KITFOX RADIAL

[EDMO 1078]

QUESTION: Just read article in EAA mag this month about Kitfox 7 Radial. How did they manage CG with a 235 pound engine when we are having to add ballast or LE extensions for our 200 pound Soobs? Anybody got an answer? IMO, a $75K experimental, like some other $100K LSAs has left us budget-builders out of the game.

Ed in MO

[akflyer 1427]

QUESTION: Just read article in EAA mag this month about Kitfox 7 Radial. How did they manage CG with a 235 pound engine when we are having to add ballast or LE extensions for our 200 pound Soobs? Anybody got an answer? IMO, a $75K experimental, like some other $100K LSAs has left us budget-builders out of the game.

Ed in MO

Not to be a smart ass... but.. moved the battery and added EVEN MORE LEAD. Engine mount is as short as absolutely possible also. She sounds awesome, and looks cool, but goes WAY beyond the realms of practical That being said, it would be a fun lil grocery getter, but not an every day driver for the back country. Kind of a who has the bigger johnson type thing...

With that being said. The kitfox was originally designed for the little radial engine that rotec promised they could make, hence the round cowling... But it never happened and was not practical.

[EDMO 1078]

Not to be a smart ass... but.. moved the battery and added EVEN MORE LEAD. Engine mount is as short as absolutely possible also. She sounds awesome, and looks cool, but goes WAY beyond the realms of practical That being said, it would be a fun lil grocery getter, but not an every day driver for the back country. Kind of a who has the bigger johnson type thing...

With that being said. The kitfox was originally designed for the little radial engine that rotec promised they could make, hence the round cowling... But it never happened and was not practical.

AND, The 210 pound 233? Not much improvement or performance gain here over the 170 pound, much cheaper, C-85, C-90, O-200 IMO, unless you need the fuel injection to get over the mountains. NOTE: Our highest "mountain?" here is 1700 MSL, and most mountain passes are less than 4000, so I've heard.

Don't know how long the Stratus mount is, but mine only leaves enough room to slip the fanbelt between the engine and firewall.

Ed in MO

Edited 27 Apr 2012 by Ed In Missouri

[Av8r3400 1179]

The newer Kitfoxes (5-7SS) are longer and designed to be able to use the small certified motors. The SS model can handle the 200+ pound motors okay. The motor mounts for the Rotax 912 in the new plane is quite long, allowing the oem intake plenum and a side mounted oil tank.

I find it funny that this plane hasn't existed in almost 2 years. (Takes that long for SP to publish anything any more...) This plane was dismantled to rebuild it to the Lycoming test bed, due in no small part to the poor performance and low reliability of the Rotec engine - from what I was told by one of the factory guys at the Kitfox booth last year. It generated considerable buzz from people who saw it (it was quite pretty) but apparently it was a bitch to fly. Very temperamental to start and went through loads of gas and oil. I was told on several occasions on the trip to and back from Oshkosh, it gave John (McBean) fits not only trying to start it but while flying in cruise.

The best way to deal with a heavy Subaru motor in an Avid is to do the stretch modification from Airdale on your fuselage...

[EDMO 1078]

The newer Kitfoxes (5-7SS) are longer and designed to be able to use the small certified motors. The SS model can handle the 200+ pound motors okay. The motor mounts for the Rotax 912 in the new plane is quite long, allowing the oem intake plenum and a side mounted oil tank.

I find it funny that this plane hasn't existed in almost 2 years.

The best way to deal with a heavy Subaru motor in an Avid is to do the stretch modification from Airdale on your fuselage...

I agree with all that you wrote.

I could have bought an Airdale years ago, and could have done the stretch - however, because of personal things, which I wont explain, a shortage of airplane cash, stubborness, hard-headiness, determination, and curiosity, I decided to do things a different way, by extending the Leading edges and increasing tail feathers, like Steve Wittman's designs, and other planes in the past.

I just hope that my way turns out to be workable, and flyable, when I am finished. I don't know if it is a "fix-all", but will share my findings in case it helps someone else if they are in a similiar position.

ED in MO

[SuberAvid 617]

Ed,

I know exactly what you are going through since I was at the same place trying to figure out what to do with my Avid MKIV to put a Soob on it. I am glad i decided to go with the Avid+ fusalage; not a "cheap" fix but at the time not too bad. The end result I am very happy with not just that it handles the Soob fine without any added ballast but the extra room in width, legroom and huge baggage area is amazing after flying my MKIV for so long. I don't have to worry about getting turbulent upset from the left and not being able to get enough left stick movement with my knee, hand, and stick as hard agains the door as possible but not enough room to move with the carharts on. A few of those had me uncomfortable in the past.

The mount I have on my Soob is as short as it could possibly be; the pully on the water pump only clears the FW by an inch and about 1/4 inch from the MM to FW bolt. It makes it difficult to work back there; I have to use a camming oil filter wrench on a ratchet extension to get to it and a pain to get the new one back on but it keeps the weight as far back as possible.

[EDMO 1078]

Ed,

I know exactly what you are going through since I was at the same place trying to figure out what to do with my Avid MKIV to put a Soob on it. I am glad i decided to go with the Avid+ fusalage; not a "cheap" fix but at the time not too bad. The end result I am very happy with not just that it handles the Soob fine without any added ballast but the extra room in width, legroom and huge baggage area is amazing after flying my MKIV for so long. I don't have to worry about getting turbulent upset from the left and not being able to get enough left stick movement with my knee, hand, and stick as hard agains the door as possible but not enough room to move with the carharts on. A few of those had me uncomfortable in the past.

The mount I have on my Soob is as short as it could possibly be; the pully on the water pump only clears the FW by an inch and about 1/4 inch from the MM to FW bolt. It makes it difficult to work back there; I have to use a camming oil filter wrench on a ratchet extension to get to it and a pain to get the new one back on but it keeps the weight as far back as possible.

I really liked the baggage / sleeping room in the Airdale. Great for Alaska, but don't camp out here. My fuselage has been widened six inches at the elbows. Still close with two on board. Got to go with what I have. Hopefully to welder this week, and working on LE extensions while it is gone to finish wings. I still carry the Carharts - but rarely need them here.

My boat seats set me six inches higher, and short legs are comfortable. Had to raise cabin roof six inches to compensate, so have a taller plane now. I really beefed up the landing gear attachments and tubes - seen too many bent there. Got Grove gear, and dont need anything bigger than 600 x 6 tires here.

Thanks for all the info.

Ed in MO

Edited 29 Apr 2012 by Ed In Missouri