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asarangan(at)gmail.com Guest
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Posted: Wed Dec 18, 2013 3:53 pm Post subject: Static in fuel system |
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I hate to revive this discussion once again, but I am still trying to
figure out the static discharge mechanisms in the Europa fuel system.
I recall at least two Europas that were consumed by static induced
fuel fire. Was there any final report regarding these incidents, so
that we can learn from these?
Europa's fuel tank and the cobra inlet are nonconductive plastic. Even
the filler neck is non conductive (at first I thought this was
aluminum, but I verified that it was actually an insulator). I suppose
a brush-like discharge is possible from highly charged nonconductive
surfaces, but I doubt we can pour fuel into this aircraft at rates
that will induces such high charge densities.
The other possibility is a discharge between the person and the
fuselage due to charge generated during flight due to air flow. But
again, this would be more like a brush discharge than a spark, and
would have to occur immediately after landing.
Most of the static discharge accidents I have read about have occurred
when the person touches the metal fuel nozzle.
I guess my question is, since there are no metal parts in the Europa
fueling system upstream of the tank, where does this spark occur to
cause ignition?
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grahamsingleton(at)btinte Guest
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Posted: Wed Dec 18, 2013 5:06 pm Post subject: Static in fuel system |
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I knew the owners of one of the fire victims (aircraft wsant written off) I think the static discharge was
between the metal tank breather on top of the Classic feselage and the metal funnel used to fill the tank.
The air rushes up the breather plastic tube and carries droplets in it picking up static charge on the way.
The discharge near the end of the filling cycle was to the metal funnel, earthed by the man's hand.
It was a dry hot day and aircraft had flown two hours.
I always recommend breath tube is bigger, 3/8" aluminum and grounded. Touching it with a hand will help.
Graham
The tank can be filled quicker with the bigger breather.
For the XS breather goes into the top of the cobra with a separate breather higher up, fuel splatter goes
back into the tank.
From: Andrew Sarangan <asarangan(at)gmail.com>
To: Europa List <europa-list(at)matronics.com>
Sent: Wednesday, 18 December 2013, 23:52
Subject: Static in fuel system
--> Europa-List message posted by: Andrew Sarangan <asarangan(at)gmail.com (asarangan(at)gmail.com)>
I hate to revive this discussion once again, but I am still trying to
figure out the static discharge mechanisms in the Europa fuel system.
I recall at least two Europas that were consumed by static induced
fuel fire. Was there any final report regarding these incidents, so
that we can learn from these?
Europa's fuel tank and the cobra inlet are nonconductive plastic. Even
the filler neck is non conductive (at first I thought this was
aluminum, but I verified that it was actually an insulator). I suppose
a brush-like discharge is possible from highly charged nonconductive
surfaces, but I doubt we can pour fuel into this aircraft at rates
that will induces such high charge densities.
The other possibility is a discharge between the person and the
fuselage due to charge generated during flight due to air flow. But
again, this would be more like a brush discharge than a spark, and
would have to occur immediately after landing.
Most of the static discharge accidents I have read about have occurred
when the person touches the metal fuel nozzle.
I guess my question is, since there are no metal parts in the Europa
fueling system upstream of the tank, where does this spark; http: -Mat Use ropa-List" target="_blank">http://www.matronics.com/Navigator?Europa-List> http://foru======================
[quote][b]
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asarangan(at)gmail.com Guest
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Posted: Wed Dec 18, 2013 6:58 pm Post subject: Static in fuel system |
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I see. I forgot about the stainless vent tube (I haven't got to that
stage yet). Mine is an XS, and the vent still goes to the top of the
fuselage.
So if the that piece of metal tube is a weak link, why not just
replace it with a rigid plastic tube?
On Wed, Dec 18, 2013 at 7:59 PM, GRAHAM SINGLETON
<grahamsingleton(at)btinternet.com> wrote:
Quote: | I knew the owners of one of the fire victims (aircraft wsant written off) I
think the static discharge was
between the metal tank breather on top of the Classic feselage and the metal
funnel used to fill the tank.
The air rushes up the breather plastic tube and carries droplets in it
picking up static charge on the way.
The discharge near the end of the filling cycle was to the metal funnel,
earthed by the man's hand.
It was a dry hot day and aircraft had flown two hours.
I always recommend breath tube is bigger, 3/8" aluminum and grounded.
Touching it with a hand will help.
Graham
The tank can be filled quicker with the bigger breather.
For the XS breather goes into the top of the cobra with a separate breather
higher up, fuel splatter goes
back into the tank.
________________________________
From: Andrew Sarangan <asarangan(at)gmail.com>
To: Europa List <europa-list(at)matronics.com>
Sent: Wednesday, 18 December 2013, 23:52
Subject: Static in fuel system
I hate to revive this discussion once again, but I am still trying to
figure out the static discharge mechanisms in the Europa fuel system.
I recall at least two Europas that were consumed by static induced
fuel fire. Was there any final report regarding these incidents, so
that we can learn from these?
Europa's fuel tank and the cobra inlet are nonconductive plastic. Even
the filler neck is non conductive (at first I thought this was
aluminum, but I verified that it was actually an insulator). I suppose
a brush-like discharge is possible from highly charged nonconductive
surfaces, but I doubt we can pour fuel into this aircraft at rates
that will induces such high charge densities.
The other possibility is a discharge between the person and the
fuselage due to charge generated during flight due to air flow. But
again, this would be more like a brush discharge than a spark, and
would have to occur immediately after landing.
Most of the static discharge accidents I have read about have occurred
when the person touches the metal fuel nozzle.
I guess my question is, since there are no metal parts in the Europa
fueling system upstream of the tank, where does this spark; http:
-Mat Use ropa-List"
target="_blank">http://www.matronics.com/Navigator?Europa-List>
http://foru======================
|
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ptag.dev(at)tiscali.co.uk Guest
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Posted: Thu Dec 19, 2013 12:22 am Post subject: Static in fuel system |
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Hi! Andrew,
So to eliminate the metal tubes and static weak link delete the metal tubes
and use an overflow catch bottle (with a return to tank plastic pipe link)
and carry the requirement for the vent over the top of the cabin down to
exit at the port side flap hinge in other words as far as reasonably
possible from the filler.
Regards
Bob Harrison G-PTAG
--
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