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Check your Landing Gear Retraction Lever Strut (Mod 51)

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klaus.dietrich(at)oracle.
Guest

Posted: Tue Jul 13, 2010 9:41 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Check your Landing Gear Retraction Lever Strut (Mod 51)

 

 after 10 years in service and some 800 hours with as many landings, my Landing Gear Retraction Lever Strut (Mod 51) had an oval oversize hole at the bottom end (14mm; for the MS 20392-5C37 bolt which is 9,5 mm) and it finally broke at the top (just below the AN 3 bolt probably due to some misalignment due to the play at the bottom...

 no play at the top AN 3 bolt, however!

 

 The three screws on the Landing Gear Retraction Lever at the top seem to hold (no play)....

 

 I'm still searching for an explanation; my aluminum angle was probably not strong enough: material thickness: 1,5 mm; L-profile: 20 mm x 8 mm

 also the strut is not absolutely straight and there is some sideways flexibility which may have favored the play...

 

 Klaus

  	  Quote: 	
		  

	
 

 

  

    [quote][b]

davidjoyce(at)doctors.org
Guest

Posted: Tue Jul 13, 2010 1:53 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Klaus, Mine has gone exactly the same way. I  have removed it and am relying 

on the original three bolt joint with the two levers also bonded together. I 

am also avoiding trailing the plane with the wheel locked in the up 

position. Seems fine! Regards, David Joyce, G-XSDJ

---

budyerly(at)msn.com
Guest

Posted: Tue Jul 13, 2010 4:23 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Klaus and others, 

 Please send me pictures of your elongations or failures of the strut for me  to analyze.  If you can provide the type material and thickness also.

 Normally 6061 common aluminum angle of 1.6 mm or 1/16 inch is plenty  strong enough.

 Elongation of the hole at the bottom indicates slight movement of the gear  lock ,retraction mechanism (most probably in the down position) due to  not staying perfectly vertical with the gear down and eventually the  stresses from bending, as Klaus said, or from the latch slot gear retraction arm  interface bending, and or the three bolts elongation has  caused fatigue of the material or too much force on the aluminum angle  strut.  

  

 We will need some look see time to evaluate should if we go to steel or a  specific material/dimensions, time change, or what.

  

 In the mean time, if everyone can look at their Mod 51 landing gear  retraction lever strut brace if over say 500 hours and look for wear, as soon as  you can, and low time planes on your next annual, then send me updates, I'd  appreciate it.

  

  

 Many thanks,

  

 Bud Yerly,

 Europa Tech Assistance.

 direct email:  budyerly(at)msn.com (budyerly(at)msn.com)

 or just hold control key and click below to email

 via Europa website:  mailto:enquiries(at)europa-aircraft.com (enquiries(at)europa-aircraft.com)

 via Custom Flight Creations website: mailto:mail(at)customflightcreations.com (mail(at)customflightcreations.com)

  

  

 ---

rehn(at)rockisland.com
Guest

Posted: Tue Jul 13, 2010 5:20 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Bud   

I have not installed Mod 51 and have been flying with lots of landings for 10 years, am I living dangerously? I check the gear and don’t see issues but am I missing something? Am I the only one with out Mod 51?  

Jerry  

Mono 914  

         

  

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Bud Yerly

 Sent: Tuesday, July 13, 2010 5:17 PM

 To: europa-list(at)matronics.com

 Subject: Re: Check your Landing Gear Retraction Lever Strut (Mod 51)  

  

       

Klaus and others,   

    

Please send me pictures of your elongations or failures of the strut for me to analyze.  If you can provide the type material and thickness also.  

    

Normally 6061 common aluminum angle of 1.6 mm or 1/16 inch is plenty strong enough.  

    

Elongation of the hole at the bottom indicates slight movement of the gear lock ,retraction mechanism (most probably in the down position) due to not staying perfectly vertical with the gear down and eventually the stresses from bending, as Klaus said, or from the latch slot gear retraction arm interface bending, and or the three bolts elongation has caused fatigue of the material or too much force on the aluminum angle strut.    

    

   

    

We will need some look see time to evaluate should if we go to steel or a specific material/dimensions, time change, or what.  

    

   

    

[b]In the mean time, if everyone can look at their Mod 51 landing gear retraction lever strut brace if over say 500 hours and look for wear, as soon as you can, and low time planes on your next annual, then send me updates, I'd appreciate it.[/b]  

    

   

    

   

    

Many thanks,  

    

   

    

Bud Yerly,  

    

Europa Tech Assistance.  

    

direct email:  budyerly(at)msn.com (budyerly(at)msn.com)  

    

or just hold control key and click below to email  

    

via Europa website:  mailto:enquiries(at)europa-aircraft.com (enquiries(at)europa-aircraft.com)  

    

via Custom Flight Creations website: mailto:mail(at)customflightcreations.com (mail(at)customflightcreations.com)  

    

   

    

   

    

---

Roger.Mills(at)btinternet
Guest

Posted: Wed Jul 14, 2010 2:38 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

In my experience the danger is when you trailer the aircraft on a belly dolly with the Monowheel locked in the retracted position (although flying through prolonged choppy turbulence at 120kt might not be far behind?). The forces applied by the heavy weight of the wheel/tyre and long moment of the undercarriage arm when driving over potholes and other road surface problems are significant. Before fitting the strut I experienced significant distortion and elongation of the three holes through using a trailer with the wheel fully retracted just once and had to fabricate a new landing gear lever.   

   

I hoped the strut would fix the weakness but it’s conceivable that the forces involved in rough/turbulent air flight might elongate the bottom hole - will have to disassemble and examine now.  

   

Roger Mills  

G-BVUV  

   

   

   

   

   

       [quote][b]

davidjoyce(at)doctors.org
Guest

Posted: Thu Jul 15, 2010 1:49 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

I a sure Roger is right, and that is why I leave the wheel down when 

trailering on a dolly. However I first had trouble when flying though some 

severe turbulence in rotor in fairly high wind conditions in Welsh 

mountains. I only discovered the problem when I came to put the gear down 

and found that the joint had moved so that the gear lever stopped something 

like a cm short of its 'Down' detent. The problem was solved by pulling very 

hard on the lever and then giving my right fist a mighty thump with the 

other one. Since then I disassembled the joint, packed it with blue sticky 

mixture and reassembled it with mod 51. I have had no problem since in spite 

of lots of turbulence and knowing that mod 51 was shot & useless for some 

years. Regards, David Joyce, G-XSDJ

---

nigel_graham(at)m-tecque.
Guest

Posted: Thu Jul 15, 2010 3:00 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Gents,

  

 This problem was identified a long time ago (1999) and one  enterprising Scandinavian builder came up with an elegant and well engineered  solution (stand up and take a bow - Jens).

 Pictures below FYI.

  

 Nigel

  

 [img]cid:8600810E0D8C4FA1B4390566FD2283FD(at)hurricane[/img][img]cid:AAF62BA6396743B1A7A19B25D929BDD3(at)hurricane[/img]

 [quote]   ---

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fklein(at)orcasonline.com
Guest

Posted: Thu Jul 15, 2010 5:59 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

On Jul 15, 2010, at 2:47 AM, David Joyce wrote:



 	  Quote: 	
		   knowing that mod 51 was shot & useless for some years. Regards,  

 David Joyce, G-XSDJ


	


David,



..t'would be enlightening to me if you could elaborate a bit on what  

led you to this conclusion...



Fred

davidjoyce(at)doctors.org
Guest

Posted: Thu Jul 15, 2010 6:44 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Fred I haven't got a picture to hand, but the bottom bit of the additional 

strut is bent and the  hole in the bottom is worn to a bigger diameter. 

David

---

budyerly(at)msn.com
Guest

Posted: Thu Jul 15, 2010 4:28 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Jerry,

 You are not alone and not living dangerously, as it seems you have a well  built reliable gear.  However the non mandatory mod 51 arm helps keep the  stress down on the three bolts in the retraction arm.  Eventually, through  trailering, rough air, rough airstrips and countless landings you may  experience trouble.  If the arm flexes at the connection to the  LG08 it may be difficult to lower the gear and it may require you to unload  the aircraft to near negative G to flop the gear handle out of the slot.   On takeoff, you may find that the gear will not lock up  properly.  Extending the gear may leave the LG08 mechanism at less than  vertical.  Looseness at this joint will progress rapidly through  normal use as the gear has no over center lock per say and will bend at its  pivot points slightly both up and down, exacerbating the problem.  

  

 Even with mod 51, if the gear is not perfectly vertical from LG8 down, the  gear handle takes the load.  That dog leg in the gear handle with the bends  will flex over time, causing a higher than anticipated tension load on the Mod  51 diagonal brace.  We'll have a material and proper dimensions to use for  the arm soon.  We all used Home Depot aluminum on previous builds and I  should have questioned it, but I fly a trigear and rarely get a monowheel of  significant age in the shop.  No one reported the problem so it was unknown  to me until now.

  

 I would recommend one look at his retractable gear carefully on his  annual, and at 5 years or 500 landings do a full inspection and  rebuild.  Call me conservative in a liberal world, but the bushings and  landing gear block take a beating and are never cared for (I hate that dirty  hole..).  All the retractable gear certified planes I have experience with  require not just a retraction check but a complete check of the bearings and  bushings annually, slop and play are defined in the maintenance manual for the  aircraft.  Why shouldn't we do the same thorough inspections and replace  known wear points at a specific time to preclude future problems.

  

 Klaus and I discussed time changing out the following:

 At 5 years or 500 landings,

 Replace the bungee.

 Wheel bearings KLNJ 1 1/2   They are sealed bearings, and I  haven't seen a failure but why wait until they break.

 Brake pads (inspect caliper for corrosion) 

 Upper and lower bushings AIC 060816/AIC 060820. Inspect annually for play  and replace if detected and replace at 5 years anyway.

 Inspect Mod 51 arm for wear and replace as necessary

Inspect shock  absorbers and rubber block.  If it hops like a bunny, change the shocks, if  it sits low, change the block.  I don't know how low, low is, but the block  is about 70mm on an empty mono, so if it has lost 10 mm in height since new, it  probably needs replacing.

 Look at the long bolts Euro 26 and pins LG 04 for deformation, replace  as necessary

 Change the outrigger legs, inspect the pivot points and the locking  mechanism for corrosion and wear.  Remove and replace as necessary.

 Replace the outrigger tires/wheels if worn.

  

 I do not have a checklist for how I check the mono gear for play, and  frankly just look at the mechanics as I do not own one...  I support the  aircraft, push on the lower arm and watch the mechanism when down, especially  the locking arm.  Look at the LG 04 pin and support for cracks and  wear.  Any deformations of the gear requires replacement.  Then  partially retract the gear and check for play in the joints, wiggle the arms to  check for play, and pivot points for play (nasty dirty job), and finally  lock the gear up and check movement of the gear mechanism by pushing up on  the gear and using my bore scope to see if there are problems.  I have  never removed the mod 51, but I have also never worked on a high time  mono.  As for the outriggers, I have to look at the book if I have to take  one apart just to figure how to put it back together.  I make sure  that the gear leg locks down and that the flap moves through the proper number  of degrees before unlock.  I was not familiar with the Europa  Club bushing mod many of you had on the outriggers until Jim Butcher led me  through one.  I have only seen the standard factory build.  If there  is a comprehensive checklist other than the FAA condition inspection, I'd like  to see one for my own education.

  

 Sorry to be so long winded.

  

 Bud Yerly

 [quote]   ---

rehn(at)rockisland.com
Guest

Posted: Thu Jul 15, 2010 5:21 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Bud

Wow, thanks for a very thorough answer, I have a longer list for my next inspection.

Jerry



Sent from Iphone



On Jul 15, 2010, at 5:26 PM, "Bud Yerly" <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:



[quote] <?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  Jerry,

 You are not alone and not living dangerously, as it seems you have a well  built reliable gear.  However the non mandatory mod 51 arm helps keep the  stress down on the three bolts in the retraction arm.  Eventually, through  trailering, rough air, rough airstrips and countless landings you may  experience trouble.  If the arm flexes at the connection to the  LG08 it may be difficult to lower the gear and it may require you to unload  the aircraft to near negative G to flop the gear handle out of the slot.   On takeoff, you may find that the gear will not lock up  properly.  Extending the gear may leave the LG08 mechanism at less than  vertical.  Looseness at this joint will progress rapidly through  normal use as the gear has no over center lock per say and will bend at its  pivot points slightly both up and down, exacerbating the problem.  

  

 Even with mod 51, if the gear is not perfectly vertical from LG8 down, the  gear handle takes the load.  That dog leg in the gear handle with the bends  will flex over time, causing a higher than anticipated tension load on the Mod  51 diagonal brace.  We'll have a material and proper dimensions to use for  the arm soon.  We all used Home Depot aluminum on previous builds and I  should have questioned it, but I fly a trigear and rarely get a monowheel of  significant age in the shop.  No one reported the problem so it was unknown  to me until now.

  

 I would recommend one look at his retractable gear carefully on his  annual, and at 5 years or 500 landings do a full inspection and  rebuild.  Call me conservative in a liberal world, but the bushings and  landing gear block take a beating and are never cared for (I hate that dirty  hole..).  All the retractable gear certified planes I have experience with  require not just a retraction check but a complete check of the bearings and  bushings annually, slop and play are defined in the maintenance manual for the  aircraft.  Why shouldn't we do the same thorough inspections and replace  known wear points at a specific time to preclude future problems.

  

 Klaus and I discussed time changing out the following:

 At 5 years or 500 landings,

 Replace the bungee.

 Wheel bearings KLNJ 1 1/2   They are sealed bearings, and I  haven't seen a failure but why wait until they break.

 Brake pads (inspect caliper for corrosion) 

 Upper and lower bushings AIC 060816/AIC 060820. Inspect annually for play  and replace if detected and replace at 5 years anyway.

 Inspect Mod 51 arm for wear and replace as necessary

Inspect shock  absorbers and rubber block.  If it hops like a bunny, change the shocks, if  it sits low, change the block.  I don't know how low, low is, but the block  is about 70mm on an empty mono, so if it has lost 10 mm in height since new, it  probably needs replacing.

 Look at the long bolts Euro 26 and pins LG 04 for deformation, replace  as necessary

 Change the outrigger legs, inspect the pivot points and the locking  mechanism for corrosion and wear.  Remove and replace as necessary.

 Replace the outrigger tires/wheels if worn.

  

 I do not have a checklist for how I check the mono gear for play, and  frankly just look at the mechanics as I do not own one...  I support the  aircraft, push on the lower arm and watch the mechanism when down, especially  the locking arm.  Look at the LG 04 pin and support for cracks and  wear.  Any deformations of the gear requires replacement.  Then  partially retract the gear and check for play in the joints, wiggle the arms to  check for play, and pivot points for play (nasty dirty job), and finally  lock the gear up and check movement of the gear mechanism by pushing up on  the gear and using my bore scope to see if there are problems.  I have  never removed the mod 51, but I have also never worked on a high time  mono.  As for the outriggers, I have to look at the book if I have to take  one apart just to figure how to put it back together.  I make sure  that the gear leg locks down and that the flap moves through the proper number  of degrees before unlock.  I was not familiar with the Europa  Club bushing mod many of you had on the outriggers until Jim Butcher led me  through one.  I have only seen the standard factory build.  If there  is a comprehensive checklist other than the FAA condition inspection, I'd like  to see one for my own education.

  

 Sorry to be so long winded.

  

 Bud Yerly

 [quote]   ---

hurstkr(at)redzone.com.au
Guest

Posted: Thu Jul 15, 2010 11:34 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

FWIW, the attached photos depict what I have done.  Photos were taken during 

construction.



When the wheel is latched up, the undercarriage lever is free in the up 

detent with no load on it whatsoever.



Regards



Kingsley in Oz

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tonyrenshaw268(at)gmail.c
Guest

Posted: Fri Jul 16, 2010 8:52 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

show off



On 16/07/2010, at 5:20 PM, Kingsley Hurst wrote:



 	  Quote: 	
		   FWIW, the attached photos depict what I have done.  Photos were taken during construction.

 

 When the wheel is latched up, the undercarriage lever is free in the up detent with no load on it whatsoever.

 

 Regards

 

 Kingsley in Oz 

 <Undercarriage unlatched.JPG><19mm Sealed bearing on side of suspension trailing arm.JPG><Latch Arm with makeshift spring.JPG><Undercarriage latched up viewed from below.JPG><Undercarriage Latched up.JPG>

fklein(at)orcasonline.com
Guest

Posted: Fri Jul 16, 2010 9:44 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

On Jul 16, 2010, at 12:20 AM, Kingsley Hurst wrote:



 	  Quote: 	
		   FWIW, the attached photos depict what I have done.  Photos were  

 taken during construction.



 When the wheel is latched up, the undercarriage lever is free in the  

 up detent with no load on it whatsoever.


	


Kingsley,



As you know, I admire your work...in this case, I admire your analysis  

which anticipated the problem...of which I've been blissfully ignorant.

Do you have a pix of the pivot point along the side of the tunnel?



Fred

grahamsingleton(at)btinte
Guest

Posted: Fri Jul 16, 2010 2:28 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Good idea though ! 

From: Tony Renshaw <tonyrenshaw268(at)gmail.com>

To: europa-list(at)matronics.com

Sent: Friday, 16 July, 2010 17:51:54

Subject: Re: Europa-List: Re: Check your Landing Gear Retraction Lever Strut (Mod 51)



--> Europa-List message posted by: Tony Renshaw <tonyrenshaw268(at)gmail.com (tonyrenshaw268(at)gmail.com)>



show off



On 16/07/2010, at 5:20 PM, Kingsley Hurst wrote:



 	  Quote: 	
		   FWIW, the attached photos depict what I have done.  


	




 

  [quote][b]

hurstkr(at)redzone.com.au
Guest

Posted: Fri Jul 16, 2010 5:44 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

 	  Quote: 	
		   

 show off

 


	


Go back to your burrow Renshaw !  <g>



do not archive

hurstkr(at)redzone.com.au
Guest

Posted: Fri Jul 16, 2010 5:44 pm Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

 	  Quote: 	
		   > Do you have a pix of the pivot point along the side of the tunnel?


	


Fred,



Attached are the only two photos I have that may help.



I was a little fortunate with this project because I had at my disposal, the 

drum brake actuator from a Blanik sailplane.  The shaft that goes through 

the bush has a spline on one end and a removable square piece on the other. 

The arm you see attached to the spline is the original part off the 

sailplane so all I had to do was extend it.



The alloy bush is home made of course and goes right through the plywood 

stiffener.



I made square holes in the latch arm and the doubler to fit over the square 

on the wheel well side and stuck it all together with glue.  (to think I 

didn't even know such stuff as Redux existed before embarking on the 

Europa!!)  The square piece is discernable in one of the photos in my last 

post just below the split pin that wasn't split in the photo !



Twould be a breeze for you Fred !



Cheers

Kingsley

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hurstkr(at)redzone.com.au
Guest

Posted: Sat Jul 17, 2010 3:36 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

Fred,



 	  Quote: 	
		   > As you know, I admire your work...


	


I have just realised how ignorant I was in not acknowledging your compliment 

on the list.and I feel quite bad about it.  It was a genuine oversight on my 

part and I do apologise.

The fact that we have developed such mutual respect for each others 

abilities means a lot to me and gives me a much better feeling than what I 

have now in realising my misdemeanour.



Sorry mate.



Kingsley

fklein(at)orcasonline.com
Guest

Posted: Sat Jul 17, 2010 7:35 am Post subject: Check your Landing Gear Retraction Lever Strut (Mod 51)

On Jul 17, 2010, at 4:35 AM, Kingsley Hurst wrote:

 	  Quote: 	

 >

 Fred,

> > As you know, I admire your work...

 I have just realised how ignorant I was in not acknowledging your  

 compliment and I feel quite bad about it.  It was a genuine  

 oversight on my part and I do apologise.

Pullease Kingsley...take off the hair shirt and burn it...I'm honored  

to be considered an Aussie's "mate" on our shared Europa adventure.

Fred

do not archive

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