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lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Tue Mar 22, 2016 4:31 pm Post subject: Elevator/Stabilizer hinge ass'y

Bill, I am not interested in getting into a pissing match. Â 



Â You wrote-"This aircraft will be flying over a densely populated area. I believe the vast majority of Kolbs are not being flown over populated areas."

I am under the impression that you intended this for back country use. This is the first I have heard of heavily populated areas.

Even so, I don't see a problem either way. I flew a 503 to Demming NM and back to Oregon on a 503. The only problem I had was the amount of gas that it took. I have had one forced landing while flying a two stroke. I got into a situation that I needed to fly my plane after a long lay off, and before I had done an annual. I lost a spark plug cap on my way back home. I was flying a 447 at the time (single ignition) That was when I sprained my middle finger. Other than that I never had a problem. I am afraid that the reputation of the two strokes is for the most part put forth by the Spam can pilots who shudder at the thought of flying any thing uncertified much less one of our toys. Or people who are unable to maintain their engines as they should. What ever, it doesn't matter.

So far you have had good advice, that is one of the things that we on the list pride ourselves about. It is not apparent to me that you are accepting any of it. The Kolb with the proper engine is a fun reliable airplane even if built to standard plans. VG's help a lot, making it even safer and more fun to fly. Longer gear legs help as well. In my opinion the stock alum. legs is the only weak spot on the plane, but then again Homer intended it to be a weak spot so as to fail before the cage was damaged. In my case it appeared, at least to me, to cause more damage than it prevented, therefore the 4130 spring steel gear legs.Â 

If there is one thing that I have learned, its that it is by far the best to only do something once, and do it right Â the first time. I borrowed from my 401 K to buy an HKS. I then paid myself back with interest. I didn't buy it for the reliability, I bought it because a 503 would not get me to another airport without taking extra gas with me. It has been a bit of work, but it has been worth it. I do not intend to scrimp on my safety, for the sake of saving a few pennies. Of course I have been flying a Firestar for 19 years, so I am pretty happy with it.

There are a hell of a lot of very smart and handy guys on this list. I would hazard a guess that we have managed to screw up a few times and in the process learned a hell of a lot. All that experience is available to you, and almost all of us will make the effort to pass it on to you, If you appear to listen. Perhaps I am wrong, but I haven't noticed much listening on your part.

Â I would guess the closest thing to an engineer on this list would be Jack Hart. Personally from my experience that may be a good thing.Â 

You wrote- "Did me or anyone else tell you that you were stupid, at any time, inferred or expressed?"

Perhaps I am an overly sensitive person, but as they say "paranoia is merely an heightened sense of reality".

If you haven't done much to the Kit that you received, perhaps Kolb would consider taking it back. That is if you are not happy with it or think it is unsafe. If you do decide to keep it, make what ever changes you think best. It is "experimental" after all. You are free to make any changes you see fit.Â 

Now I don't know about you, but this is my last comment on the subject.

Respectfully,

Larry



-- 

The older I get, the less tolerant I am of those who are intolerant.





If you forward this email, or any part of it, please remove my email address before sending.

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victorbravo(at)sbcglobal.
Guest

Posted: Tue Mar 22, 2016 6:37 pm Post subject: Elevator/Stabilizer hinge ass'y

Guys, I cannot believe what has happened here. The moment I asked a couple of technical questions, and then explained my reasoning for simply asking the question, people panicked, got insulted, and painted me as the bad guy who's trashing a good airplane, or not wanting to hear what anyone else said, etc. A Heathen !!! 



I came to this list respectfully, asking for discussion and correspondence, and perhaps even friendly debate about this stuff, NEVER ONCE saying I was smarter than anyone, and NEVER ONCE saying I didn't want to hear about the experiences of more experienced Kolbers. I had/have all sorts of ideas about modifications, and adjustments, and upgrades and what not. I was just looking for a place to discuss them, de-bunk them, argue the pros and cons of any given idea, and brainstorm with like-minded Kolbers, etc.



The aircraft is indeed intended to be operated as a back country or off-airport fun machine, but I am still based at a city municipal airport that requires me to fly over solid city and houses to get into or out from that airport. So for at least the first and last 10 minutes of every flight, I need a high level of reliability. I also don't want to get stuck out in the middle of the desert either, even with no houses below me. There's !(#*% rattlesnakes out there. There is a good chance that my home airport won't even want me to fly this aircraft there if I used a 2 stroke.



Like I said, I will limit my future questions on this list to things that relate to the original Kolb plans and design. Any creative ideas, or new approaches, or innovtive thinking stuff... I'll have to go back and discuss that on HBA where people are not offended.



Bill Berle

www.ezflaphandle.comÂ  - safety & performance upgrade for light aircraft

www.grantstar.net Â  Â  Â  Â  Â  - winning proposals for non-profit and for-profit entities



--------------------------------------------

On Tue, 3/22/16, John Hauck <jhauck(at)elmore.rr.com> wrote:



 Subject: RE: Elevator/Stabilizer hinge ass'y

 To: kolb-list(at)matronics.com

 Date: Tuesday, March 22, 2016, 4:31 PM

 

 

 "John Hauck" <jhauck(at)elmore.rr.com>

 

 Bill B/Kolbers:

 

 I'll tell you if there was a cheap, reliable, alternate four

 stroke power plant for a Kolb aircraft, it would be flying

 on a lot of Kolbs and other makes of ULs and home builts.

 

 Sometimes one must pay for what he wants.Â  I

 have.Â  Haven't had an engine out in well over 3,000

 hours.Â  Did have a couple engine outs caused by bad

 fuel, but that was pilot error and had nothing to do with

 engine reliability. 

 

 Some of us have tried to share with you a little of our

 experience, but it seems you don't want to hear what we have

 to say.

 

 By now you should recognize there is no elevator hinge

 problem.Â  If you want to change yours when you get

 around to getting your hands dirty and actually building a

 Kolb, have at it.

 

 john h

 mkIII

 Fort Campbell, Kentucky

 

 

 

  

 

 --

Richard Pike

Joined: 09 Jan 2006
Posts: 1670
Location: Blountville, Tennessee

Posted: Tue Mar 22, 2016 7:52 pm Post subject: Re: Elevator/Stabilizer hinge ass'y

Bill - take a deep breath. Prop your feet up. Relax. Nobody is mad, it's just that you are amongst a bunch of old curmudgeons and we are doing what we do.   Having said that,  I noticed something in your last post that says volumes to me; "There is a good chance that my home airport won't even want me to fly this aircraft there if I used a 2 stroke."     OK.... I think I see the problem



I have a beloved daughter who is married to a nice guy who lives in LA. I raised that child right, she has her head on straight, but after several years of living in LA, she has adopted some really odd concepts, probably to get along with her fruits and nuts peer group. Peer pressure can be tough.



Brother Bill, I have said all that to say this: if you get a Kolb, you will be really out of the mainstream at a GA airport that expects you to be a conformist, and you have 2 options: try to conform to their expectations, stay frustrated, and look at your really neat little airplane like they do - with a critical and jaundiced eye - always looking for and finding something else to criticize. 

Or...

Stand up for yourself and your airplane and take no prisoners. I went out to the hangar today and looked at the tail and the elevator hinge. I looked at the rivits. I moved the elevator up and down, I  looked at the cables, I thought about it a bit. I decided that while I have a number of problems in my life, the tail of my Kolb ain't one of them.



When I transferred to TRI and started training here, my instructor Joe was half Indian, and had the worst temper of any man I ever knew. Ask any air traffic controller, they will tell you that some days are just "dummy days." Everybody on frequency is acting stupid. Joe had the solution to dummy days; he told me "Pick somebody at random and just chew his ass unmercifully: everybody else on frequency will smarten up."



Try that at your GA airport on anybody that finds fault with your airplane or engine and I suspect the rest of them will not say a peep regardless of what engine you use or what your airplane looks like. And you will be a lot happier, even if some people do think of you as an old curmudgeon.

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

johngilpin

Joined: 23 Mar 2011
Posts: 93
Location: 004

Posted: Wed Mar 23, 2016 1:47 am Post subject: Elevator/Stabilizer hinge ass'y

I'm impressed with the gentlemanly manner that this discussion has developed.Â  Good points, right to the point, without getting into personal flaming.Â  Much more decent than many other forums......

I put a couple of hundred hours on a FireFly and a FireStar, flying from more than a hundred airfields, so lots of folding and unfolding.Â  Love that Kolb tail folding mechanism, absolutely brilliant!Â  I'll be copying it on a homebuilt trailerable ultralight that I'm working on.Â  I have no worries about it's strength, considering the light loads involved, and history confirms that.

'nother topic -Â 

Sure would be good if replying posters would get into the habit of deleting the ever increasing trail of earlier poststhat follows each post and just gets longer and longer......Â  Not hard to do, just leave a pertinent line or two to specifically remind us what you are replying to.....



JG

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Wed Mar 23, 2016 6:45 am Post subject: Elevator/Stabilizer hinge ass'y

Hi,



Â  I have noticed that the messages keep getting stuck on the posts, but I was unsure if it was happening to all the emails, or just mine. Is it all emails from Kolb, or just mine. I am taking measures to stop mine, but quite frankly it is a pain in the butt.Â 

Thanks

Larry

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undoctor(at)rcn.com
Guest

Posted: Wed Mar 23, 2016 8:18 am Post subject: Elevator/Stabilizer hinge ass'y

Guilty, Larry. Thought of it after I hit send. Sorry. 

Dave Kulp

Do not archive

Sent from my Verizon Wireless 4G LTE smartphone



-------- Original message --------

From: Larry Cottrell  

Date:03/23/2016  10:44 AM  (GMT-05:00) 

To: kolb-list(at)matronics.com 

Subject: Re: Kolb-List: Re: Elevator/Stabilizer hinge ass'y 

Hi,



  I have noticed that the messages keep getting stuck on the posts, but I was

mojavjoe

Joined: 23 Dec 2013
Posts: 64

Posted: Wed Mar 23, 2016 9:38 am Post subject: Elevator/Stabilizer hinge ass'y

Aman Stuart you said it before I could!

From: "Stuart Harner" <stuart(at)harnerfarm.net>

To: "kolb-list" <kolb-list(at)matronics.com>

Sent: Tuesday, March 22, 2016 3:27:54 PM

Subject: RE: Elevator/Stabilizer hinge ass'y

--> Kolb-List message posted by: "Stuart Harner" <stuart(at)harnerfarm.net>

Bill,

I am not an engineer but I did stay in a Holiday Inn last night.   No, not really, but I do have a fundamental understanding of load transmission through a structure.

First a question, and please don't be offended.  Have you had an opportunity to observe the structure of the Kolb tail while it was being folded and then again when it is bolted into place?  I asked this because I found a couple of things in the plans of the Firefly that I did not understand until I was able to actually see it live. Simply put, I had trouble visualizing it from just the plans.

One thing that I think is missing from this discussion is the loads carried by the brace wires. I would posit that most of the forces from the tail that are transmitted to the boom tube are carried by the braces. These, when properly tensioned are actually pre-loaded slightly. This puts the tubes in compression which makes the whole thing quite strong. It also transfers the loads from the horizontals to the steel post of the verticals which in turn is transferred to the boom tube via the steel ring which is bolted and/or riveted to the tube.

Of course some loads are transferred through the hinge points and the front hinge must be able to slide slightly as the elevator moves through its arc of travel. Could this be made stronger? Of course, but not without sacrificing something else such as weight or foldability. It is actually a very clever design and I suspect that the majority of loads that move through the rear hinge come from the elevator and not the stabilizer. 

I would also bet that the loads carried through the hinges is far below the shear and tension limits of properly installed rivets.

I am actually more "freaked out" by the fact that everything in the tail depends on that one little 3/16" bolt (Firefly) that holds the lower braces in place. Really, the threads on that bolt are all there is between you and falling out of the sky. To combat this irrationality I swap out the bolt fairly often and the nuts even more often. If it really bothered me, I would stay on the ground. 

Perhaps you could send a copy of your plans to Barnaby Wainfan and ask for his analysis. I hear he is a really nice guy. From reading his articles over the years I am sure he could provide the answers you seek.

As Uncle Red used to say: "Remember, if women don't find you handsome, they should at least find you handy"

Stuart

--

victorbravo(at)sbcglobal.
Guest

Posted: Wed Mar 23, 2016 9:41 am Post subject: Elevator/Stabilizer hinge ass'y

On Tue, 3/22/16, John Hauck <jhauck(at)elmore.rr.com> wrote:



" I'll tell you if there was a cheap, reliable, alternate four  stroke power plant for a Kolb aircraft, it would be flying

 on a lot of Kolbs and other makes of ULs and home builts. "



That is exactly what Pegasus Air Power is working on with their O-100 engine. 58HP maximum and at least 50HP continuous, with "Continental aircraft engine" reliability, and 105 pounds ready to fly. Can use cheap used Continental cylinder assemblies to save money, or new ones for those who want new. I have seen this engine run, and I've seen the effort that is being put into the development. 

 

 " Some of us have tried to share with you a little of our  experience, but it seems you don't want to hear what we have  to say."



Nonsense. Y'all need to remember that there's supposed to be two sides of a discussion, not one. That's the difference between discussion/debate/brainstorming and a one-sided lecture or church sermon. 

 

 "By now you should recognize there is no elevator hinge  problem.Â  "



I recognized then, and now, that the loads on the rear of the stabilizer root are light on this aircraft, and that these loads are further reduced by the presence of the brace wires. Considering that the elevator pivot bolt is carried by a heavy steel ring, it is clear that the elevator pivot bolt, loaded properly in shear on both sides of the steel ring, is strong enough to carry the elevator loads and the rear stabilizer attach load. However, the load path between the elevator pivot bolt and the stabilizer root is compromised by a hinge mounting design that is questionable. 



So I have indeed come to the conclusion that the rear stabilizer root loads are low enough that they can be carried by the elevator pivot bolt, without a separate root attach fitting. This heated discussion served to get me fired up enough to look closely at it, and consider all options instead of just my first idea. So I have this list to thank for part of it. 



Now, as for the hinges themselves, one FINAL time... try to visualize this question:



1) Imagine the front door on your house. The hinges are flat piano hinges, and they're screwed on to the flat edge of the door and the flat edge of the door frame. 

2) Now imagine a chain link fence post and a chain link gate, which are made out of round poles that need to be hinged together. 



Question 1: Why are the gate hinges are not screwed right onto the tubes like they are on your front door?

Question 2: Why are the hinges for the round poles a different design than the flat hinges on your front door?



Bill

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Mar 23, 2016 10:28 am Post subject: Elevator/Stabilizer hinge ass'y

Question 1: Why are the gate hinges are not screwed right onto the tubes like they are on your front door?

Question 2: Why are the hinges for the round poles a different design than the flat hinges on your front door?



Bill

 



Bill B/Kolbers:



Never confronted a loose hinge on the elevator, but have experienced the bottom rudder hinge loosening rivets on my MKIII.  The reason is the extreme loads placed in the area of the rudder horn.  Not only is there pressure from the rudder cables one at a time, but there are times when rudder pedals are overloaded because of hard landings, crashes, or pure frightening occurrences.  It is normal to push on both pedals when experiencing these events.  That really loads up the bottom hinge on the rudder.



I have seen people bend the hinges to conform to the tube radius.  I am sure that made a stronger connection, but that amount of strength is not needed on the elevators.



john h

mkIII

Titus, Alabama

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

victorbravo(at)sbcglobal.
Guest

Posted: Wed Mar 23, 2016 10:39 am Post subject: Elevator/Stabilizer hinge ass'y

On Tue, 3/22/16, Stuart Harner <stuart(at)harnerfarm.net> wrote:



" One thing that I think is missing from this discussion is  the loads carried by the brace wires. "



Thank you Stuart, this is the missing piece that I did not pay enough attention to originally. 



I had been thinking of the stabilizer root as being much more movable than it actually is, because I was looking at the root attach fittings without the brace wires. If there is a brace wire from the fin post down to the rear stabilizer spar tube, then this wire will resist some of the up-down movement at the rear of the stabilizer root. As such, the reduction of vertical load/movement at this location reduces the load on the elevator pivot mechanism. I can now be a lot more confident in there being additional resistance to vertical movement of the rear stabilizer spar, and less need for a bolted fitting at that location.



Bill Berle

Eugene Zimmerman

Joined: 10 Jan 2006
Posts: 392

Posted: Wed Mar 23, 2016 6:04 pm Post subject: Elevator/Stabilizer hinge ass'y

 	  Quote: 	
		  On Mar 22, 2016, at 4:39 PM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:

Also, the hinges themselves are not designed for the loads to be hanging out 3/8 or 1/2 inch from their attachment, like a diving board.

	




Bill,



The surest way to compromise the structural integrity of a Kolb Aircraft is to attempt to fix a structual problem/weakness  that does not actually exist.



Over the years numerous kolb aircraft have experienced catastrophic violent crashes and not even in a violent crash has one ever documented a failure of the parts you hope to â€œimproveâ€.



[img]cid:EC5B878A-11DA-4A2E-ABDC-DAC2CFB95947(at)PK5001Z[/img]

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victorbravo(at)sbcglobal.
Guest

Posted: Wed Mar 23, 2016 6:29 pm Post subject: Elevator/Stabilizer hinge ass'y

Forget the !(#$(% hinges guys, like all of you have said over and over and over they don't fail. Congratulations, nobody has to think any more than that. This reminds me of the scene in the movie Rain Man where Tom Cruise finally says "That's all right Raymond, you don't have to answer any more questions."



Bill Berle

www.ezflaphandle.comÂ  - safety & performance upgrade for light aircraft

www.grantstar.net Â  Â  Â  Â  Â  - winning proposals for non-profit and for-profit entities

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Wed Mar 23, 2016 6:46 pm Post subject: Elevator/Stabilizer hinge ass'y

"This reminds me of the scene in the movie Rain Man where Tom Cruise finally says "That's all right Raymond, you don't have to answer any more questions."



Bill, does that mean we are all Savants? You certainly didn't say we were stupid,right?Â  ROFLMAO!



Larry

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rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Thu Mar 24, 2016 3:25 am Post subject: Elevator/Stabilizer hinge ass'y

Now that we've got that straight I'll try the engine again.

The HKS 700e is the reliable proven four stroke engine you seek.

Having said that, if you properly care for and feed a Rotax 503 equipped with an E or C gearbox, it'll be as reliable as any spam can engine out there. It'll just burn more gas than the HKS.



Dennis "Skid" Rowe



 	  Quote: 	
		   On Mar 23, 2016, at 10:29 PM, Bill Berle <victorbravo(at)sbcglobal.net> wrote:

 

 

 

 Forget the !(#$(% hinges guys, like all of you have said over and over and over they don't fail. Congratulations, nobody has to think any more than that. This reminds me of the scene in the movie Rain Man where Tom Cruise finally says "That's all right Raymond, you don't have to answer any more questions."

 

 Bill Berle

 www.ezflaphandle.com  - safety & performance upgrade for light aircraft

 www.grantstar.net           - winning proposals for non-profit and for-profit entities

Richard Pike

Joined: 09 Jan 2006
Posts: 1670
Location: Blountville, Tennessee

Posted: Thu Mar 24, 2016 5:05 am Post subject: Re: Elevator/Stabilizer hinge ass'y

If you don't like having all the hinges on one side, there is an easy fix: check out the picture of the elevator hinge below. 

Thanks to Eugene Zimmerman for the picture of N582EF in a wad. Kolb has come out with a new and much stronger axle fitting - shame that so many of them had to break first.

P1050018 (Medium).JPG

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_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

victorbravo(at)sbcglobal.
Guest

Posted: Thu Mar 24, 2016 9:05 am Post subject: Elevator/Stabilizer hinge ass'y

Thank you sincerely Richard, that hinge setup in your photo looks a lot more solid to me. If I were going to use the stock piano hinge I would do it that way (and feel much better about it than the original plans method). In fact, if there turns out to be some unforeseen problem with my own proposed hinge method, I will revert back to the method shown in your photo with piano hinges. At the very least it balances out the off-axis forces, which is what I was not happy with in the first place.



Bill Berle

www.ezflaphandle.comÂ  - safety & performance upgrade for light aircraft

www.grantstar.net Â  Â  Â  Â  Â  - winning proposals for non-profit and for-profit entities



--------------------------------------------

On Thu, 3/24/16, Richard Pike <thegreybaron(at)charter.net> wrote:



 Subject: Re: Elevator/Stabilizer hinge ass'y

 To: kolb-list(at)matronics.com

 Date: Thursday, March 24, 2016, 6:05 AM

 

 

 "Richard Pike" <thegreybaron(at)charter.net>

 

 If you don't like having all the hinges on one side, there

 is an easy fix:

 

 --------

 Richard Pike

 Kolb MKIII N420P (420ldPoops)

 Kingsport, TN 3TN0

 

 Would you consider yourself to be a good person?

 https://www.youtube.com/watch?v=VWcDXT6pH7A

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=454080#454080

 

 

 

 

 Attachments: 

 

 http://forums.matronics.com//files/p1050018_medium_336.jpg

 

 

 

 

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victorbravo(at)sbcglobal.
Guest

Posted: Thu Mar 24, 2016 10:15 am Post subject: Elevator/Stabilizer hinge ass'y

Thank you Dennis, after reading your comments about the HKS, I looked into it a little, and even found a video of a FireStar in Hawaii flying with the HKS. Can anyone here verify that an HKS 700E will deliver the same, more, or less thrust than a comparable "stock" 503 installation? Can anyone here verify from experience that the HKS has or does not have any specific issues, quirks, etc?



On Thu, 3/24/16, Dennis Rowe <rowedenny(at)windstream.net> wrote:



 Now that we've got that straight I'll try the engine again. The HKS 700e is the reliable proven four stroke engine you

 seek.

Richard Pike

Joined: 09 Jan 2006
Posts: 1670
Location: Blountville, Tennessee

Posted: Thu Mar 24, 2016 7:46 pm Post subject: Re: Elevator/Stabilizer hinge ass'y

As a retired pastor, one of the things that was supposed to be in my job description was that of being a peacemaker, and thinking about how this thread has gone, maybe there is time to still do that. Perhaps if - instead of focusing on the elevator hinge and associated mechanisms - which has had no known failures within the experience of this list - we had concerned ourselves with known problems and failures, our time might have been better spent.



So at the risk of hijacking the thread, I am going to do just that. I will probably not be able to remember all the Kolb things that have failed over the years, but I will enumerate all that I can, and if some of you can remember things that I can't, please add them in.



The forward attachment for the stabilizer: Somebody had one that did not make any provision to slide fore and aft as the elevator went up and down, and it bent the 2 stainless L brackets back and forth until they fractured. The front end of the stab popped up vertical, (!!!) but the pilot was able to maintain control and land safely.



The Firestar/Firestar II axle fitting. Originally designed for a Part 103 legal U/L, it was not changed and made it's way into heavier aircraft, where it was extremely marginal. Kolb now sells an upgrade. If you are flying any sort of non-103 FS/FSII - buy yourself a pair. Now.



Aileron Flutter. Kolb sells counterbalances. Get you some.



Rudder flutter. Some do, some don't. If you take your feet off the rudder pedals and they start to pulsate, be very careful. Either never take your feet off the rudder pedals, or make yourself a counterbalance. Something sort of like this: http://oh2fly.net/oldpoops/pg6.htm



Instability. Kolbs are unstable. You can add dihedral to a Firestar or Firestar II and they will become stable. The MKIII will not. Don't know about doing it to the Xtra, the Firefly or the Slingshot. Just so you know.



Full flaps on the MKIII with forward CG: If you have a heavy passenger and full flaps, you can run out of elevator authority in the flare, especially if you are slow and carrying any power. Gap sealing the elevator to the horizontal stab and adding VG's to the underside of the horizontal stab helps a lot.



Before we put the 582 on FSII N582EF, Kolb expressed concern that the upper fuselage structure was not designed for that much torque, and were concerned that at full throttle and encountering a big thermal might cause the upper rear spar structure to twist itself into really nasty shapes. If you are thinking of going big, beef up that area.



Front spar collapse: John Hauck posted some really freaky pictures of what happened to his front spar when the forward part of the ribs failed in compression, and brought him down under silk. Make sure that your leading edge cannot move or displace under any circumstances.



Twinstar MKII: I have seen one of them break the boom tube right at the end of the fuselage cage because the H insert was not properly installed. Inspect carefully.



MKIII spar bolt: A MKIII was lost w/fatality because the 1/2" bolt that goes through the main spar into the lift strut fitting was omitted, and the bracket was attached only by the pop rivets that held it in place prior to bolt insertion. 



Breakage of the lower vertical fin post: Racking the tail wheel around on rough ground puts huge side loads on the lower steel post of the vertical stabilizer, John Hauck broke his. It is wise to add braces from the lower part of that post to the steel ring that fits into the rear of the fuselage tube to strengthen it.



It's now 11:35, and that's all I can remember; I'm sure the rest of you guys can add to this list. Once the list becomes comprehensive, maybe it ought to be made into an unofficial AD Notice list and made into a sticky?

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Thu Mar 24, 2016 9:23 pm Post subject: Elevator/Stabilizer hinge ass'y

I do hope that you are right. Personally I came to the conclusion that if he looked in the mirror he would see the "bully" that he was describing. I guess he reminds me a bit too much of Jet Pilot. :-/ Â I guess I prefer do'ers rather than talkers. I probably spent too many years as a cop, and my belief in my fellow man was most likely stunted. 



I shall wait with interest, and hope for the best.

Larry

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victorbravo(at)sbcglobal.
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Posted: Thu Mar 24, 2016 11:36 pm Post subject: Elevator/Stabilizer hinge ass'y

Oh my goodness....

On Thu, 3/24/16, Larry Cottrell <lcottrell1020(at)gmail.com> wrote:

 

 I do hope that you are right. Personally I came to the conclusion that if he looked in the mirror he would see the "bully" that he was

 describing. I guess he reminds me a bit too much of Jet Pilot. :-/ Â I guess I prefer do'ers rather than talkers. I probably spent too many years as a cop, and my belief in my fellow man was most likely stunted.  I shall wait with interest, and hope for the best.Larry

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