vented fuel caps

Hello everyone! Tonight my flight instructor was watching me do the pre-flight and started asking questions about the forward facing vented fuel caps on my series 6. His thoughts were, since it had a mechanical fuel pump why cant the vents be faced to the rear (aft) his concerns were dirt, bugs, and water contamination. I thought they faced forward for positive fuel pressure along with the help of gravity. I might call John at kitfox and ask him this question also!

Thanks in advance
Patrick Series 6
912 100hp tri-gear
Flight training

Those vents should keep the engine running if that fuel pump dies. If they are pointed forward, that is. Jim Chuk

Is there a possibility of siphoning, if pointed aft?

Patrick,

Only put the cas caps on with the vent pitot pointing into the wind as designed.......that will reduce the possibility of acquiring 15 minutes of fame with the NTSB........You are doing it right to begin with.

Much thought has gone into the design of the Kitfox fuel system that we now have on our birds.

The fuel caps are on my checklist......gasket OK.....blow through the pitot......correct installation. - The pitot is an avenue of getting stuff into the fuel system....that is why it gets checked on preflight and that is one reason why the header tank with it's sump drain and proper filters are used on the plane.

A year or so ago I included some photos on the list which showed what I found in the bottom of the header tank after flushing and filtering the rinsate ....suprisingly little,...barely a pinch....my microscope revealed the small amount of crud was composed of insect parts, some soil particles and grass (the kind cows eat - not the colorado stuff) ...I have no idea where the grass particles came from:rolleyes: but there seems to be some of that stuff on my gear too.

I always open my fuel filter when swapping it out....I have never found anything in the filter pleats....just the pinch of stuff in the bottom of the header tank and that is with quite a few gallons of gas going through the system. I have had very little occurance of water in the system. The few drops that I have found come out of the header tank drain or wing tank drain and are more often related to temp changes/condensation humidity.

I do use a tractor funnel with a chamois spread over the top when fueling at the hangar....that catches small stuff that can be in the gas (water & non-descript small particles)

Cheers,

Dave S
KF 7 trigear
912ULS Warp Drive

I believe the position of the fuel cap pitot is important. Once, when I flew to the Kitfox Factory, John McBean looked fairly closely at my plane. He was kind enough to make a couple minor adjustments for me that I didn't realize needed adjusting. One of those things was to straighten the fuel cap pitots so they pointed directly forward. One had been bent slightly to one side.

Skysteve,

You gring up another subtle yet important issue.

I found in testing that my fuel cap pitots were just a little off being square with the world.....enough that it affected which tank drained a bit faster,

Straightening them so they pointed directly forward fixed that.
Sincerely,

Dave S
KF7 Trigear
912uls Warp Drive

This sort of reminds me of the time I ferried a friend up to Quincey where the Stearman Expert did his work. It was to pick up his plane after an annual. The Stearman guy didn't like my tail wheel set-up. I had 700 uneventful hours on the airplane with at least as many landings so ignored his advice.

Lets see, 4000 Kitfoxes sold. Maybe 3000 flying. Lets say 50 hours a year each over ten years - average. Lots of history. Same fuel cap design from day one.

And Kitfox has never been timid about service letters and bulletins.

Not a problem.

Yes it will syphon gas out of your tank, and at the price of 100LL. I wouldn't really want to see to much stain on my wings or horizontal stabilizer. It is a very expensive stain!

How many hours does your instructor have in Kitfoxes. My kit fox "instructor" broke a prop, rudder spring, rudder, tailwheel and caused me an ELT activation. Call a Kitfox instructor. This aint your daddys taildragger.
Happy skies.