Mailing List lml@lancaironline.net Message #40264
From: <marv@lancair.net>
Subject: Re: [LML] Re: Fuel tank camera for inspection of Lancair fuel tanks
Date: Mon, 26 Feb 2007 11:52:13 -0500
To: <lml@lancaironline.net>
Posted for "Steitle, Mark R" :

Bryan,

I was having afterthoughts on how I addressed the possibility of fuel
tank static on my ES. Up until now I thought I had been totally anal
about this, but I'm feeling much better about it now. First, I started
by electrically connecting the fuel tank vent lines to the filler rings.
Then I put a SS screen around the filler rings so the fuel would have to
pass through the screen to get into the tanks. Then I ran ground wires
out to the wing tips and connected them to the vent lines. These are
now grounded to the a/c ground system, which includes the engine. So,
when the line boy connects the ground to the exhaust, it will ground all
the way from the fuel ring to ground. Maybe I should ground the landing
gear and tie-downs too?

Mark S.

"""
We all know what happened to Hoyt Flemming's airplane during a
repainting project. The fuel tank was emptied and after sanding, and
blowing the dust off with air there was flash and fire that ruined the
airplane.

Shortly thereafter I painted my airplane. I can honestly say that I was
aware of the problem and paid particular attention to static buildup
when working with the wings. The wings had been removed from the
fuselage.

I was amazed at how little effort it took to build a static charge.
When polishing or buffing I could feel the static when the hair on my
arms would stand up. So I made sure that the floor was wet and that I
didn't go very long without doing something to eliminate the static.
Especially around the fuel filler ports. I used the plastic inexpensive
fuel caps and made sure the ports were sealed off with tape over the
fuel caps. I also wiped the wings often with damp cloths. I made it
through the painting process without any problems but I was nervous.
Another option would be to paint the wings before any fuel is introduced
to the system.

During refueling I would think that if you devise a way to positively
ground the fuel nozzle to the metal fuel filler port ring that this
would be a good thing. I make sure the fuel nozzle is always touching
the ring.

In a carbon fiber airplane I would think that the nose gear strut or
exhaust pipe would be a good point to attach the static cable in
addition to the nozzle metal ring contact. In an ES there really is not
a good place to ground the static cable. But FBO's have to attach it
somewhere so I use the tow bar plate.

Perhaps during building and closing the wing and sealing the fuel bays
it may be a good idea to add a ground wire that attach to the metal ring
and then to a common ground that ultimately connects to the engine/nose
strut/tow bar plate etc. But after the wing is closed this is not going
to happen.

There has been some conversation on the Lanciar ES Yahoo group about
using metal based primer and gaining conductivity for both ground
handling and in flight static wick discharge. I don't know where this
ever ended or what products were available.

Bryan J. Burr
N132BB
""""
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