europa-list
[Top] [All Lists]

Re: Europa-List: Fuel vent position

Subject: Re: Europa-List: Fuel vent position
From: Fred Fillinger <n3eu@comcast.net>
Date: Wed, 23 Mar 2005 09:54:17

> ...
> How about some of you sending a few pictures to the
> Europa Owners site?
> ...
> Thanks!
> Brian Skelly

Not much to photograph, but for similar aesthetic reasons my primary
vent is a hole in the vertical fin leading edge, which is a short
pitot tube inside, with water trap using 1/4" nylon hardware.

I hope there's no airworthiness issue this way, other than no good for
IFR in icing conditions.  Good thing she's a homebuilt, as FAA
otherwise still requires icing tests even if not certificated for
"known ice!"  But it also makes it less important that my 2nd vent
line (through the fuel sender mounting plate) terminates in a flush
vent on the bottom of the aircraft, near the wing root.

The 2nd vent in this location could reduce what little positive
pressure there is at the main vent at low airspeeds during the
critical phases of flight.  To be tested soon, though.

Some production A/C with low wings have an arrangement which puts
positive pressure in the vent, even though a pump is still needed to
suck the fuel.  Guess they do so for good reason, though FAA rules
silent there.  Head pressure if fuel is low ain't much at all, and
perhaps this is to not aggravate a condition where the pump isn't
sucking too well (e.g., vapor lock).  PA-28 type airplanes get away
with some negative pressure in their vented cap setup though.

> While I am a number of chapters away from venting the tank and sight
tube...

If pressure in both tubes in the slipstream is not identical, said
sight gauge will be more useless in flight yet.  I have a sight gauge
also, but it's for visual check of quantity on the ground.  In the
corner behind passenger side seat upholstery; un-Velcro the seat back
to tilt forward and peek. It vents back into top of tank.

Reg,
Fred F.




<Prev in Thread] Current Thread [Next in Thread>