Fabric Covering begins...

[EricP]

This is what comes to my mind when I see the aft fuel lines routing uphill and down the fwd posts along with the fwd lines.

In a climb attitude (which would be more than this, this is just 13 degrees) when the forward tank port gets uncovered you will starve the engine of fuel. Since these lines are combined below at the tee you can't maintain a siphon on the aft line, air will travel down through the forward line, through the tee, and back up the aft line as the weight of fuel in that line pulls the air along with it.

Just my take, but I would probably redo the lines so there was a positive head pressure at all flight attitudes as is achieved with the original design.

ETA: I don't think there's a problem with not having a "Both" option, other than you can't manually balance tanks which I wouldn't see being too big of an issue.

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I will check on the actual routing to see if this is an issue.

[Archer39J]

I reread your post describing your fuel system layout. These are significant modifications to the fuel system. As it stands currently you cannot fulfill the recommended minimum fuel flow requirements for our aircraft, being minimum fuel in the tanks at +5 degrees from maximum pitch angle. In this configuration your system would be providing 0 GPH.

For injected engines this should be 125% the maximum fuel needed by the engine at full power.

See:

https://www.law.cornell.edu/cfr/text/14/23.955

https://www.faa.gov/documentlibrary/media/advisory_circular/ac%2090-89a.pdf

We ARE experimental, but modification of the fuel system and deviation from recommended guidelines is not where I would experiment.

Apparently some FISDOs are asking for fuel flow test results too, which is a good idea IMO.

[EricP]

I went over the Eric Newton books last night on the fuel system and then talked with Brent (my building partner). After going over things we both agree that the fuel lines will have to be redone. Brent was working on the installing the fuel lines and wiring. I guess I didn't get "engaged" enough while I was doing fabric work. At any rate, while I had looked at the fuel system some time ago I was not paying attention to it now and I guess Brent thought we could improve the ergonomics as we don't like the position of the fuel selector on the floor. However, what he devised simply won't work either. So...

1. The fuel tanks themselves and everything for the wings are OK, just like the plans, to specs. So no issue with the fuel tanks.

2. The fuel line routing he chose does not work for all angles of flight and we will be changing the fuel line routing. This will require some amount of ripping out and rebuilding. At this point I don't know how much.

3. From what I can tell we have used the correct equipment but not properly installed.

My thanks to those that correctly saw the issues and brought them up to me.

We also just found out that the person we thought would be able to help us with the set up on the avionics isn't going to work so we have scheduled with someone else. Of course that is going to create a delay... Which now gives us time to fix the fuel line routing.... Sigh...

[Bdflies]

Congratulations! You've initiated the most difficult manuver for a pilot: The 180 degree turn.

I did that once.....

Bill

[SimonNicholson]

Here are the first pics of our initial attempts at fabric work. We started with the interior of the doors, since they aren't "airworthy" items! We are definitely are on the learning curve but getting better as we go. I'm sure we will come back for more work on the cosmetics. We plan on trimming the area that opens for the door latch with some sort of nice trim ring to pretty it up. I want to add "patches" to the corners where the fabric goes under the cross brace.

We are liking how the Oratex fabric is working out so far. Very nice that it is pre-painted. We just cut, glue and heat shrink. It is done at that point!

Hi Eric.

How much fabric do you use to cover your interior alone?

Simon

[EricP]

Sorry, I didn't keep track. I can go check our initial order to see how much total we bought. So far we have not ordered any more. However, since our realizing we are going to have to completely change the fuel line routing we will be having to redo some of the interior once the fix is completed.