Fuel Vent Intruder Alert!!

[chrispratt]

Some folks thought it was funny when I came up with fuel vent covers for my RV-8. But what I witnessed yesterday vindicated my efforts. I wouldn't have believed this if I hadn't seen it with my own eyes.

It was another windy day in North Texas and rather than fly I decided to do some maintenance. As I was looking at the airplane, one of my fuel vent covers was blown off by a wind gust. Within seconds, a flying intruder landed on the fuel vent and climbed up the opening. "You s&%ofa$#2," (I was applauding his precision landing ). I waited for him to back out of the tight location only to find he apparently liked it there.


(Click for larger view -- You can just see the stinger inside the opening)


Now I doubt that having that one little invader in there would block the fuel vent and cause my tank to crumple inward during flight -- but then again maybe it might. I didn't know if this little guy was going to deposit mud for a nest, or have babies that like to feed on 100LL.

So I spent the next hour taking the vent line off (gotta remove the cover which means removing the upper gear leg-fuselage fairing which means....you know the story.) Anyway the result is shown in picture number two below. Looks like a small yellow jacket or similar type with a nasty stinger.



So, if you don't cover your fuel vents now, you might want to reconsider especially during this time of year when bugs are building nests.

Chris

[Walt]

I've seen pitot ports totally plugged in 1 day by mud daubers.

Personally I prefer screens to prevent this stuff, they are 100% effective and you never forget to put them on

[rv7charlie]

I'll 2nd what Walt said. I flew a purchased -4 for about 5 years with uncovered vents, then one day upon landing/shutdown after a 15 minute flight, I heard a faint hissing sound. The right tank was sucked in slightly between all the ribs. I quickly popped open the fuel cap & the tank popped back out with no damage, but I still have no idea how the engine continued to run.

When I checked the vent lines, *both* had bee/wasp egg deposits, one about a foot up the line.

The vent inlets were short 90* bends of 1/4" tubing, cut with a tubing cutter & no removal of the cutter residue (actual opening less than 1/8"). I never worried about them before, thinking that the small hole size & gas fumes would protect me. Now I make sure that I've got screen over any vent lines.

Here in the Deep South, any opening between 1/8" (or smaller, as I discovered) up to around 1/2" will get plugged fairly quickly if it's left in an open area for more than a few days in the summer. If you've never been south before, consider yourself warned.

Charlie

[N941WR]

The newer kits recommend using a bulkhead fitting and cutting it at a 45° angle installed facing forward. A little proseal and some screen is all you need. After the proseal hardens, you can go back and trim the screen.

This will keep the bugs out and no need to put a vent cover on, or forget to remove one.

[jimbower]

Since the fuel vents on my -6A are bulkhead fittings cut at a 45, I just got some screw-on covers from Wick's and attached "Remove Before Flight" flags to them.

[airguy]

I have no idea what that insects proper name is, out here in West Texas we call them leaf-rollers. They will form a very tight plug in any small-diameter tubing that is left open, with tree leaf strips that they cut and carry in to make a nest. I've seen the nests in a 1/4" tube withstand 150psi air trying to blow them out, they make a very good seal.

And yes, they do have a rathy nasty stinger and they aren't afraid to use it. I put my hand down on a wood 2x4 once without realizing that one of these little guys had crawled into a hole drilled into the board under my hand, he proceeded to instruct me about the error of my ways.

[N8RV]

You know, that's one of those little tasks that I just sorta glossed over during the build. Thanks for the reminder, Chris. I think I'll glue some window screen material over my vent tubes this weekend ...

[Birkelbach]

I went to the aviation section of the local Lowes and bought some of those hose washers that have the stainless steel screen on them. If you cut 'em just right they make a perfect little screen for covering the vent line. A little pro-seal and some patience and they work great.

These have been flying on my plane for almost six years now in SE Texas and no plug-bugs, mud-dobbers or anything else has gotten in there.

http://www.myrv7.com/viewimage.php?pictureid=285

[F1Boss]

Take a length of .040 safety wire (maybe 1 1/2" or so) and fold it in half - leave it wide enough that it requires a 'press fit" - and push it into the opening in the vent line/fitting, with the folded end flush with the end of the vent tube/fitting. You will get plenty of venting action, and zero infestation problem, as the remaining 2 holes are too dang small for the critters to get in.

Cost of the equipment and time to install are not good excuses for this particular safety item. Get to it now!

Carry on
Mark

[David_Nelson]

No wonder the air drill just wasn't performing as it used to....