Vixen Vertical Stab Mod?

[tim.green]

I'm new to the community - this is my first post.

My brother and I are completing a Kitfox Model 5 Vixen. We're lifelong aviation buffs - we've built a gazillion model airplanes, he's a pilot, we're both pretty mechanically inclined.

Our kit was started by another builder 15 years ago. It's mostly built and almost ready for covering.

We'd like to do away with the sheet aluminum dorsal fin and replace it with a more typical Kitfox curved vertical stab leading edge.

We'd like to do this for cosmetic reasons - would there be any adverse effects on the plane's flight characteristics?

Any suggestions on the best way to do this? Is fabricating a new leading edge from 4130 chrome-moly tubing and welding it to the existing one the way to go? Are there other possibilites?

I'd appreciate any suggestions!

[HighWing]

I know of at least three guys that have done as you suggested, but on Model IVs, I know of one that used aluminum tubing glued to the fuselage near the turtle deck and with a thin plywood stiffener under it to accommodate the fabric tension. All glued with Hysol. The other - me - just used the aluminum tube, but extended forward to just aft of the antenna mounting plate with no plywood stiffener. Both faired in with Micro. The first eliminates the possibility of antenna mounting on the uppsr surface of the fuselage and that is what I wanted to preserve. I am covered and painted and the aluminum held it's shape under the fabric tension, the aluminum tube is there to stay.

Lowell

Just re-read the original post and forgot to comment on the flight characteristics. The two mentioned have not flown yet but the third is flying with no adverse characteristics.

[DanB]

Tim,
I did the dorsal mod to my IV and it turned out fine using the tubing. This has been done on several planes here in Desert Fox Squadron and they all fly great.
Here is a link that shows what was done. http://www.azshowersolutions.com/Dorsal.html

Best Wishes

[enyaw]

Here's what a S7 SS has following plans (alm. tube, plywood w/lightning holes). I would think that Series 5 should have similar flight characteristics.

Wayne

[tim.green]

Thanks for the replies everyone - we appreciate the help! To summarize:

1. It's doable and been done
2. There's a number of approaches that work
3. It produces no to little effect on flight characteristics

Next question - on the 5, the horizontal stab moves to provide pitch trim, so there's slot or the leading edge of the stab to move up and down in. The trailing edge of this slot is formed by an aluminum sheet piece. Normally the leading edge of the slot is formed by the aft edge of the turtle deck (which we're replacing!). Any ideas on how to form the this slot without the t-deck? How does it work on the 7?

Thanks!