REFLECTOR: Reflector Digest, Vol 78, Issue 80 Uneven fuel flow

John Abraham john at velocityaircraft.com
Thu Sep 29 07:06:09 CDT 2011 

Just an additional note to what Mark said.  If you have uneven fuel flow,
you should also check the lip of the fuel ring on your tank.  When you fill
up your tank or have an FBO do this for you if they hit the ring hard enough
with the nozzle and either dent it or score it your cap will also not close
properly.

5-7 gallons different per side is acceptable.  The tanks are fighting each
other by gravity pressure.  Also as a result of this if you are slightly out
of rig; even half a ball, over the course of 2-3 hours on a trip you will
have uneven feeding.  More than half a tank difference is unacceptable and
you need to land to see what is going on with your system.  You do not want
to wait until you are down to 3 gallons on one side while you have a full
tank on the other side anticipating for it to feed.

You also want to make sure that your low fuel warning light works.  You can
test it in flight without draining your tanks down.  Sometimes when you hit
turbulence it will flash the light on and off a few times.  Also, if you
stomp on the rudders back and forth 2-3 times it will make the switch
trigger, flash the light and go out.

Safe flying,

John

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Mark Riley
Sent: Wednesday, September 28, 2011 8:56 PM
To: reflector at tvbf.org
Subject: Re: REFLECTOR: Reflector Digest, Vol 78, Issue 80 Uneven fuel flow

On my XL I had uneven fuel flow and asked Duane Swing to take a look when we
stopped in Sebastian on the way to the Bahamas. He noticed two problems I
never would have caught. The O rings on the filler cap had minute flecks of
primer paint on them, which prevented them from creating an airtight seal.
Andy Millin and I spent an hour picking it off with our fingernails then
greasing them up with fuel lube. He also noticed that the gap around the
filler caps was too tight, so that it prevented the cap on one side from
seating properly. We just sanded it back ever so slightly until the cap
didn't rock at all when latched shut. If you try these fixes and still
wonder about your caps, you can try covering them with duct tape. Even a
minute problem like I've described can cause uneven drainage from the tanks
even in a properly rigged plane. 

Two more thoughts - first, it is not uncommon for the tanks to drain
unevenly but catch up to each other. One of my tanks always drains faster
between about 25 and 17 gallons, then the other one catches up. Second, if
the tanks get uneven, you can simply slip the plane for 1-2 minutes with the
uneven tank up. I find that they then drain evenly. I tried this for the
first time 100 miles from the nearest land on my way back to pick up the
Millins. Probably better to try it in a more comfortable setting first. 

Hope that helps.

Mark
On Sep 28, 2011, at 8:32 PM, reflector-request at tvbf.org wrote:

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> Today's Topics:
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>   1. Re:  STD RG Trim (Scott Derrick)
>   2. Re:  STD RG Trim (Glenn Babcock)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Wed, 28 Sep 2011 17:05:12 -0700
> From: Scott Derrick <scott at tnstaafl.net>
> Subject: Re: REFLECTOR: STD RG Trim
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Message-ID: <050fue2q67u5ay5mcgjyf6a6.1317254691797 at email.android.com>
> Content-Type: text/plain; charset="utf-8"
> 
> The unequal fuel born is because of the miss adjusted rudder trim.  The
fuel is acting as a really big BALL and is moving with the litttle ball.
> 
> Glenn Babcock <glennbabcock at roadrunner.com> wrote:
> 
>> Izzy,
>> 
>> Here's what I did:
>> 
>> - On the ground, level the plane.  Use a rotary laser level to level the
wings left to right, you can get one for under $100.  Put sawhorses or
something under the wings to hold the position.  Also level the plane front
to back.
>> - Verify that the wing incidence is correct for both wings using the
incidence gauge.  While you're at it verify the canard incidence.
>> - Verify the strake leading edge position on both sides.
>> - If needed, shim the wings and/or canard.  If the strakes are out that's
a more complicated fix!
>> - Now check that the TC is level (mine wasn't, making the problem look
worse than it was).  The ball should be right in the center.
>> - If you made no corrections in the wings or canard, shim the rudder (if
you made corrections, test fly first to see if it's still out).  I found
that you can hot glue bits of tongue depressor at the top, middle and bottom
of the rudder then trim them down as needed.  A small amount of shim makes a
big difference!  Make sure that the rudder touches all three shims when it's
resting.
>> - Also check the opposite rudder, you may be able to trim a SMALL amount
off of that side.
>> - Once you have the correct amount of shim, fill the gap with epoxy mixed
with micro glass or flox, then after it cures sand it till it's neat.  It's
very easy to do.
>> 
>> The fuel not draining evenly may be due to a leaking fuel cap.  Remove
the cap and coat the O-rings with Fuelube.  Make sure you get the little one
on the stem as well as the big one on the rim.
>> 
>> Regards,
>> Glenn
>> 
>> 
>> On Sep 28, 2011, at 9:06 AM, Dugas Bellsouth wrote:
>> 
>>> I did the same only used 1/16" angle aluminum. I trimmed a 1.5" so when
placed inside of the winglet it was flush with the airflow surface on the
fuselage side of the winglet. I the epoxied it to the inside of the winglet
and flew. Worked great. Still there and did not require all the glass work. 
>>> 
>>> Rene' Dugas
>>> Sent from my iPhone4
>>> 
>>> On Sep 27, 2011, at 5:56 PM, Scott Derrick <scott at tnstaafl.net> wrote:
>>> 
>>>> Trim the left rudder out until the ball is in the center.
>>>> 
>>>> Tape the vertical with duct tape near the lower part of the rudder.
Place a shim between the rudder and the vertical, about an 1/8 inch thick.
Then fill the gap with micro or epoxy glue, about 2 inches long, so it
sticks to the rudder.  Let cure, clean it up and fly. If that was to much
file the new tab down a bit and test fly again.  If the ball is still out,
add another 1/8 inch and test fly.  Do this until the ball is in the center.

>>>> 
>>>> Once you have the ball in the center, yaw trim, you can evaluate the
roll trim.   If the plane still wants to roll and the roll trim cannot
handle that you can shim both or one wing.  You usually want to shim the
light wing first by taking some of the aoa out of that wing by shimming the
lower bolt. If thta s not enough add in more aoa to the heavy wing by
shimming the upper bolts.
>>>> 
>>>> Scott
>>>> 
>>>> Izzy Brownfield <iznstacy at yahoo.com> wrote:
>>>> 
>>>>> I'm a new owner of a STD RG with io-360 three blade MT prop At 
>>>>> cruise T&B indicator is half ball to the left with a slight left turn
tendency. Fuel is consumed from the right tank at twice the rate of the left
tank.
>>>>> To center the ball it requires quite a bit of left rudder and light
right aileron pressure. 
>>>>> What adjustment is needed to be made to correct this?
>>>>> Thanks
>>>>> Izzy
>>>>> 5txo
>>>>> 
>>>>> Sent from my iPhone
>>>>> _______________________________________________
>>>>> To change your email address, visit 
>>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>> 
>>>>> Visit the gallery!  www.tvbf.org/gallery user:pw = 
>>>>> tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail 
>>>>> Check old archives: 
>>>>> http://www.tvbf.org/archives/velocity/maillist.html
>>>> _______________________________________________
>>>> To change your email address, visit 
>>>> http://www.tvbf.org/mailman/listinfo/reflector
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>> 
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> Message: 2
> Date: Wed, 28 Sep 2011 19:32:42 -0500
> From: Glenn Babcock <glennbabcock at roadrunner.com>
> Subject: Re: REFLECTOR: STD RG Trim
> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
> Message-ID: <F71FDCA0-9D0C-4A13-88A1-B6991DFA73A4 at roadrunner.com>
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> 
> It may be that or it may not, or it may be both.  I know that many people
have chased fuel flow problems all around the aircraft only to find the fuel
caps were leaking, causing a drop in pressure in one tank and restricting
fuel flow on that side.  A tiny amount of Fuelube and about 5 minutes effort
and the problem is solved.
> 
> Regards,
> Glenn
> 
> 
> On Sep 28, 2011, at 7:05 PM, Scott Derrick wrote:
> 
>> The unequal fuel born is because of the miss adjusted rudder trim. The
fuel is acting as a really big BALL and is moving with the litttle ball.
>> 
>> Glenn Babcock <glennbabcock at roadrunner.com> wrote:
>> 
>> Izzy,
>> 
>> Here's what I did:
>> 
>> - On the ground, level the plane.  Use a rotary laser level to level the
wings left to right, you can get one for under $100.  Put sawhorses or
something under the wings to hold the position.  Also level the plane front
to back.
>> - Verify that the wing incidence is correct for both wings using the
incidence gauge.  While you're at it verify the canard incidence.
>> - Verify the strake leading edge position on both sides.
>> - If needed, shim the wings and/or canard.  If the strakes are out that's
a more complicated fix!
>> - Now check that the TC is level (mine wasn't, making the problem look
worse than it was).  The ball should be right in the center.
>> - If you made no corrections in the wings or canard, shim the rudder (if
you made corrections, test fly first to see if it's still out).  I found
that you can hot glue bits of tongue depressor at the top, middle and bottom
of the rudder then trim them down as needed.  A small amount of shim makes a
big difference!  Make sure that the rudder touches all three shims when it's
resting.
>> - Also check the opposite rudder, you may be able to trim a SMALL amount
off of that side.
>> - Once you have the correct amount of shim, fill the gap with epoxy mixed
with micro glass or flox, then after it cures sand it till it's neat.  It's
very easy to do.
>> 
>> The fuel not draining evenly may be due to a leaking fuel cap.  Remove
the cap and coat the O-rings with Fuelube.  Make sure you get the little one
on the stem as well as the big one on the rim.
>> 
>> Regards,
>> Glenn
>> 
>> 
>> On Sep 28, 2011, at 9:06 AM, Dugas Bellsouth wrote:
>> 
>>> I did the same only used 1/16" angle aluminum. I trimmed a 1.5" so when
placed inside of the winglet it was flush with the airflow surface on the
fuselage side of the winglet. I the epoxied it to the inside of the winglet
and flew. Worked great. Still there and did not require all the glass work. 
>>> 
>>> Rene' Dugas
>>> Sent from my iPhone4
>>> 
>>> On Sep 27, 2011, at 5:56 PM, Scott Derrick <scott at tnstaafl.net> wrote:
>>> 
>>>> Trim the left rudder out until the ball is in the center.
>>>> 
>>>> Tape the vertical with duct tape near the lower part of the rudder.
Place a shim between the rudder and the vertical, about an 1/8 inch thick.
Then fill the gap with micro or epoxy glue, about 2 inches long, so it
sticks to the rudder.  Let cure, clean it up and fly. If that was to much
file the new tab down a bit and test fly again.  If the ball is still out,
add another 1/8 inch and test fly.  Do this until the ball is in the center.

>>>> 
>>>> Once you have the ball in the center, yaw trim, you can evaluate the
roll trim.   If the plane still wants to roll and the roll trim cannot
handle that you can shim both or one wing.  You usually want to shim the
light wing first by taking some of the aoa out of that wing by shimming the
lower bolt. If thta s not enough add in more aoa to the heavy wing by
shimming the upper bolts.
>>>> 
>>>> Scott
>>>> 
>>>> Izzy Brownfield <iznstacy at yahoo.com> wrote:
>>>> 
>>>>> I'm a new owner of a STD RG with io-360 three blade MT prop At 
>>>>> cruise T&B indicator is half ball to the left with a slight left turn
tendency. Fuel is consumed from the right tank at twice the rate of the left
tank.
>>>>> To center the ball it requires quite a bit of left rudder and light
right aileron pressure. 
>>>>> What adjustment is needed to be made to correct this?
>>>>> Thanks
>>>>> Izzy
>>>>> 5txo
>>>>> 
>>>>> Sent from my iPhone
>>>>> _______________________________________________
>>>>> To change your email address, visit 
>>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>>> 
>>>>> Visit the gallery!  www.tvbf.org/gallery user:pw = 
>>>>> tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail 
>>>>> Check old archives: 
>>>>> http://www.tvbf.org/archives/velocity/maillist.html
>>>> _______________________________________________
>>>> To change your email address, visit 
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>>>> 
>>>> Visit the gallery!  www.tvbf.org/gallery user:pw = 
>>>> tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail Check 
>>>> old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>> _______________________________________________
>>> To change your email address, visit 
>>> http://www.tvbf.org/mailman/listinfo/reflector
>>> 
>>> Visit the gallery!  www.tvbf.org/gallery user:pw = 
>>> tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail Check 
>>> old archives: http://www.tvbf.org/archives/velocity/maillist.html
>> 
>> _______________________________________________
>> To change your email address, visit 
>> http://www.tvbf.org/mailman/listinfo/reflector
>> 
>> Visit the gallery!  www.tvbf.org/gallery user:pw = tvbf:jamaicangoose 
>> Check new archives: www.tvbf.org/pipermail Check old archives: 
>> http://www.tvbf.org/archives/velocity/maillist.html
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