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TR-1 Incident down under

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mark_trickel

Joined: 13 Dec 2011
Posts: 101
Location: Philadelphia, PA, USA

Posted: Wed Nov 26, 2014 6:38 am Post subject: TR-1 Incident down under

KIS Incident Down Under



With regret, I post this news from Australia - Michael Pattenâ€™s TR-1 main gear collapsed during roll out after touchdown when one of the attach bolts let lose:



Airframe event involving a Amateur Built Aircraft KIS TR-1, VH-AIG, Taree, Aerodrome, NSW on 9 September 1996.

Following an uneventful flight, the pilot reported that the aircraft touched down normally. After rolling about 80 m the right wing dropped and the pilot suspected a tire had failed. But about 50 m further on he heard pronounced scraping noises and the aircraft slewed right then left before finally coming to a halt about 10 m to the left of the runway. A subsequent inspection of the aircraft revealed that the fixed landing gear attachment bolts had failed at the countersunk heads. The failure faces contained rust deposits, indicating the bolts had been cracked for some time prior to the accident. The manufacturer has subsequently changed the design specification to fit standard flat head bolts in place of countersunk bolts.



The complete report is located here:

http://www.atsb.gov.au/publications/investigation_reports/1996/aair/199602857.aspx



I ran out to my hanger/shed, and checked mine (my TR-1C is a very early kit #23), it has the round Allen head bolts which are recessed into the attach bracket â€“ I will be checking them for any signs of corrosion or cracking, and I recommend you check yours too. Can anybody confirm that there was a change to a counter sunk flat head bolt???  Galin â€“ while you are down for repairs you may want to consider replacing these main gear bolts.



Mark T.

bakerocb

Joined: 15 Jan 2006
Posts: 727
Location: FAIRFAX VA

Posted: Wed Nov 26, 2014 8:03 am Post subject: TR-1 Incident down under

11/26/2014



Hello Mark, I am sorry to hear of the KIS Incident Down Under. You wrote: 

"Can anybody confirm that there was a change to a counter sunk flat head 

bolt???"



Here is my perception / recollection of the landing gear retention bracket 

situation:



1) The one piece aluminum main landing gear on the tricycle gear KIS TR-1 

had a rectangular cross section and the center portion of the gear was 

fastened into a recess in the bottom of the composite fuselage.



2) The gear was held up into place in the composite recess by two metal 

brackets each of which had two bolts, one bolt forward of the cross section 

and one bolt aft of the cross section.



3) The earlier kit's brackets were an aluminum bar and were notched on the 

upper side to fit the rectangular cross section of the landing gear. These 

aluminum brackets were also counter sunk or recessed around the bolt holes 

in the bottom surface of the brackets so that either the head or threaded 

end of the bolt (depending upon direction of bolt insertion) did not have to 

project out into the air flow.



4) By the time my kit (#116) was made, the notched and recessed aluminum 

brackets were no longer being provided. Instead two pieces of flat, 

undrilled steel bar stock about 6 inches long, 1 inch wide, and 3/8 inch 

thick were provided as landing gear retention brackets. (Don't hold me to 

those exact dimensions -- I am not at the hangar and unable to measure.)



5) Since the flat steel bar stock was neither notched nor drilled the 

builder had to drill holes in the bar stock such that the sides  of the 

bolts would keep the gear center cross section from shifting fore and aft.



6) Normal steel AN bolts were provided to hold the steel brackets in place 

and either the head or threaded end of the bolt (depending upon direction of 

insertion) was left to stick out into the airflow past the bottom surface of 

the steel bracket.



Any questions?



OC



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



From: mark_trickel

Sent: Wednesday, November 26, 2014 9:38 AM

To: kis-list(at)matronics.com

Subject: TR-1 Incident down under






KIS Incident Down Under



With regret, I post this news from Australia - Michael PattenÃ¢â‚¬â„¢s TR-1 main 

gear collapsed during roll out after touchdown when one of the attach bolts 

let lose:



Airframe event involving a Amateur Built Aircraft KIS TR-1, VH-AIG, Taree, 

Aerodrome, NSW on 9 September 1996.

Following an uneventful flight, the pilot reported that the aircraft touched 

down normally. After rolling about 80 m the right wing dropped and the pilot 

suspected a tire had failed. But about 50 m further on he heard pronounced 

scraping noises and the aircraft slewed right then left before finally 

coming to a halt about 10 m to the left of the runway. A subsequent 

inspection of the aircraft revealed that the fixed landing gear attachment 

bolts had failed at the countersunk heads. The failure faces contained rust 

deposits, indicating the bolts had been cracked for some time prior to the 

accident. The manufacturer has subsequently changed the design specification 

to fit standard flat head bolts in place of countersunk bolts.



The complete report is located here:

http://www.atsb.gov.au/publications/investigation_reports/1996/aair/199602857.aspx



I ran out to my hanger/shed, and checked mine (my TR-1C is a very early kit 

#23), it has the round Allen head bolts which are recessed into the attach 

bracket Ã¢â‚¬â€œ I will be checking them for any signs of corrosion or cracking, 

and I recommend you check yours too. Can anybody confirm that there was a 

change to a counter sunk flat head bolt???  Galin Ã¢â‚¬â€œ while you are down for 

repairs you may want to consider replacing these main gear bolts.



Mark T.

Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=434702#434702

Keith.Miller(at)esa.int
Guest

Posted: Wed Nov 26, 2014 8:10 am Post subject: TR-1 Incident down under

when did "The manufacturer has subsequently changed the design specification

to fit standard flat head bolts in place of countersunk bolts."take place . i

still have the countersunk bolts !!!!.





From:	"mark_trickel" <marktrickel(at)gmail.com>

To:	kis-list(at)matronics.com,

Date:	11/26/2014 03:40 PM

Subject:	TR-1 Incident down under

Sent by:	owner-kis-list-server(at)matronics.com






KIS Incident Down Under



With regret, I post this news from Australia - Michael PattenÃ¢â‚¬â„¢s TR-1 main

gear collapsed during roll out after touchdown when one of the attach bolts

let lose:



Airframe event involving a Amateur Built Aircraft KIS TR-1, VH-AIG, Taree,

Aerodrome, NSW on 9 September 1996.

Following an uneventful flight, the pilot reported that the aircraft touched

down normally. After rolling about 80 m the right wing dropped and the pilot

suspected a tire had failed. But about 50 m further on he heard pronounced

scraping noises and the aircraft slewed right then left before finally coming

to a halt about 10 m to the left of the runway. A subsequent inspection of

the aircraft revealed that the fixed landing gear attachment bolts had failed

at the countersunk heads. The failure faces contained rust deposits,

indicating the bolts had been cracked for some time prior to the accident.

The manufacturer has subsequently changed the design specification to fit

standard flat head bolts in place of countersunk bolts.



The complete report is located here:

http://www.atsb.gov.au/publications/investigation_reports/1996/aair/199602857.aspx

I ran out to my hanger/shed, and checked mine (my TR-1C is a very early kit

#23), it has the round Allen head bolts which are recessed into the attach

bracket Ã¢â‚¬â€œ I will be checking them for any signs of corrosion or cracking,

and I recommend you check yours too. Can anybody confirm that there was a

change to a counter sunk flat head bolt???  Galin Ã¢â‚¬â€œ while you are down for

repairs you may want to consider replacing these main gear bolts.



Mark T.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=434702#434702



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galinhdz(at)gmail.com
Guest

Posted: Wed Nov 26, 2014 9:04 am Post subject: TR-1 Incident down under

Last year (2013) I actually replaced these bolts and the rubber "gaskets" they hadÂ even though they looked good withÂ no sign of fatigue.



On Wed, Nov 26, 2014 at 9:38 AM, mark_trickel <marktrickel(at)gmail.com (marktrickel(at)gmail.com)> wrote:

[quote]--> KIS-List message posted by: "mark_trickel" <marktrickel(at)gmail.com (marktrickel(at)gmail.com)>

 

 KIS Incident Down Under

 

 With regret, I post this news from Australia - Michael Pattenâ€™s TR-1 main gear collapsed during roll out after touchdown when one of the attach bolts let lose:

 

 Airframe event involving a Amateur Built Aircraft KIS TR-1, VH-AIG, Taree, Aerodrome, NSW on 9 September 1996.

 Following an uneventful flight, the pilot reported that the aircraft touched down normally. After rolling about 80 m the right wing dropped and the pilot suspected a tire had failed. But about 50 m further on he heard pronounced scraping noises and the aircraft slewed right then left before finally coming to a halt about 10 m to the left of the runway. A subsequent inspection of the aircraft revealed that the fixed landing gear attachment bolts had failed at the countersunk heads. The failure faces contained rust deposits, indicating the bolts had been cracked for some time prior to the accident. The manufacturer has subsequently changed the design specification to fit standard flat head bolts in place of countersunk bolts.

 

 The complete report is located here:

 http://www.atsb.gov.au/publications/investigation_reports/1996/aair/199602857.aspx

 

 I ran out to my hanger/shed, and checked mine (my TR-1C is a very early kit #23), it has the round Allen head bolts which are recessed into the attach bracket â€“ I will be checking them for any signs of corrosion or cracking, and I recommend you check yours too. Can anybody confirm that there was a change to a counter sunk flat head bolt???Â  Galin â€“ while you are down for repairs you may want to consider replacing these main gear bolts.

 

 Mark T.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=434702#434702

 

 

 

 

 

 

 

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sstearns2(at)yahoo.com
Guest

Posted: Thu Nov 27, 2014 12:01 pm Post subject: TR-1 Incident down under

I would recommend updating the gear installation using these gear blocks.   The blocks allow the gear to flex without affecting the bolts and they allow the bolts to be properly preloaded.



http://www.groveaircraft.com/radiusplates.html



Scott



 	  Quote: 	
		   On Nov 26, 2014, at 6:38 AM, "mark_trickel" <marktrickel(at)gmail.com> wrote:

 

 

 

 KIS Incident Down Under

 

 With regret, I post this news from Australia - Michael Pattenâ€™s TR-1 main gear collapsed during roll out after touchdown when one of the attach bolts let lose:

 

 Airframe event involving a Amateur Built Aircraft KIS TR-1, VH-AIG, Taree, Aerodrome, NSW on 9 September 1996.

 Following an uneventful flight, the pilot reported that the aircraft touched down normally. After rolling about 80 m the right wing dropped and the pilot suspected a tire had failed. But about 50 m further on he heard pronounced scraping noises and the aircraft slewed right then left before finally coming to a halt about 10 m to the left of the runway. A subsequent inspection of the aircraft revealed that the fixed landing gear attachment bolts had failed at the countersunk heads. The failure faces contained rust deposits, indicating the bolts had been cracked for some time prior to the accident. The manufacturer has subsequently changed the design specification to fit standard flat head bolts in place of countersunk bolts.

 

 The complete report is located here:

 http://www.atsb.gov.au/publications/investigation_reports/1996/aair/199602857.aspx

 

 I ran out to my hanger/shed, and checked mine (my TR-1C is a very early kit #23), it has the round Allen head bolts which are recessed into the attach bracket â€“ I will be checking them for any signs of corrosion or cracking, and I recommend you check yours too. Can anybody confirm that there was a change to a counter sunk flat head bolt???  Galin â€“ while you are down for repairs you may want to consider replacing these main gear bolts.

 

 Mark T.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=434702#434702

mjpienaar(at)shaw.ca
Guest

Posted: Mon Dec 08, 2014 4:50 pm Post subject: TR-1 Incident down under

Hi Scott



Would you recommend these gear installation blocks for the TR4 as well?



Thanks



Mike

---

mikepapa(at)bigpond.com
Guest

Posted: Tue Dec 09, 2014 2:37 am Post subject: TR-1 Incident down under

Hi,

Just to clarify . This happened before my ownership, which I was aware of, and is in the log books. The damage was repaired well and the aircraft has flown 1000 hrs trouble free since. The current landing gear retaining brackets are pieces of flat bar, approx. 0.25in thick, with normal hex bolts. I believe they could be a little bit heavier, but they obviously work ok., as it has been into some  ordinary strips.



Regards,

Mike.



--

ftyoder(at)yoderbuilt.com
Guest

Posted: Tue Dec 09, 2014 4:45 am Post subject: TR-1 Incident down under

My kit #47 came with AN bolts but the manual shows the countersunk screws.



Tim 



--

sstearns2(at)yahoo.com
Guest

Posted: Sun Dec 14, 2014 4:21 pm Post subject: TR-1 Incident down under

Yes, but grove does not make a 1.25" version so you would have to make a 0.25" spacer.

Scott

        From: Mike Pienaar <mjpienaar(at)shaw.ca>

 To: kis-list(at)matronics.com 

 Sent: Monday, December 8, 2014 4:49 PM

 Subject: Re: TR-1 Incident down under

--> KIS-List message posted by: "Mike Pienaar" <mjpienaar(at)shaw.ca (mjpienaar(at)shaw.ca)>

Hi Scott

Would you recommend these gear installation blocks for the TR4 as well?

Thanks

Mike

---

mjpienaar(at)shaw.ca
Guest

Posted: Mon Dec 15, 2014 9:08 am Post subject: TR-1 Incident down under

Thanks Scott, 

  

 What do you mean by "they allow the bolts to be  properly preloaded"

  

 Thanks for your help

  

 Mike

  

  

 



  

 [quote]   ---

sstearns2(at)yahoo.com
Guest

Posted: Mon Dec 15, 2014 1:04 pm Post subject: TR-1 Incident down under

Hi Mike,



The proper use of a bolt is to clamp parts directly together.  Preloading a bolt is what we really do when we tighten a nut down to a certain torque value.  The bolt stretches as you tighten the nut and the bolt provides a constant clamping force (preload) as long the load on the joint never exceeds the clamping force provided by preloaded bolt.   



A great example is the bolts that clamp the main rod bearings around the crankshaft of an engine.  Lycoming is very specific on the procedure for torquing these bolts right down to specifying a specific thread lubrication fluid.  You can imagine if half the nut torque is going into moving a burr through the threads and not into stretching the bolt then you will not get the correct bolt preload.   In this case the joint will not be clamped together with a load greater than the load from moving the piston and the joint will open slightly and stretch the bolt with each load application. Now the load on the bolt is cycling instead of the bolt being under a constant preload keeping the joint clamped together.  Eventually the bolt will fatigue and fail.  As I recall this is what happened to the 400 hour since factory new engine in the original factory demo Cruiser leading to an off field landing.  

The landing gear bolts of course do not go through anywhere near the load cycles that the main bearing bolts do, but it is still good engineering to have bolted joints under a constant preload rather than cycling with every load cycle.  This requires a continuous joint and not leaving any part of the bolt in the open air as in the factory landing gear installation.

Here is a picture of my landing gear installation on my TR-1.  The bolts clamp the steel plate onto the flox pads and allow the bolts to be under a constant preload.  The grove parts are a better option today though since they have a built in radius that allows the gear to flex so you don't need the rubber pad.   The rubber pad goes around the landing gear and not under the bolts.  

http://www.kisbuild.r-a-reed-assoc.com/KIS-TR1-Web/ScottSterns/landinggear1.JPG



 

 



 

 

 

 

 

[/url]

[url=http://www.kisbuild.r-a-reed-assoc.com/KIS-TR1-Web/ScottSterns/landinggear1.JPG]View on www.kisbuild.r-a-reed...

Preview by Yahoo



 



  

Anyhow, this was probably more than you were asking for, but I hope it helps.

Cheers,

Scott

     

   From: Mike Pienaar <mjpienaar(at)shaw.ca> To: kis-list(at)matronics.com  Sent: Sunday, December 14, 2014 5:54 PM Subject: Re: TR-1 Incident down under  



          Thanks Scott, 

  

 What do you mean by "they allow the bolts to be  properly preloaded"

  

 Thanks for your help

  

 Mike

  

  

 

  

 [quote]   ---

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