I like to approach the problem by analyzing the possible failure modes. Not
knowing the exact function principle of the Pierburg pump from Rotax, I take
the assumption that at any time a pump could fail mechanically in a way that
the pump will not crate pressure and also will not block the fuel flow in
the reverse direction.In the original parallel design you are in trouble now
because you have a short circuit through the defective pump and you are no
longer able to maintain pressure.
The second failure could be: Clogging up filter elements. The two pumps in
series will produce a higher pressure. This could might be helpful if the
filter starts to clog up and might could still get you over the fence.
Just my penny of thoughts.
Michael Grass
A266 Trigear Detroit.
Building stopped, way to cold in Michigan
----- Original Message -----
From: "Simon Smith" <jodel@nildram.co.uk>
Sent: Wednesday, February 22, 2006 5:33 AM
Subject: RE: Europa-List: RE: 914 Fuel System
>
> I think that if there was a good reason for the pumps not to be in
> parallel
> then we would have seen an SB mandating the change to series.
>
> Simon
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of
> BEBERRY@aol.com
> Sent: 22 February 2006 09:25
> To: europa-list@matronics.com
> Subject: Re: Europa-List: RE: 914 Fuel System
>
>
> I have followed the recent parallel v series argument with interest. As
> the
>
> owner of a 914 with pumps in parallel and have no occasion in Europe to
> fly
>
> above say 7,000ft and then seldom, I wonder if some one more erudite than
> I
>
> could explain what problems I am likely to encounter and whether I should
> consider a modification?
>
> Patrick
>
>
>
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