Mailing List flyrotary@lancaironline.net Message #22092
From: Perry Mick <pjmick@mail.viclink.com>
Subject: Fuel pump theory
Date: Wed, 18 May 2005 06:24:25 -0800
To: Flyrotary <flyrotary@lancaironline.net>
Sorry Ed, I'm doing this through web email, this is something Al Wick posted
to the Cozy group:

This news is so sad.

I want to advance this warning in case there are others with similar
installation:

I just glanced at the pic of construction of Pauls aircraft. Looks like
he had his fuel pumps mid firewall. This is not good. You need fuel pumps
as low on firewall as possible. This maximizes head pressure on fuel pump
inlet. Or putting it another way, it reduces your risk of vapor lock due
to inlet pressure drop. In addition, you want one fuel pump with no inlet
filtering, no fuel metering device. Both which increase pressure drop at
inlet. And most important, you want to measure the inlet pressure before
doing any flying. This will provide a number you can use to actually
measure your risk of vapor lock. Better yet, place fuel pump inside fuel
tank, then you have zero risk of vapor lock.

So I'm not saying this is the cause of his crash. I'm just warning others
of a substantial risk issue and how easy it is to overlook contributing
factors. I just hope fuel exhaustion was not a cause, it would bother me
a great deal. It already bothers me a great deal. He seemed like a great
guy.


-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html


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