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I am very close to first flight and am planning on doing it without the cover on the windshield for the fuel cap. I believe this will provide fresh air well away from the source of c.o. A friend expressed concern that there could be to much air velocity. I was wondering if any one had flown without the cover.

Why not do some CO monitoring in advance and deal with it on the ground? Flying with a cover off to guard against something that can be fixed on the ground doesn't seem wise.

Don't ignore the Law of Unintended Consequences.

Just my two cents, but I would run that idea by Kerry first. Contact tech support.

There are hundreds of 1st flights with these aircraft in the books already and these planes are naturally "leaky" from a cabin airflow perspective. Air comes in around the canopy, through the fuselage vents, from the wing roots, and from the rear spar carry-through areas. The aft fuselage is wide open and exhausts cabin air through the tail as well.

I was told that John Monnet was once asked why the turtledeck is not assembled outside, on top, of the upper aft fuselage skin instead of under it so that water would have a harder time getting in the airplane. His response was; "water gets in everywhere....it also gets out everywhere". I imagine that the air would do the same.

I suspect you are overthinking this item. Concentrate on flying the plane for your short first flight, (probably won't be longer than 30 or 40 minutes like most of us), and hang a co2 indicator on the panel to allay your concerns. Have a ball!

bipbuilder wrote:I am very close to first flight and am planning on doing it without the cover on the windshield for the fuel cap. I believe this will provide fresh air well away from the source of c.o. A friend expressed concern that there could be to much air velocity. I was wondering if any one had flown without the cover.

Hi, I have a definite opinion on flying without the fuel cap cover. But before I offer that up: what problem are you trying to solve? What other options have you considered?

Just to add another comment about the Onex fuel cap discussion .

Why do you want to fly without the cap in place? I have never flew my Onex with the cap off so I can't answer what the outcome would be....but what purpose does it serve to fly with it off?

I have a Naca vent on the right side of the fuse that feeds a 2" eyeball vent that pumps a LOT of air at cruise. It even pumps a fair bit while taxing or doing a runup.....so there is lots of fresh air available to counteract exhaust fumes if you think you have any. I do not.

Put the cap on and go fly the airplane. There is lots of other stuff to worry about in the first few hours of test flying.......just saying.

Gordon.........Hummel 2400....Onex #0024

The only problem I am trying to solve is in the middle of summer getting plenty of air circulation. I only mentioned the co as an extra benefit of the source of air is as far away from the co source as possible. I was considering the round windshield vents but not crazy about drilling another hole in the wind shield. I didn't think of naca vents until it was painted. I then realized there was an almost 4inch hole directly in front of me. Why not utilize it? Maybe I will start with an inch hole in the cover. I checked with sonex, they said it was a bit unusual but should be OK. As far as just flying it, I'd love to but I waited to long on paper work and now I'm waiting on the faa. I drug my feet to long because I was not wanting to send our billionaire govenor more tax money.

Onex Fuel Cap/Fresh Air Quandary ...?

Making a vent hole in the fuel cover is not the way to proceed.

The plastic vents in the windscreen (like the factory Onex) is a better option. If you do that than you need to remove the Lexan windscreen and lay it flat on a table and cut the holes with a "hole saw".

Another option (and a better one long term) is to install a Naca vent that feeds an "eyeball vent" in the cockpit. On the ground I have my 2"vent wide open but at cruise I have it closed down to half because it blows so much air.

I understand you have already painted the airplane. If you work carefully, you will be able to cut out the odd shaped hole for the Naca vent in the side skin without damaging the paint. If you want to email me I can give you more details on how to do that and some photos to show my installation.

Note: I would highly recommend to do this job that you remove the windshield, glare shield and fuel tank. Mine can all be removed in 20 minutes........then you have easy access to do this upgrade.

gdbaxter78@gmail.com

Gordon.........Hummel 2400.......Onex #0024

Gordon wrote:The plastic vents in the windscreen (like the factory Onex) is a better option. If you do that than you need to remove the Lexan windscreen and lay it flat on a table and cut the holes with a "hole saw".

I disagree. I was able to drill two holes for the plastic vents with the windscreen in place.