> An article earlier this year in Sport Aviation shows a diagram with the
> electric
> and mechanical fuel pumps in parallel, with the return line T'ing off the off
> the line just before the carb. They mentioned that it was a better way, but
> that the industry had gravitated to the pumps 'in-series' installation.
>
> Cleve Lee
> A198 Mono XS Jabiru 3300
>
That article was written by an opthamologist, who said that in vapor
lock, the vapor bubbles are too big to squeeze past the little needle
valve in the carb. While a good article overall, I mention this
because he implies that both the industry and FAA are wrong, regarding
a series system, because of this Big Bubble theory. I'd argue that a
parallel system of the type described is asking for trouble, but I'm
not an opthamologist. :-)
Whether or not the Rotax pump is a peculiar problem while other
versions are not can be answered with actual data. The following
Service Difficulty Report database tells me no; one SDR suggests the
Diamond Katana is a series system. NTSB also negative on fuel
blockage in the pump.
http://www.landings.com/_landings/pages/search/search_sdr.html
Gov't DB's are finicky, so one best enters only ROTAX912* under engine
model. Like gov't data also, there are 912-powered airliners (no
frills carrier?).
Regards,
Fred F.
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