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Kitfox mishap in Colorado
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Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Wed Dec 03, 2008 3:02 pm Post subject: Kitfox mishap in Colorado

Ya don't suppose they weighed it with the (pictured) pilot aboard, do  

ya? : )



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 593hrs

Sensenich 62x46

flying again after rebuild, and new Electroair direct-fire ignition  

system;

also building a new pair of snow skis

do not archive



On Dec 3, 2008, at 4:37 PM, Noel Loveys wrote:



 	  Quote: 	
		   Some, not all aircraft are certified to carry either 10% or more  

 commonly 100lb more if they are on floats.  The thinking here is at  

 cruise speed the floats passing through the air fly themselves  

 removing the excess weight from the plane’s structure.  I’m not  

 saying this is the case but I can say for sure my ‘Fox on Aerocet  

 1100s  doesn’t slip very well.  I think that specification has to  

 be made when the plane is first registered.



 BTW the extra pork on that plane hasn’t gone unnoticed...  I had a  

 reference to it offlist.



 Noel



 From: owner-kitfox-list-server(at)matronics.com [mailto:owner-kitfox- 

 list-server(at)matronics.com] On Behalf Of Kitfoxkirk

 Sent: Wednesday, December 03, 2008 2:37 PM

 To: kitfox-list(at)matronics.com

 Subject: Re: Kitfox mishap in Colorado

 How is it that the gross weight was increased by 10%? I asked about  

 this several years ago when I wanted to place my C IV on floats,  

 and received mixed answers.





 Thanks,



 ====================



 ============================================================

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Thu Dec 04, 2008 10:01 am Post subject: Kitfox mishap in Colorado

At 09:33 AM 12/3/2008, you wrote:

 	  Quote: 	
		  Boy, that is one obese Model IV. Even without Grove gear.


	


That's got to be a record for a IV. I wonder if it's a miss-print. 

Even with the bigger engine I don't see how you could add 230# to what I have.

Guy Buchanan

San Diego, CA

K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.



Do not archive

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Sat Dec 06, 2008 2:59 pm Post subject: Re: Kitfox mishap in Colorado

Guy is correct, being an experimental airplane, the builder can make the gross weight anything we wants....



I am going to have a gross weight of 2000 pounds on my Kitfox, just so that no one can ever ever accuse me of flying overweight should something happen

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Sun Dec 07, 2008 6:08 am Post subject: Kitfox mishap in Colorado

And if you do that, you'll have just lost a lot of potential buyers  

in the Sport Pilot category...IF you should ever decide to sell the  

plane.



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 593hrs

Sensenich 62x46

flying again after rebuild, and new Electroair direct-fire ignition  

system;

also building a new pair of snow skis





On Dec 6, 2008, at 5:59 PM, JetPilot wrote:



 	  Quote: 	
		   



 Guy is correct, being an experimental airplane, the builder can  

 make the gross weight anything we wants....



 I am going to have a gross weight of 2000 pounds on my Kitfox, just  

 so that no one can ever ever accuse me of flying overweight should  

 something happen 



 --------

 &quot;NO FEAR&quot; -  If you have no fear you did not go as fast  

 as you could have !!!



 Kolb MK-III Xtra, 912-S





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 17956#217956

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Mon Dec 08, 2008 2:45 pm Post subject: Kitfox mishap in Colorado

Just what I was thinking....  One other thing scrap the idea of putting on

an IFA prop.



Noel



--

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

aviateer

Joined: 08 Aug 2008
Posts: 23

Posted: Tue Dec 09, 2008 5:39 am Post subject: Kitfox mishap in Colorado

I understand about adjusting the gross weight to anything that you want. My question is, what types of dynamic loads can the airframe and wings sustain without damage in: calm air, turbulence, etc. if the aircraft has had it's gross weight increased. There are mechanical properties to address when one over grosses an aircraft. These are my concerns. 

   

 I know that aerodynamics change considerably (i.e. stall speeds, C.G., weight and balance) which in turn make the aircraft perform differently as well.  

  

 To my point, if one increases the gross weight, or overloads a Kitfox IV by 100 pounds, will there be structural damage incurred outside of calm air?

  

 Thanks,

  

 Kirk



 On Mon, Dec 8, 2008 at 4:44 PM, Noel Loveys <noelloveys(at)yahoo.ca (noelloveys(at)yahoo.ca)> wrote:

 [quote]--> Kitfox-List message posted by: "Noel Loveys" <noelloveys(at)yahoo.ca (noelloveys(at)yahoo.ca)>

 

Just what I was thinking....  One other thing scrap the idea of putting on

an IFA prop.



Noel



--

wingsdown(at)verizon.net
Guest

Posted: Tue Dec 09, 2008 8:02 am Post subject: Kitfox mishap in Colorado

I may  be coming in on this a bit late. But, the fact that someone decides to change or  make the gross weight of an aircraft to some number they have in mind has no  relevance to the design limits of the airframe. I think you most likely knew  this but some may not. The wings are tested to failure along with other  components of the airframe. Based on testing and equations beyond my ability to  use the limits are set.  It is never a good idea to fly over gross. Some do  with the false sense of security that a margin of safety is factored into the  limits set.  Testing is surely done in the air , though I doubt  seriously  that any are done intentionally with the idea in mind they will  see when the wings will fold or flutter destroys the airframe. Not that is has  not possibly occurred. 

 The whole topic is rather broad for sure. Staying with in the  design limits for gross weight, G loads , and airspeeds  is important for  survival. At least I think so.  If  you are at the edge of Vne in smooth air and hit that invisible bump, well hope  you make it.  

 One of  the best books I ever read on flying is called Stick and Rudder. It helps  one  to understand what is really going on with our aircraft in that  invisible ocean of air. 

  

  

 Rick

 [quote]   

       

[b]

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Tue Dec 09, 2008 8:28 am Post subject: Kitfox mishap in Colorado

My concern is a bit more down to earth.  As manufacturer of your airplane you are aware of what the plane can physically handle... It may be able to lift 1500 lb in calm air with no problems but don’t try it in 10 or 15 mph gusts at that weight.  As the builder you should be aware of that.  

But!  

As manufacturer of the aircraft you and even your estate are responsible for the safety of any one flying your plane.  This means anyone who may buy the plane from you in five or so years and fly according to your weight limitations.  Imagine, if you will, in ten years time your pride and joy has been sold twice.  The first sale was to a friend at the airfield who helped you build the plane...  He knows just about as much about that plane as you do.  Three years later he sells the plane to a flight school that wants a cheap plane for pilots to build time on their licenses.  Some day in early July a student and an instructor attempt a straight stall and have the wings fold around their ears because they had a takeoff weight of 1800lb. and happened to hit a gust while recovering from the stall.  Guess who is responsible for those two deaths even ten years after selling the plane...  you are still the manufacturer.  You will be held responsible.    

   

If anything I’d rate the plane below design specifications or only sell it as parts.  

   

Noel  

     

From: owner-kitfox-list-server(at)matronics.com [mailto:owner-kitfox-list-server(at)matronics.com] On Behalf Of Kitfoxkirk

 Sent: Tuesday, December 09, 2008 10:09 AM

 To: kitfox-list(at)matronics.com

 Subject: Re: Re: Kitfox mishap in Colorado  

  

     

I understand about adjusting the gross weight to anything that you want. My question is, what types of dynamic loads can the airframe and wings sustain without damage in: calm air, turbulence, etc. if the aircraft has had it's gross weight increased. There are mechanical properties to address when one over grosses an aircraft. These are my concerns.   

    

   

    

I know that aerodynamics change considerably (i.e. stall speeds, C.G., weight and balance) which in turn make the aircraft perform differently as well.    

    

   

    

To my point, if one increases the gross weight, or overloads a Kitfox IV by 100 pounds, will there be structural damage incurred outside of calm air?  

    

   

    

Thanks,  

    

   

    

Kirk  

    

On Mon, Dec 8, 2008 at 4:44 PM, Noel Loveys <noelloveys(at)yahoo.ca (noelloveys(at)yahoo.ca)> wrote:  

--> Kitfox-List message posted by: "Noel Loveys" <noelloveys(at)yahoo.ca (noelloveys(at)yahoo.ca)>

 

 Just what I was thinking....  One other thing scrap the idea of putting on

 an IFA prop.

 

 Noel

 

 --

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Tue Dec 09, 2008 9:08 am Post subject: Kitfox mishap in Colorado

When I was a kid and used to fly a lot with my father in his C-170 B on floats our normal takeoff weight was about fifty pounds over gross.  I flew for several years before I found out that the tails of the floats should not be under the water while taxiing.    

   

What he really needed was a bigger plane.  A C185 might have served him better.  When he went hunting in the fall he hired a DHC-2 beaver to fly him and his party into the hunting lodge and they would return ten days later to fly him out.  

   

The plane is still registered in Canada.  

   

Noel  

       

From: owner-kitfox-list-server(at)matronics.com [mailto:owner-kitfox-list-server(at)matronics.com] On Behalf Of Rick

 Sent: Tuesday, December 09, 2008 12:32 PM

 To: kitfox-list(at)matronics.com

 Subject: RE: Re: Kitfox mishap in Colorado  

  

  

     

I may be coming in on this a bit late. But, the fact that someone decides to change or make the gross weight of an aircraft to some number they have in mind has no relevance to the design limits of the airframe. I think you most likely knew this but some may not. The wings are tested to failure along with other components of the airframe. Based on testing and equations beyond my ability to use the limits are set.  It is never a good idea to fly over gross. Some do with the false sense of security that a margin of safety is factored into the limits set.  Testing is surely done in the air , though I doubt seriously  that any are done intentionally with the idea in mind they will see when the wings will fold or flutter destroys the airframe. Not that is has not possibly occurred.   

    

The whole topic is rather broad for sure. Staying with in the design limits for gross weight, G loads , and airspeeds  is important for survival. At least I think so.  If you are at the edge of Vne in smooth air and hit that invisible bump, well hope you make it.    

    

One of the best books I ever read on flying is called Stick and Rudder. It helps one  to understand what is really going on with our aircraft in that invisible ocean of air.   

    

   

    

   

    

Rick  

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_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

peteohms

Joined: 31 Oct 2007
Posts: 224
Location: Leander, TX

Posted: Tue Dec 09, 2008 12:04 pm Post subject: Kitfox mishap in Colorado

Kirk,  Let's say your Kitfox is good for 3.8  positive G's (at) 1050 lbs.  You overload it (accidentally of course) by 100  lbs.  Assuming the balance is ok, the plane is now only good for 3.5  G's.  Ok everybody, flame away. (But be civil)

  

 Pete

 Kitfox III N73BH SN 1000 912 grove

  

  

 [quote]   ---

_________________
Pete
Leander, TX
Kitfox III, 912ul, Grove

lowflyer

Joined: 10 Dec 2008
Posts: 8

Posted: Wed Dec 10, 2008 8:17 am Post subject: Re: Kitfox mishap in Colorado

Has anyone ever thought that maybe the builder of this aircraft has engineered the aircraft to accepted the increase in load? Maybe additional cross members on the frame, heavy duty gear, larger struts, etc, etc... 



I understand as a builder of a kit you have the freedom to change things. The manufacturer of the kit has set some guidelines as to what specs they have tested the kit to. If you want to go beyond these limits you can but you need to understand the implications associated with the increases. If you account for the increase in weight appropriately with additional modifications then you should be okay.



No one really knows why the increase was there and if it was accounted for by additional engineering and modifications.



Just a thought.



Chris Budd

N53RJ 

Model IV Speedster

76hp 2180 VW, 230hrs

wingsdown(at)verizon.net
Guest

Posted: Wed Dec 10, 2008 1:33 pm Post subject: Kitfox mishap in Colorado

Sounds great. Now some one out there post their modifications and

testing to verify the increased limits.



Rick



--

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Thu Dec 11, 2008 6:41 am Post subject: Kitfox mishap in Colorado

It was said the weight was increased so the pilot would never be written up

for overweight.  Nothing was said about modifications.

 



Noel Loveys

Campbellton, NL, Canada

CDN AME intern, PP-Rec

C-FINB, Kitfox III-A

912 almost installed

Aerocet 1100 floats

noelloveys(at)yahoo.ca





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_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

Roger Lee

Joined: 10 Jan 2006
Posts: 1464
Location: Tucson, Az.

Posted: Thu Dec 11, 2008 7:17 am Post subject: Re: Kitfox mishap in Colorado

Just a thought here guys before you jump.



The factory usually has the gross weight limits that they have tested on prototypes. If you add an artificially heavy weight that would be discoverable by an investigation especially if you injured someone in your plane you will be hanging in the wind in court and by the FAA. If you sold the plane that way and someone loaded more weight than the factory testing and you had it registered 500 or more lbs overweight you may be opening yourself up for a gross negligence law suit if someone gets hurt. You knowing and artificially over grossed the limits and never tested the new limits. A lawyer would eat you alive and if you have insurance they may baulk at paying for something you knew was artificial. Better to stay at least close to a factory tested weight unless you can show in the building plans where you added more structure to support additional weight. I have sat in many courtrooms and I can hear the lawyer now. Just protect yourself. Overly inflating the GVW could have consequences.

Doesn't even have to be the person you hurt a disgruntled family member could come and get you.

_________________
Roger Lee
Tucson, Az.
Rotax Instructor & Rotax IRC
Light Sport Repairman
Home 520-574-1080 TRY HOME FIRST
Cell 520-349-7056

lcfitt(at)sbcglobal.net
Guest

Posted: Thu Dec 11, 2008 8:10 am Post subject: Kitfox mishap in Colorado

Chris,



I think you bring up an interesting point.  For sure we don't know what 

exactly went in to the decision to increase the max gross wt.  But I think 

it is interesting that in almost every case of this happening, the builder 

has opted for an engine that is much heavier than the engines the airframe 

was designed for.  I have yet to see a Kitfox with a R-582 or 912 increase 

the gross wt, with the one exception - the increase allowable with floats. 

Regarding beefing up struts, landing gear, cross members in the frame etc., 

in my forced landing,  the beefed up landing gear survived the crash 

virtually unscathed.  It was sold intact by the salvage company.  I sort of 

wish that the landing gear would have absorbed more of the energy of the 

crash and maybe the airframe (and my back) wouldn't have taken all the 

grief.



I mention this because most engineered structures are engineered as a unit. 

Increasing any one component without reengineering the whole unit can focus 

stress at unintended points and rather than the whole structure absorbing 

stresses, the stresses can be focused at a single point and the structure 

can fail at below originally engineered stress levels.  I can't imagine that 

adding a cross member between two half inch .035 wall thickness longerons 

would increase the longeron strength.



Lowell



---

lowflyer

Joined: 10 Dec 2008
Posts: 8

Posted: Fri Dec 12, 2008 10:26 am Post subject: Re: Kitfox mishap in Colorado

Lowell,



I agree with you.  If you change a structure on your aircraft you are going to have to really study what the effect are on other areas of the aircraft. Your example of the landing gear shows this. I was just saying that with the right analysis you can safely make certain modification to your aircraft.  I also just wanted to give the builder the benefit of the doubt that maybe there was something more substantial behind his increase in gross weight. I personally wouldn't do this. As for the liability, no matter what you do, and no matter how perfect your aircraft was built. They can still come after you and blame it all on you. It's not right. There is not much you can do.



Fly safe



Chris Budd

53RJ 

Model IV Speedster

76hp 2180 VW, 230hrs

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