Kitfox lift strut fairings

[herman pahls]

I have been told that a member on this forum gained 10-12 Mph cruise on his 503 powered model 4 kitfox by adding lift strut fairings.
What improvement might I realize with a 80HP Jabiru and 520 pound model 1 Kitfox with 1 inch lift struts if I install strut fairings?
Does anyone have contact info for this member.
Thanks Herman Oregon 541 404 6464

[t j]

Originally Posted by herman pahls

I have been told that a member on this forum gained 10-12 Mph cruise on his 503 powered model 4 kitfox by adding lift strut fairings.
What improvement might I realize with a 80HP Jabiru and 520 pound model 1 Kitfox with 1 inch lift struts if I install strut fairings?
Does anyone have contact info for this member.
Thanks Herman Oregon 541 404 6464

Herman, that has to be me. I gained 8 to 10 mph cruise speed by installing the wing strut PVC fairing. It was about 75 mph without fairing and about 85 with fairing. I suspect with the 80 horse power you will get at least that much increase in speed.

My Model 4 weighed 561 before the fairing and 573 after.

[t j]

For Kodi, I saw your question on where I got the fairing but can't figure out how to reply there. I purchased the fairing from Kitfoxaircraftllc The fairing is on page 56 in the online catalogue. Here's a direct link to the catalogue.
http://www.kitfoxaircraft.com/Produc...-rev120810.pdf

[rogerh12]

Ya I saw a aerodynamic test on youtube, it clearly showed that a round tube has 9 times the drag of an aerodynamic tube with the same diameter. 9 TIMES !!!!

[herman pahls]

Tom
I appreciate your response including how much weight was added.
My original model 1 lift struts were 3/4 inch dia. with wooden fairings.
How complex are the PVC fairings to install?
I assume structual adhesive is used.
My concern is how to blend the PVC where the 2 struts merge.
Does the PVC get painted or covered with fabric?
Thanks Herman

[Mnflyer]

Hi Herman, I installed the PVC fairing on my Model III and it gave me a nice increase in cruise speed. The Model III also has 3/4" struts what I did was wrap the struts with wing leading edge tape (its about 4" wide and heavier than electrical tape) about every 16" wrapped it to 1" diameter. The PVC fairs just slip over the strut tube and snap together no need to glue them I just left the white no paint no fuss no muss. As for were they came together I just trimed them till the would fit on the aft ones it requires a longer taper so you don't hit the fuselage when the wings are folded I bent5 up some 0.020" alum and screwed it to the fairing to cover the taper opening. I did make strut cuffs for the top and bottom ends out of 0.020" alum, what I use for alum is roof flashing its available in 6" or 12" rolls in various lengths I use the colored (white) for some reason its 0.20" vs about 0.15" for the unpainted availible at home building suppliers like Menards.

[t j]

Herman, the PVC strut kit from Kitfoxllc comes with an aluminum cuff like described by Mnflyer. I used Polyfiber Super Fill to blend in the cut edges before installing the aluminum cuff. I painted with Fusion paint made for painting plastic.

The fairing was installed without removing the struts from the plane. It was fairly easy. The biggest job was masking the under side of the wing and fuselage before painting.

picture attached.

[Mnflyer]

Hi tj, thanks for posting the information and picture, I purchased my fairings from a individual and didn't get the factory cuffs, they look great and less work to install.

[herman pahls]

Thanks Tom and Mnflyer
I assume kitfoxllc is John and Debbie Mcbean.
I was not aware of a metal cuff to finish off the lower part of fairing so that helps alot.
Any photos of how to finish off the top of fairings at the wings???
Thanks Herman

[t j]

Originally Posted by herman pahls

Thanks Tom and Mnflyer
I assume kitfoxllc is John and Debbie Mcbean.
I was not aware of a metal cuff to finish off the lower part of fairing so that helps alot.
Any photos of how to finish off the top of fairings at the wings???
Thanks Herman

Yes, Kitfoxaircraftllc is the McBeans. I filled the top end of the fairing withsuperfill. Photo attached.

Here's a link to a a discussion on the fairing with some more ideas on finishing the ends. You can get as fancy as you want.
http://forums.matronics.com/viewtopi...685484a0b5a23c