Jos and Glenn,
I have had the sight tube between the seats of my mono for about 800 hours
of flying now and it is totally reliable as a backup for the fuel computer
if certain measures are taken to keep the horizontal section of tube free
---From slugs of fuel.
I keep the sight tube vent separate right up to the filler neck so it is not
influenced by anything else. (Glenn, the fuel return line could bubble
vapour into the gauge and push fuel into the horizontal section, also is the
filler neck vent acting as a pitot and pressurising the tube when flying?
Have you forgotten to drill the little hole facing aft?)
I also have an on / off valve in the sight gauge tube where it tees into the
port side water drain at the tank entry point. This is necessary to stop
fuel from being pushed up the tube into the horizontal section when filling
the tank, because without it the sight tube acts as a another vent to the
tank when being filled. The gauge must of course be calibrated with the
port door sill horizontal so when the tail is on the ground it shows less
fuel than actual. If a slug of fuel gets trapped in the horizontal section
it will distort the gauge fuel level, because the air trapped above the fuel
level is unlikely to be at atmospheric pressure.
Hope that helps.
William
----- Original Message -----
From: "GLENN CROWDER" <gcrowder2@hotmail.com>
Sent: Saturday, September 30, 2006 5:20 PM
Subject: Re: Europa-List: Monowheel sight gauge
>
> I have routed my sight gauge identically and it works great on the
> ground, but
> in the air the fuel goes down in the sight gauge by about 3-4 gal. If I
> route the
> vent into my fuel return line at the top of the tank instead of the fuel
> tank breather
> tube, I get the same results so the sight guage is pretty worthless while
> flying.
>
> Glenn
>>From: "josok" <josok-e@ukolo.fi>
>>Reply-To: europa-list@matronics.com
>>To: europa-list@matronics.com
>>Subject: Re: Europa-List: Monowheel sight gauge
>>Date: Sat, 30 Sep 2006 13:30:46 +0300
>>
>>
>>Hi Ron,
>>
>>I decided to route the tube up the seatback, back in the seatback over the
>>tank, and up to the breather tube. The reason is that i will be able to
>>see the fuel level while tanking. The breather tube is connected to the
>>top of the filler and has it's opening behind the flap extension. You will
>>get the idea of the latter from the attached picture, where you see the
>>vent system. This is one of the good ideas of Graham Singleton. I am still
>>thinking of adding a one way valve there opening in the cockpit, to have a
>>second vent in case the primary one gets blocked.
>>
>>Kind Regards,
>>
>>Jos Okhuijsen
>>
>>
>>
>>
>>-------------------- m2f --------------------
>>
>>Visit - www.EuropaOwners.org
>>http://www.europaowners.org/viewtopic.php?p=12828#12828
>>
>>-------------------- m2f --------------------
>>
>>
>>Attachments:
>>http://www.europaowners.org//zfiles/img_2454_459.jpg
>>
>>
>>
>>
>>
>>
>
>
>
|
