It was an automotive application of plastic hydraulic lines (Lotus Elan, the
original not the later one with a reliable Japanese-built engine) that
convinced me to fit my Tri-Gear with stainless steel tubing outside the
fuselage and brass inside. Lotus routed the hydraulic clutch line close to
the exhaust and when that line ruptured, the ensuing fire nearly destroyed
the car. The other lesson learned was that a chemical fire extinguisher
(used by the professionals that arrived at the site in a large red truck)
can surely make a mess of the electrical components. Let's hope that Halon
remains available for aircraft use.
It was quite a chore for this novice tube bender to fabricate the metal
lines (especially since I also added brakes on the starboard side) but it
eliminated the unlikely but possible failure of plastic tubing.
Best regards,
Rob Housman
Europa XS Tri-Gear A070
Airframe complete
Irvine, CA
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of n3eu@comcast.net
Subject: Re: Europa-List: Hydraulic Line Advice???
> I was wondering if people have advice regarding tube selection
> and fittings for brake lines from the park brake to the gear
> legs? Any help greatfully received.
>
> Reg
> Tony Renshaw
> Sydney Australia
I used aluminum (soft 3030) tubing and AN fittings on my tri-gear. The
reason is fear (valid or not) that after setting my hydraulic parking
brakes, heat from the disc transfers to the cylinder, heats the fluid and
expands it. And by softening the plastic tubing, pushes it a bit out of its
connector each cycle, to someday pop on brake application. All I know for
sure is this heat phenomenon is real, as on the other plane it causes the
mechanical parking brake arrangement to lock up solid, so you have to invert
your body to go down behind the rudders pedals to release them, looking like
a dork on a busy airport ramp. The first certificated, production A/C I see
with plastic brake lines might modify my thinking here! Or automobile for
that matter.
Regards,
Fred F.
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