Mailing List flyrotary@lancaironline.net Message #18335
From: Russell Duffy <13brv3@bellsouth.net>
Subject: RE: [FlyRotary] Re: fuel cutoff valve necessary?
Date: Thu, 3 Mar 2005 20:53:27 -0600
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>
Message
When your electric system starts to act up, you might not be able to shut down your pumps! You still can stop your engine by cutting the fuel! 
 
You're reaching a bit here.  A fuel pump is an on/off device.  It's not like we have a bank of CPU's running the pumps :-) 
 
But keeping it to a part that is not really a shut off valve, like the fuel pump, no way! What if the pump shortens out/gets hot/leaks/etc. I want to be able to cut the fuel at the source! 
 
What if your fuel valve connections leak, or the shaft of the valve?  Then you're sucking air, which is a much more ominous problem. 
 
Everyone has their comfort level, so feel free to install a cutoff valve.  There are certainly situations where it could be needed, but for every one of those, I can come up with one where it's an extra danger :-) 
 
As a point of trivia, Van's specifically recommends against using braided hose in place of the normal aluminum tubing from the wing tanks.  The theory is that in an accident, the wings will be pulled back, and the fuel line will be torn loose.  The aluminum line will tend to pinch itself closed when it bends and breaks, but the braided hose will stay open when it breaks.  The difference is a big leak vs a small leak.  Van's not so dumb :-)
 
Cheers,
Rusty (my beer's empty)
 
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