kitfox 3 vs 4

[hannakt]

Hello the group,
I had one of the early to mid Model IIIs.
SN 1951 I think. ( Shamefully not finished yet ).

There were two variants of the Model III.
As I said, I had one of the early ones It was a Model III.
This model was later re-designated the Model III-1050 when the Model III-1200 was introduced.

I have two Model IIIs hanging in my hangar.
One is a Model III-1050 and the other is a Model III-1200
The -1050 is mine, the 1200 is an orphan. ( mostly mine - don't ask )

Flaperon attach points:
My -1050 had the AL flaperon brackets right off, these were not retrofits for me.

The Model III-1200 had two main differences:
1) Various reinforcements to allow for an increased GW ( 1200 lbs of course )
and
2) A thicker windshield so that the higher cruise would not cave in the lexan.

Under chamber:
Note: I can not speak of the Model IV, but the III-1200 also had the under cambered wing. You could get either the droop tips or the "Speedster" tips.
I got the "speedster" tips with mine.


Spar:
I do not know and have not measured the thickness of the spare tube material, but the diameter is the same as far as I can tell.

Spar "I" beam at the strut attach points:
My recollection, based on the rivet pattern, is that the reinforcements are about the same length between the 1050 and the 1200.
However I can not speak of the thickness of the "I" beam or the basic spar tube.

Lift Struts:
The III-1200 struts are significantly beefier than the III-1050.
I seem to recall that the threaded element on the ends of the struts are the next stud size up as well.

Carry throughs:
The cabin carry throughs are were beefier to allow for the higher GW.
These included the spar carry throughs on top as well as some of the tubes in the floor at the attach points for the struts and landing gear. The ODs of the tubing do not seem any different, so the differences must be in the gauges of the tubing walls. Makes it tough to tell which it might be.

Which one is it, a 1050 or a 1200???
The surest way is to look at the lift struts, if they are side by side, there is no missing the larger "look & feel" of the 1200 struts.

Assuming that all Model-IVs were -1200s ( I can't imagine anything else ), then from one of the earlier posts, it seems that the the easiest way to tell a -III for the -IV would be the under chambered wing.

Happy flying.
Kevin

[Av8r3400]

Kitfox never offered a III-1200. History

The 1200 didn't appear until the model IV, and then it was the later variation.

[Av8r_Sed]

Hi Kevin,
Your III's are most certainly Model IV's, one 1050 and the other 1200 gross.

The Model IV wing is more desireable than the undercambered III wing. You'll probably want to update your sale posting and put up some pics to go with it.

[hannakt]

I Humbly stand corrected.
Chalk it up to age and that it has been to many years since I have spent any time working on it. Sometimes it is nice to be just flat wrong. In this case, I have a IV-1050 instead of a -III. Not a bad way to be wrong.

I also concede on the "under cambered" wing.
I have not worked with other wings and there is a "slight" (1/2" ) of under camber in the wings I have. ( Along with the plastic nose extension ). But it clearly is not deeply under cambered like many of the Avids that I have seen.

Thanks for the corrections,
Sincerely,
Kevin Hanna

P.S. Thanks Av8r-Sed for the corrections.

[tinturtle]

I have N505KF which was built in 1993. It says it is a Kitfox 3 but has the Kitfox 4 flat bottomed wings and has the shaped (not flat)horizontal stabilizers in the tail feathers. I hear talk of short and tall rudders. I will measure mine tomorrow but meanwhile can somebody give me the dimensions of "Tall and Short'? Do I have a 1050 gross or 1200? A Kitfox 3.5?

[cap01]

I have model IV sn 1563 was delivered in November of 1991 and is a small tailed 1050. The construction manual is a mix of III and IV instructions . Sorry , don't have the measurements handy

[HighWing]

My 1992 Model IV-1200 rudder is 53" tall at the hinge.