Does anyone ever cap their fuel vent outlet?

kicktireslightfires

kicktireslightfires

Pre-takeoff checklist
Joined
Jun 11, 2020
Messages
348
Display Name
Display name:
kicktireslightfires
Just curious for those who leave their airplane out: Do you have a cover for the fuel vent in the same way you have one for the pitot tube? Where I live, small flying insects are a problem and I even need to put tape over my stall horn inlet as I found bugs going in there. I decided to put a cover on my fuel vent outlet, too, but it got me wondering: (A) Is that a bad idea for any reason and (B) would the smell of fuel make it very unlikely that any insect would go in there anyway?

Thanks in advance!
 
I put a flagged (red Mylar tape) doubled up pipe cleaner in mine. If I ever forget to remove them, enough air can get by to vent the tanks.
I’ve seen some people use RainBird irrigation system “dog n cat” filters and leave them in place.
 
Mud Daubers love fuel vents. I had covers for the vents on my Cardinal. Like said above, flag them. It can cause fuel starvation if left on and the gas caps aren’t venting. Not my plane but here’s a pic

upload_2021-4-10_16-40-8.jpeg
 
Thanks all! Just wanted to make sure that putting a cover on the vent wouldn't cause any adverse side effects if left out in the sun such as fuel vapor expansion with a sealed vent = over pressure.
 
On my plane (as a recommended procedure) I drilled a very small opening in the fuel vent line just above where it exits under the cowling. I do use a fuel vent cover but the small hole is there in the unlikely event that a bug gets into the vent opening during taxi or flight.

It's akin to a whistle slot in the oil breather tube but not nearly as large.

BTW ... I fly experimental so we be experimenting!
 
I bought one that has a fine mesh screen on the end of it. If you use a rubber cap, just put a slit or X in the end?
 
Just buy a bit of window screen and fold it, staple it and flag it.
 
Mud-dauber wasps have been known to block fuel vents in helicopters leading to fatals .
 
Quote from link ....
More common—at least in the accident record—are insects crawling into fuel vents. In the past few years, they’ve caused engine stoppages in Cessna 150s and 172s, a Commander 112, and a Bell 47 helicopter. A wasp made it all the way into the float bowl of a Piper Tomahawk’s carburetor; its head was found blocking the metering valve. And numerous irregularities under the cowling of a Beech Musketeer that lost power just after takeoff included “a golf-ball-size mud dauber wasp nest in the carburetor throat…cast[ing] doubt on the thoroughness of the pilot’s preparations and preflight inspection.”
https://www.aopa.org/news-and-media/all-news/2016/june/flight-training/accident-analysis
 
Daleandee said:
On my plane (as a recommended procedure) I drilled a very small opening in the fuel vent line just above where it exits under the cowling. I do use a fuel vent cover but the small hole is there in the unlikely event that a bug gets into the vent opening during taxi or flight.

It's akin to a whistle slot in the oil breather tube but not nearly as large.

BTW ... I fly experimental so we be experimenting!
Click to expand...

Fuel vent dumping into cowling? please explain the reasoning behind that.
 
A Martin said:
Quote from link ....
More common—at least in the accident record—are insects crawling into fuel vents. In the past few years, they’ve caused engine stoppages in Cessna 150s and 172s, a Commander 112, and a Bell 47 helicopter. A wasp made it all the way into the float bowl of a Piper Tomahawk’s carburetor; its head was found blocking the metering valve. And numerous irregularities under the cowling of a Beech Musketeer that lost power just after takeoff included “a golf-ball-size mud dauber wasp nest in the carburetor throat…cast[ing] doubt on the thoroughness of the pilot’s preparations and preflight inspection.”
https://www.aopa.org/news-and-media/all-news/2016/june/flight-training/accident-analysis
Click to expand...
A wasp would have to get past three screens to get into a carb float bowl, two of them exyremely fine mesh, and past the tiny float needle valve too. More likely someone assembled the carb castings without taking one last look inside and that wasp was in there then.
 
Wagondriver said:
Fuel vent dumping into cowling? please explain the reasoning behind that.
Click to expand...

Perhaps I wasn't clear. The fuel exit on my plane is brought out underneath the airplane where it exits the bottom cowling near the firewall.

Some builders place the vent on top but if you fly inverted there's a chance of getting fuel on the Lexan windshield and/or the Plexiglas canopy. To prevent that many builders run the vent line down the firewall and out the bottom of the cowling. It is then pointed into the wind to help pressurize the gravity fed fuel system.

Hope this helps ...
 
You must log in or register to reply here.
Back
Top