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kenharrison

Joined: 06 Aug 2008
Posts: 4
Location: Lancaster, SC

Posted: Mon Dec 22, 2008 7:11 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

What is the best way to keep the fiberglass seat from cracking?  Mine has very small cracks that are right at the outside edges both sides, basically half way up the back.  It makes a crackling sound every time I get in.  I have re-enforced the seat with some seat belt material underneath but was wondering if anyone has a better solution.  

 

 I am going to repair the fiberglass and thought I’d check to see if anyone has dealt with this problem.  I don’t want to make the fiberglass repair and then just have it crack again in the same place.  

 

 I’ve read about the seats failing and jamming the controls...always in the back of my mind.

 

 Thanks,

 Ken

 

       [quote][b]

_________________
Ken Harrison
Kitfox III
Rotax 582 C Box
Powerfin 3-Blade

dan(at)azshowersolutions.
Guest

Posted: Mon Dec 22, 2008 7:32 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Ken,

If you are thinking about making repairs you could really strengthen critical areas if you used carbon fiber instead of fiberglass...just a thought.

Dan B

Mesa, AZ

--- On Mon, 12/22/08, Ken Harrison <kenharrison(at)comporium.net> wrote:



 	  Quote: 	
		   From: Ken Harrison <kenharrison(at)comporium.net>

 Subject: Kitfox III Fiberglass Seat Pan Cracking

 To: "Kitfox List" <kitfox-list(at)matronics.com>

 Date: Monday, December 22, 2008, 8:11 AM

 What is the best way to keep the fiberglass seat from

 cracking?  Mine has

 very small cracks that are right at the outside edges both

 sides, basically

 half way up the back.  It makes a crackling sound every

 time I get in.  I

 have re-enforced the seat with some seat belt material

 underneath but was

 wondering if anyone has a better solution.

 

 I am going to repair the fiberglass and thought I¹d check

 to see if anyone

 has dealt with this problem.  I don¹t want to make the

 fiberglass repair and

 then just have it crack again in the same place.

 

 I¹ve read about the seats failing and jamming the

 controls...always in the

 back of my mind.

 

 Thanks,

 Ken

sbennett3(at)aol.com
Guest

Posted: Mon Dec 22, 2008 7:33 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Ken, I don't have suggestions to help you fix your seat issue, just a reminder that there are control rods running under that seat that if collapsed on will keep you from being able to control ailerons.  I had that happen to me once. Maybe a new seat can be on your Christmas list.  Personally, i'd replace it.  Steve Bennett  classic 4 912ul... Durham NC

  

  

  

 In a message dated 12/22/08 10:12:44 Eastern Standard Time, kenharrison(at)comporium.net writes:

  	  Quote: 	
		     .aolmailheader          {font-size:8pt; color:black; font-family:Arial} a.aolmailheader:link    {color:blue; text-decoration:underline; font-weight:normal} a.aolmailheader:visited {color:magenta; text-decoration:underline; font-weight:normal} a.aolmailheader:active  {color:blue; text-decoration:underline; font-weight:normal} a.aolmailheader:hover   {color:blue; text-decoration:underline; font-weight:normal}  What is the best way to keep the fiberglass seat from cracking?  Mine has very small cracks that are right at the outside edges both sides, basically half way up the back.  It makes a crackling sound every time I get in.  I have re-enforced the seat with some seat belt material underneath but was wondering if anyone has a better solution.  



I am going to repair the fiberglass and thought Iâ€™d check to see if anyone has dealt with this problem.  I donâ€™t want to make the fiberglass repair and then just have it crack again in the same place.  



Iâ€™ve read about the seats failing and jamming the controls...always in the back of my mind.



Thanks,

Ken



 	  Quote: 	
		  



	


	
  

 Listen to 350+ music, sports, & news radio stations – including songs for the holidays – FREE while you browse. Start Listening Now!

   [quote][b]

msm_9949(at)yahoo.com
Guest

Posted: Mon Dec 22, 2008 8:21 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Ken, There will always be varying opinion on such issues so here's mine, FWIW: You've apparently already addressed the safety issue by installing webbing straps. These are, in reality, now supporting the weight of the seat pan and it's occupants. If you've done this job properly (as I'm sure you have) so long as the webbing is intact, the seat pan will not fail. So, my humble advice would be to repair the cracks in the pan and carefully inspect pan, webbing and its attachment points at each annual.

  

 Marco Menezes N99KX

 Model 2 582-90 C-Box 3:1 w/clutch

  

 

--- On Mon, 12/22/08, sbennett3 <sbennett3(at)aol.com> wrote:



  	  Quote: 	
		  From: sbennett3 <sbennett3(at)aol.com>

Subject: Re: Kitfox III Fiberglass Seat Pan Cracking

To: kitfox-list(at)matronics.com

Date: Monday, December 22, 2008, 10:32 AM



  Ken, I don't have suggestions to help you fix your seat issue, just a reminder that there are control rods running under that seat that if collapsed on will keep you from being able to control ailerons.  I had that happen to me once. Maybe a new seat can be on your Christmas list.  Personally, i'd replace it.  Steve Bennett  classic 4 912ul... Durham NC

  

  

  

 In a message dated 12/22/08 10:12:44 Eastern Standard Time, kenharrison(at)comporium.net writes:

  	  Quote: 	
		     #yiv123930800 .aolmailheader          {font-size:8pt;color:black;font-family:Arial;} #yiv123930800 a.aolmailheader:link    {color:blue;text-decoration:underline;font-weight:normal;} #yiv123930800 a.aolmailheader:visited {color:magenta;text-decoration:underline;font-weight:normal;} #yiv123930800 a.aolmailheader:active  {color:blue;text-decoration:underline;font-weight:normal;} #yiv123930800 a.aolmailheader:hover   {color:blue;text-decoration:underline;font-weight:normal;}  What is the best way to keep the fiberglass seat from cracking?  Mine has very small cracks that are right at the outside edges both sides, basically half way up the back.  It makes a crackling sound every time I get in.  I have re-enforced the seat with some seat belt material underneath but was wondering if anyone has a better solution.  



I am going to repair the fiberglass and thought I’d check to see if anyone has dealt with this problem.  I don’t want to make the fiberglass repair and then just have it crack again in the same place.  



I’ve read about the seats failing and jamming the controls...always in the back of my mind.



Thanks,

Ken



 	  Quote: 	
		  



	


	
  

 

  Listen to 350+ music, sports, & news radio stations – including songs for the holidays – FREE while you browse. Start Listening Now!

 	  Quote: 	
		  



blank rel=nofollow>http://www.matronics.com/contribution

arget=_blank rel=nofollow>http://www.matronics.com/Navigator?Kitfox-List

=nofollow>http://forums.matronics.com

	


	


         [quote][b]

wingsdown(at)verizon.net
Guest

Posted: Mon Dec 22, 2008 8:49 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Even  before any cracks developed I too reinforced the pans with carbon fiber.   Good idea,

  

 Rick

 [quote]   

   --

Float Flyr

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

Posted: Mon Dec 22, 2008 8:49 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

To get the strength to weight you should have there the only way is to vacuum bag the repair and carefully weigh the amount of resin you put into the cloth.  For something that needs to be strong like a seat I think I’d even go with pre-preg cloth with the nap running 45Deg on each layer.  Finding someone with a autoclave or a hotshot will be the major problem.  

   

Noel  

       

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

 Sent: Monday, December 22, 2008 11:41 AM

 To: Kitfox List

 Subject: Kitfox III Fiberglass Seat Pan Cracking  

  

  

   

What is the best way to keep the fiberglass seat from cracking?  Mine has very small cracks that are right at the outside edges both sides, basically half way up the back.  It makes a crackling sound every time I get in.  I have re-enforced the seat with some seat belt material underneath but was wondering if anyone has a better solution.  

 

 I am going to repair the fiberglass and thought I’d check to see if anyone has dealt with this problem.  I don’t want to make the fiberglass repair and then just have it crack again in the same place.  

 

 I’ve read about the seats failing and jamming the controls...always in the back of my mind.

 

 Thanks,

 Ken   	  Quote: 	
		    http://www.matronics.com/contribution 	
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       [quote][b]

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

Lynn Matteson

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

Posted: Mon Dec 22, 2008 10:39 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Here's another idea....install under-seat tool boxes. John & Debra  

McBean sell them I'm sure. Either there or Murle Williams. I got two  

of 'em and installed them and I seem to recall that they will contact  

a diagonal member of the fuse before anything hits the control rods.

Talk about killing two birds....now you've got places to put more crap!



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

Sensenich 62x46

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

system;

also building a new pair of snow skis





On Dec 22, 2008, at 11:20 AM, Marco Menezes wrote:



 	  Quote: 	
		   Ken, There will always be varying opinion on such issues so here's  

 mine, FWIW: You've apparently already addressed the safety issue by  

 installing webbing straps. These are, in reality, now supporting  

 the weight of the seat pan and it's occupants. If you've done this  

 job properly (as I'm sure you have) so long as the webbing is  

 intact, the seat pan will not fail. So, my humble advice would be  

 to repair the cracks in the pan and carefully inspect pan, webbing  

 and its attachment points at each annual.



 Marco Menezes N99KX

 Model 2 582-90 C-Box 3:1 w/clutch

 --- On Mon, 12/22/08, sbennett3 <sbennett3(at)aol.com> wrote:

 From: sbennett3 <sbennett3(at)aol.com>

 Subject: Re: Kitfox III Fiberglass Seat Pan Cracking

 To: kitfox-list(at)matronics.com

 Date: Monday, December 22, 2008, 10:32 AM



 Ken, I don't have suggestions to help you fix your seat issue, just  

 a reminder that there are control rods running under that seat that  

 if collapsed on will keep you from being able to control ailerons.   

 I had that happen to me once. Maybe a new seat can be on your  

 Christmas list.  Personally, i'd replace it.  Steve Bennett   

 classic 4 912ul... Durham NC



 In a message dated 12/22/08 10:12:44 Eastern Standard Time,  

 kenharrison(at)comporium.net writes:

 What is the best way to keep the fiberglass seat from cracking?   

 Mine has very small cracks that are right at the outside edges both  

 sides, basically half way up the back.  It makes a crackling sound  

 every time I get in.  I have re-enforced the seat with some seat  

 belt material underneath but was wondering if anyone has a better  

 solution.



 I am going to repair the fiberglass and thought I’d check to see if  

 anyone has dealt with this problem.  I don’t want to make the  

 fiberglass repair and then just have it crack again in the same place.



 I’ve read about the seats failing and jamming the controls...always  

 in the back of my mind.



 Thanks,

 Ken



 Listen to 350+ music, sports, & news radio stations – including  

 songs for the holidays – FREE while you browse. Start Listening Now!

 blank rel=nofollow>http://www.matronics.com/ 

 contributionarget=_blank rel=nofollow>http://www.matronics.com/ 

 Navigator?Kitfox-List=nofollow>http://forums.matronics.com



 ============================================================ _- 

 ============================================================ _- 

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

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

lcfitt(at)sbcglobal.net
Guest

Posted: Mon Dec 22, 2008 11:02 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Ken,



My suggestion would be to scuff sand the cracked edge top and bottom and lay 

a couple of layers of fiberglass tape (top and bottom) over the surface near 

the edge.  The top (white) layer is gelcoat and make sure the scuff sanding 

removes the gelcoat in the affected areas. the edge would then be similar to 

a foam sandwich where the original glass and cracks would be like the foam 

and really non structural and the layers of glass top and bottom would be 

the structural part.  Also my opinion is that your repair would be for the 

most part to eliminate the noise and give some confidence that the seat will 

not crack straight across.  Fiber glass structures are not like plexiglass 

where a crack will always continue to propagate.  Consider also that seat 

lockers were common options for small tools etc.  These required cutting 

large holes in the seat bottoms which would seriously weaken the structure.



Regarding the seat pan failures in the past.  I don't think there has ever 

been a pan failure in a Model I through IV.  The failures came after Skystar 

added the trim panel in front of the seat and needed to change the leading 

edge of the seat from the tube grabbing "C" lip to the gentler curved and 

shorter 45° lip to accommodate the trim panel.  This is a classic example of 

how a seemingly non structural design change to add a bit of eye appeal (and 

weight) resulted in a serious safety issue.  The failures were not 

structural failures of the pan, but would come on a hard landing or severe 

turbulence when the seat would spring down under the pilot's weight and the 

forward lip would slip off the bulkhead tube.  I am not aware of a seat 

failure from structural collapse.  Also regarding the old style,  I know a 

guy that has put over a thousand hours on two Model IVs and has never tied 

the seat pan to the airframe with the nylon tiewraps.  I have seen him in 

"turn back" turbulance and tons of off airport landings with no incidences.



Lowell Fitt

Cameron Park, CA

Model IV-1200 R-912 UL

Currently focusing on the Left Wing - almost ready to cover, fuselage as 

well.



---

MichaelGibbs(at)cox.net
Guest

Posted: Mon Dec 22, 2008 12:32 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

Lynn sez:



 >Here's another idea....install under-seat tool boxes.

 >John & Debra McBean sell them I'm sure. Either

 >there or Murle Williams.



I can't say how they affect the structural integrity of the seat pan  

but during my accident both under-seat compartments in my 'fox were  

completely flattened.  We believe they helped cushion the impact by  

crumpling, though, and I had no back injuries.



I got my toolboxes from Murle Williams <http:// 

MurleWilliamsAviation.com>



Mike G.

Kitfox IV-1200 Speedster

Phoenix, AZ



 	  Quote: 	
		  >

>

>

>

Lynn Matteson

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

Posted: Mon Dec 22, 2008 1:09 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

They might just provide a "crush zone" in that regard. I think I got  

mine from Williams, too. As I recall, John either didn't have them  

when I ordered mine, or I didn't check....and this was before he  

became       www.kitfoxaircraft.com       anyway.

Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

Sensenich 62x46

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

system;

also building a new pair of snow skis

On Dec 22, 2008, at 3:23 PM, Michael Gibbs wrote:

 	  Quote: 	

 <MichaelGibbs(at)cox.net>

 Lynn sez:

 >Here's another idea....install under-seat tool boxes.

 >John & Debra McBean sell them I'm sure. Either

 >there or Murle Williams.

 I can't say how they affect the structural integrity of the seat  

 pan but during my accident both under-seat compartments in my 'fox  

 were completely flattened.  We believe they helped cushion the  

 impact by crumpling, though, and I had no back injuries.

 I got my toolboxes from Murle Williams <http:// 

 MurleWilliamsAviation.com>

 Mike G.

 Kitfox IV-1200 Speedster

 Phoenix, AZ

>>

>>

>>

>>

>>

>>

>>

>>

>>

>>

>>

>>

>>

>>

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Lynn Matteson

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

Posted: Mon Dec 22, 2008 1:16 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

When I bought my minimally completed kit, it came with a seat support  

kit, which consisted of  2" wide web strapping, and 8 hose clamps,  

and directions for slotting the seat so the clamps could be slid  

through the slots and around the fuselage tubes. I installed all 8 at  

first, then during the first annual, cut the number to 4. Big PITA to  

R & R them, and I feel 4 does the job WAY more than the tiewraps  

could ever hope to.



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

Sensenich 62x46

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

system;

also building a new pair of snow skis





On Dec 22, 2008, at 1:54 PM, Lowell Fitt wrote:



 	  Quote: 	
		   

 <lcfitt(at)sbcglobal.net>


	


 	  Quote: 	
		   I know a guy that has put over a thousand hours on two Model IVs  

 and has never tied the seat pan to the airframe with the nylon  

 tiewraps.  I have seen him in "turn back" turbulance and tons of  

 off airport landings with no incidences.



 Lowell Fitt

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

MDKitfox(at)AOL.COM
Guest

Posted: Mon Dec 22, 2008 1:31 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

Lynn,



When I installed my seat pan (at the very end of the build process) I had already installed four web straps to support the seat from 'falling' onto the controls.  (Each piece of webbing is good for supporting over a ton.)  I opted to use the tie wraps (instead of hose clamps) figuring they're there just to keep the seat pan from bouncing up and off the support tubes in case of turbulence.  I don't see that they don't provide any other obvious function.  Even wearing the seat belts provides substantial down force on the seat to hold it in place.  Am I missing something here about the hose clamps?



 Rick Weiss

N39RW Series V Speedster, 912ULS

SkyStar S/N 1

Port Orange, FL



 



On Dec 22, 2008, at 4:16 PM, Lynn Matteson wrote:

 	  Quote: 	
		  --> Kitfox-List message posted by: Lynn Matteson <lynnmatt(at)jps.net (lynnmatt(at)jps.net)>



When I bought my minimally completed kit, it came with a seat support kit, which consisted of  2" wide web strapping, and 8 hose clamps, and directions for slotting the seat so the clamps could be slid through the slots and around the fuselage tubes. I installed all 8 at first, then during the first annual, cut the number to 4. Big PITA to R & R them, and I feel 4 does the job WAY more than the tiewraps could ever hope to.



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

Sensenich 62x46

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

also building a new pair of snow skis





On Dec 22, 2008, at 1:54 PM, Lowell Fitt wrote:



 	  Quote: 	
		  --> Kitfox-List message posted by: "Lowell Fitt" <lcfitt(at)sbcglobal.net (lcfitt(at)sbcglobal.net)>

I know a guy that has put over a thousand hours on two Model IVs and has never tied the seat pan to the airframe with the nylon tiewraps.  I have seen him in "turn back" turbulance and tons of off airport landings with no incidences.



Lowell Fitt

	
http://www.matronics.com/contribup;            &n  --> http://forums.matroni===================





	


=  [quote][b]

Lynn Matteson

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

Posted: Mon Dec 22, 2008 1:47 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

I don't think you're missing a thing, Rick. In fact, I think I missed  

something when I installed them. I think the maker of that  

aftermarket kit went overboard when they decided on the hose  

clamps...and these are the 1/2" wide jobs to boot. I may just opt for  

the tiewraps in the future, or at the very most the narrower 1/4"  

size hose clamps.

My web straps are slotted so the hose clamps or tie wraps can go  

through them and help hold them in place.



I guess I should have said earlier that the "4 hose clamps are WAY  

more than *necessary* to do the job."



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

Sensenich 62x46

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

system;

also building a new pair of snow skis





On Dec 22, 2008, at 4:30 PM, Weiss Richard wrote:



 	  Quote: 	
		   Lynn,



 When I installed my seat pan (at the very end of the build process)  

 I had already installed four web straps to support the seat from  

 'falling' onto the controls.  (Each piece of webbing is good for  

 supporting over a ton.)  I opted to use the tie wraps (instead of  

 hose clamps) figuring they're there just to keep the seat pan from  

 bouncing up and off the support tubes in case of turbulence.  I  

 don't see that they don't provide any other obvious function.  Even  

 wearing the seat belts provides substantial down force on the seat  

 to hold it in place.  Am I missing something here about the hose  

 clamps?

 Rick Weiss

 N39RW Series V Speedster, 912ULS

 SkyStar S/N 1

 Port Orange, FL





 On Dec 22, 2008, at 4:16 PM, Lynn Matteson wrote:



> 

>

> When I bought my minimally completed kit, it came with a seat  

> support kit, which consisted of  2" wide web strapping, and 8 hose  

> clamps, and directions for slotting the seat so the clamps could  

> be slid through the slots and around the fuselage tubes. I  

> installed all 8 at first, then during the first annual, cut the  

> number to 4. Big PITA to R & R them, and I feel 4 does the job WAY  

> more than the tiewraps could ever hope to.

>

> Lynn Matteson

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Tom Jones

Joined: 12 Mar 2006
Posts: 752
Location: Ellensburg, WA

Posted: Mon Dec 22, 2008 3:30 pm Post subject: Re: Kitfox III Fiberglass Seat Pan Cracking

 	  Quote: 	
		  I am going to repair the fiberglass and thought Iâ€™d check to see if anyone has dealt with this problem. I donâ€™t want to make the fiberglass repair and then just have it crack again in the same place. 	




Ken, I broke my seat during the building.  I had the seat sitting in the fuselage and was in there doing something.  I put all my 160 pounds on one knee on the center ridge and it popped like a rifle shot.  It had a crack clear through about six inches long.  I fixed it by laminating a couple layers of fiberglass cloth on the underside.  I tested it with the knee treatment after it cured and have not had any more problems.  It's probably stronger that new.

_________________
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA

patreilly43(at)hotmail.co
Guest

Posted: Mon Dec 22, 2008 8:06 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

Lowell C My Mod 3 seat pan has holes in it and on the frame cross members that match up for rivets. You mention using tie wraps to attach pan to frame. Is that the normal method? I mounted my radiator with your shutters today after combining the parts you sent to me to modify the shutters to accomodate my taller radiator. Looks like they will work fine. I purchased the control cable you recommended. Any progress on the electric trim kit yet?

  

 Pat Reilly

 Mod 3 582 Rebuild

 Rocford C IL



[quote] From: lcfitt(at)sbcglobal.net

 To: kitfox-list(at)matronics.com

 Subject: Re: Kitfox III Fiberglass Seat Pan Cracking

 Date: Mon C 22 Dec 2008 10:54:32 -0800

 

 --> Kitfox-List message posted by: "Lowell Fitt" <lcfitt(at)sbcglobal.net>

 

 Ken C

 

 My suggestion would be to scuff sand the cracked edge top and bottom and lay 

 a couple of layers of fiberglass tape (top and bottom) over the surface near 

 the edge. The top (white) layer is gelcoat and make sure the scuff sanding 

 removes the gelcoat in the affected areas. the edge would then be similar to 

 a foam sandwich where the original glass and cracks would be like the foam 

 and really non structural and the layers of glass top and bottom would be 

 the structural part. Also my opinion is that your repair would be for the 

 most part to eliminate the noise and give some confidence that the seat will 

 not crack straight across. Fiber glass structures are not like plexiglass 

 where a crack will always continue to propagate. Consider also that seat 

 lockers were common options for small tools etc. These required cutting 

 large holes in the seat bottoms which would seriously weaken the structure.

 

 Regarding the seat pan failures in the past. I don't think there has ever 

 been a pan failure in a Model I through IV. The failures came after Skystar 

 added the trim panel in front of the seat and needed to change the leading 

 edge of the seat from the tube grabbing "C" lip to the gentler curved and 

 shorter 45° lip to accommodate the trim panel. This is a classic example of 

 how a seemingly non structural design change to add a bit of eye appeal (and 

 weight) resulted in a serious safety issue. The failures were not 

 structural failures of the pan C but would come on a hard landing or severe 

 turbulence when the seat would spring down under the pilot's weight and the 

 forward lip would slip off the bulkhead tube. I am not aware of a seat 

 failure from structural collapse. Also regarding the old style C I know a 

 guy that has put over a thousand hours on two Model IVs and has never tied 

 the seat pan to the airframe with the nylon tiewraps. I have seen him in 

 "turn back" turbulance and tons of off airport landings with no incidences.

 

 Lowell Fitt

 Cameron Park C CA

 Model IV-1200 R-912 UL

 Currently focusing on the Left Wing - almost ready to cover C fuselage as 

 well.

 

 ---

lcfitt(at)sbcglobal.net
Guest

Posted: Mon Dec 22, 2008 9:24 pm Post subject: Kitfox III Fiberglass Seat Pan Cracking

Yes, Pat, when I built my  1993 Model IV the standard installation for the 

seat pan was tiewraps.  As I recall I put them about every six inches.  I 

used the ones that are about 9 inches long.  I rechecked the manual and it 

calls for eight in front and nine across the back.  Keep in mind that the 

tiewraps, the manual calls the them zip ties, are to hold the pan down on 

the tubing supports.  The "C" shaped lips keet it off the controls.   I plan 

to use the same method on the IV I am building now.  I see no reason not to. 

As I mentioned, the failures were due to the pan slipping off the forward 

tube support due to a redesign of the forward pan lip.  Also the tiewraps 

are replaced every annual as the seat pan is removed to inspect linkages 

beneath it,  so no age issues there.



Regarding the elevator trim kit.  It is still on the back burner pending a 

completion of a current project.  I am within a week of finishing that - I 

think -   then I will get the tooling out and make up the kit parts and try 

to determine a cost.  Maybe the first week in January for the results.



Yes, retired folks no longer get weekends and holidays.  I will probably 

spend at least part of Christmas day in the hangar trying to burn some holes 

in some 4130 tubing or maybe if I am lucky, bending some aluminum into a 

trim tab.



Lowell



---

patreilly43(at)hotmail.co
Guest

Posted: Tue Dec 23, 2008 9:13 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

Lowell C I know what you mean. When someone asks if I am retired. I ask them what retired means. I work from the time my feet hit the floor in the morning until I go to bed at night. If they ask C "What do you do" the reply is C "Whatever Joyce tells me to do. Joyce works me like a mule. But C I am crazy not stupid." Like the old guy I met at the doctors office said C "I'm retired. I get up in the morning without a damn thing to do. And C by the time I go to bed at night C I'm only half done." There is a secret to leading a productive life.......PRODUCE..... something anything C just produce. I'll be trying to get out of the casket to build something C anything. Keep up the good work and designing KF options.

 do not archive

 Pat Reilly

 Mod 3 582 Rebuild

 Rockford C IL  



[quote] From: lcfitt(at)sbcglobal.net

 To: kitfox-list(at)matronics.com

 Subject: Re: Kitfox III Fiberglass Seat Pan Cracking

 Date: Mon C 22 Dec 2008 21:20:08 -0800

 

 --> Kitfox-List message posted by: "Lowell Fitt" <lcfitt(at)sbcglobal.net>

 

 Yes C Pat C when I built my 1993 Model IV the standard installation for the 

 seat pan was tiewraps. As I recall I put them about every six inches. I 

 used the ones that are about 9 inches long. I rechecked the manual and it 

 calls for eight in front and nine across the back. Keep in mind that the 

 tiewraps C the manual calls the them zip ties C are to hold the pan down on 

 the tubing supports. The "C" shaped lips keet it off the controls. I plan 

 to use the same method on the IV I am building now. I see no reason not to. 

 As I mentioned C the failures were due to the pan slipping off the forward 

 tube support due to a redesign of the forward pan lip. Also the tiewraps 

 are replaced every annual as the seat pan is removed to inspect linkages 

 beneath it C so no age issues there.

 

 Regarding the elevator trim kit. It is still on the back burner pending a 

 completion of a current project. I am within a week of finishing that - I 

 think - then I will get the tooling out and make up the kit parts and try 

 to determine a cost. Maybe the first week in January for the results.

 

 Yes C retired folks no longer get weekends and holidays. I will probably 

 spend at least part of Christmas day in the hangar trying to burn some holes 

 in some 4130 tubing or maybe if I am lucky C bending some aluminum into a 

 trim tab.

 

 Lowell

 

 ---

Lynn Matteson

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

Posted: Tue Dec 23, 2008 10:42 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

I figure I'll be in the casket thinking:  "Now what in hell prompted  

them to build this thing like they did? Damn, if only they had....."



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 596+ hrs

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 23, 2008, at 12:13 PM, patrick reilly wrote:

 	  Quote: 	
		    I'll be trying to get out of the casket to build something, anything.


	


 	  Quote: 	
		   do not archive

 Pat Reilly

 Mod 3 582 Rebuild

 Rockford, IL

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Ken Potter

Joined: 18 Aug 2007
Posts: 85
Location: Lanark, Ontario

Posted: Wed Dec 24, 2008 3:56 am Post subject: Re: Kitfox III Fiberglass Seat Pan Cracking

Like Pat's,  my model II has rivet holes.  I am just about at the point of installing the seat and wasn't comfortable with the rivets (not being able to easily remove the seat for inspection.  The hose clamp idea sounds like a good solution.

Cheers and Merry Christmas



Ken

_________________
Ken Potter
Model II, No. 483
Rotax 582, C-Box,
99% Complete
C-FJKP
Lanark, Ontario

peteohms

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

Posted: Wed Dec 24, 2008 7:03 am Post subject: Kitfox III Fiberglass Seat Pan Cracking

My Model III has sheet metal screws in the "rivet" holes.



Pete



--- On Wed, 12/24/08, Ken Potter <kjpotter(at)sympatico.ca> wrote:

[quote]From: Ken Potter <kjpotter(at)sympatico.ca>

Subject: Re: Kitfox III Fiberglass Seat Pan Cracking

To: kitfox-list(at)matronics.com

Date: Wednesday, December 24, 2008, 4:56 AM



[quote]--> Kitfox-List message posted by: "Ken Potter"

<kjpotter(at)sympatico.ca>



Like Pat's,  my model II has rivet holes.  I am just about at the point of

installing the seat and wasn't comfortable with the rivets (not being able

to easily remove the seat for inspection.  The hose clamp idea sounds like a

good solution.

Cheers and Merry [quote][b]

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

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