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Re: REFLECTOR: Fuel tank venting
A simple check of the vent system by hooking an altimeter to the vent line
manifold should show if you have a positive (lower altimeter reading) or
negative (higher reading) pressure in the vent system. I agree with Duane that
the fuel cap should be the #1 check, however, checking the pressure at the vent
manifold is #2.
Duane Swing wrote:
> Fuel Venting Problem
> I totally agree with Jim Agnew on this one. Since it was not a
> persistent problem, I would suggest a fuel cap not seating properly and
> allowing a slight vacuum on one side stopping any fuel flow from that side.
> The single common vent system on the Elite almost always points to a fuel
> cap if uneven fuel flow is observed. I have personally seen a 1/2 full
> tank actually increase to 3/4 while the other one depleted far faster than
> the engine could use it. The best thing to do is always monitor your fuel
> system and land before fuel starvation ruins your day. If the problem does
> not go away, start checking fuel cap seals first.
> Sincerely, Duane Swing
> -----Original Message-----
> From: James F. Agnew [SMTP:Jim_Agnew@ibm.net]
> Sent: Tuesday, March 02, 1999 6:09 PM
> To: email@example.com; Carl Hoffman
> Subject: Re: REFLECTOR: Fuel tank venting
> This all sounds a little strange assuming that both tanks are connected to
> common vent. You will always get some fuel in your vent lines when you
> bank and
> the fuel is higher than the vent line. When you level out the fuel
> draining from
> the tank will create a partial vacuum that will suck the fuel/air into the
> Since the tank with more fuel (deeper) will have more output fuel pressure
> will always try to seek an even level with the other tank assuming a slight
> positive or neutral vent pressure evenly applied to both tanks. A water
> would not work if this was not true. Therefore, I would be suspicious of
> vent system possibly having some restriction on one leg or a leaking fuel
> allowing a slight vacuum in one tank.
> Carl Hoffman wrote:
> > Peter Beaty wrote:
> > >
> > > O-kay...
> > >
> > > What's the fix?
> > >
> > > At 05:37 PM 3/1/99 -0800, Scott Baker wrote:
> > > We believe that fuel must have entered the vent line
> > > >during the (initial) fueling of the aircraft and that the common
> > > >vent/pressurization was not strong enough to overcome the initial b
> > > >to this one tank. Just wanted to share.
> > > >
> > If there is a fix, how do you know it is a fix. Last week a "fixed" 737
> > had a uncommanded rudder excursion. The pilots are now trained to cope
> > with them. i.e. periodically check the level in both tanks.
> > Carl Hoffman
> // James F. Agnew
> // Tampa, FL
> // Velocity 173 FG Elite ( http://www.VelocityAircraft.com/ ) under
// James F. Agnew
// Tampa, FL
// Velocity 173 FG Elite ( http://www.VelocityAircraft.com/ ) under