
MIME-Version: 1.0
Content-Type: text/plain;
	charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Importance: Normal
In-Reply-To: <list-963040@logan.com>

Joe Neustein wrote:
I would be most interested to hear how it is working out with those who
elected not to install static wicks (especially in the carbon fuselage since
I am building an ES-P) or from builders who feel strongly that they are a
necessity.

Joe,
I have flown several high performance aircraft that require static wicks to
be considered airworthy. These were not "grounding items" on the F-111, and
they were very prone to break off the edges of the elevators--probably
vibration--but in any case, they were an often-replaced item. We
occasionally flew with one to several missing (don't recall how many total
the aircraft had, but it could have been up to 10 or so?)

My experience was that with even a small number missing, the aircraft would
build up a static charge during some flight conditions--especially during
low altitude flying out in the dry western US where we normally trained. (I
never identified this as a problem while flying in clouds.)  The static
build up would block all radio transmission/reception, and on rare
occasions, interfere with some of the electronic systems. This was common
enough that the accepted "fix" was to slow down and climb to a higher
altitude. After a few minutes, the systems would reset to normal operation,
and the radios would again work fine. I don't ever recall having this
problem flying around the east coast either (higher relative humidity?),
although we typically could never go as low and as fast as we did on the
western test and training ranges...

So to answer your question about need: I think it depends...For me they have
proven to be more effective than elephant repellent. I don't intend to fly
my Lancair like we flew the -111's, BUT the carbon composite construction is
definitely prone to static build up, so I've installed them. If the aircraft
builds up a static charge and it's not dissipated, it will really screw up
your radio operation--to include IFF, GPS, etc, and will be almost
impossible to troubleshoot/isolate because it will appear to occur randomly,
and not be associated with conditions you'll easily identify/recognize. As
far as I can tell, it doesn't cause any permanent damage to equipment.

Hope this helps?

Bob Pastusek