No real disagreement thar, but in overall context we may tend to
forget that the Europa has a single fuel tank, for reasons consistent
with its design philosophy. In FAA's hazard assessment philosophy,
redundancy trumps about everything else (including Burt Rutan's
imprimatur <g>).
I note that the Europa would not meet U.S. certification standards,
where if there's only one tank you must have two vents, but other
hazards still remain such as contamination. There's some suggestion
in a recent FAA (nonregulatory) doc that a nonredundant, critical
system should meet a standard of "ensuring that the Failure Condition
will not occur." That's a tough one, as even airliner certification
Regs. permit in places a finding of "extremely improbable." I wonder
what's on the Liberty to enable them to jump through the "will not
occur" hoop, if FAA wants to be that tough about it.
Regards,
Fred F., A063
Graham Singleton wrote:
>
> >Europa's method to mitigate water ingestion is the two 1/8" holes,
> >which I assume is OK, but I worry about me being too sloppy with a wax
> >rag in that area. Also, as it's metal tubing in the breeze, I figure
> >it will freeze much more quickly with altitude if enough H2O's
> >present, whereas my vent tube is "heat-sunk" to the fin, allowing more
> >time for airstream to purge it.
>
> The holes were recommended (by Burt Rutan) to avoid freezing. Water should
> run through with the continuous airflow. Any icing though has a bad effect
> on aerodynamics so is best avoided.
>
> Graham
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