REFLECTOR: Uneven Fuel Flow
Brooke Wolf
bwolf1 at tds.net
Thu Sep 29 08:41:30 CDT 2011
>
Ok, at the risk of showing my ignorance, I need to chime in here.
How could a minute leak in a fuel cap affect fuel flow out of a tank when that same tank has about a 3/8 inch hole in it vented to the outside (aka fuel vents)?
Brooke
>
>
> From: "John Abraham" <john at velocityaircraft.com>
> Date: September 29, 2011 8:06:09 AM EDT
> To: "'Velocity Aircraft Owners and Builders list'" <reflector at tvbf.org>
> Subject: Re: REFLECTOR: Reflector Digest, Vol 78, Issue 80 Uneven fuel flow
> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>
>
> 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:
>
>> Send Reflector mailing list submissions to
>> reflector at tvbf.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> http://www.tvbf.org/mailman/listinfo/reflector
>> or, via email, send a message with subject or body 'help' to
>> reflector-request at tvbf.org
>>
>> You can reach the person managing the list at
>> reflector-owner at tvbf.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of Reflector digest..."
>>
>>
>> Today's Topics:
>>
>> 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
>>>>>
>>>>> 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
>> -------------- next part -------------- An HTML attachment was
>> scrubbed...
>> URL:
>> <http://www.tvbf.org/mailman/private/reflector/attachments/20110928/df
>> 713c0d/attachment-0001.htm>
>>
>> ------------------------------
>>
>> 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>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> 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
>>
>> -------------- next part -------------- An HTML attachment was
>> scrubbed...
>> URL:
>> <http://www.tvbf.org/mailman/private/reflector/attachments/20110928/e1
>> a78e48/attachment.htm>
>>
>> ------------------------------
>>
>> _______________________________________________
>> Visit the gallery! tvbf:jamaicangoose
>>
>> End of Reflector Digest, Vol 78, Issue 80
>> *****************************************
>
> _______________________________________________
> 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
>
>
>
>
> _______________________________________________
> Visit the gallery! tvbf:jamaicangoose
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20110929/114a76c0/attachment-0001.htm>
More information about the Reflector
mailing list