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Repair schemes for undercarriage


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Hi All

I have some damage on both my main landing gear spindle assemblies (that's how they are identified in the PC) essentially the bit with the axle. The damage, most likely, has been there for some time and requires material build up rather than fixing a crack or break.

My understanding is that these components are heat treated and our aircraft welders (all three of them) here in Oz are reluctant to do anything unless there is a recognised repair scheme or you pay many thousands of dollars for an engineering order.

I am aware of the AC 43 which covers generic maintenance practices and repairs suitable for GA, however, I would appreciate if someone could provide some guidance on the following:

1. Is the AC 43 adequate?

2. Is there a specific Mooney repair scheme available?

3. Does someone have a "go to welder" with an approved repair method or scheme?

4. Has anyone done a repair to the MLG?

If the information is readily available could someone please point to where I could acquire it.

If someone has paid for a repair scheme ie research, testing and approval, I would be happy to throw some $$$ their way to gain access.

My other option is obviously to get new parts from what has been recently discussed a near impossibility. Used items would be hit or miss with the term "in good condition" treated with some skepticism.

Look forward to hear what people have to say.

Cheers

Barneyw

 

   

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2 hours ago, 67 m20F chump said:

Would it be possible to get used ones shipped?

Yes always possible just finding ones in good condition. The one thing that is killing freighting stuff from the US is the freight charge itself which be $4-500 just for a small box. People in the US are loathed to use USPS for international shipments for whatever reason.

Cheers

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6 hours ago, Barneyw said:

Hi All

I have some damage on both my main landing gear spindle assemblies (that's how they are identified in the PC) essentially the bit with the axle. The damage, most likely, has been there for some time and requires material build up rather than fixing a crack or break.

My understanding is that these components are heat treated and our aircraft welders (all three of them) here in Oz are reluctant to do anything unless there is a recognised repair scheme or you pay many thousands of dollars for an engineering order.

I am aware of the AC 43 which covers generic maintenance practices and repairs suitable for GA, however, I would appreciate if someone could provide some guidance on the following:

1. Is the AC 43 adequate?

2. Is there a specific Mooney repair scheme available?

3. Does someone have a "go to welder" with an approved repair method or scheme?

4. Has anyone done a repair to the MLG?

If the information is readily available could someone please point to where I could acquire it.

If someone has paid for a repair scheme ie research, testing and approval, I would be happy to throw some $$$ their way to gain access.

My other option is obviously to get new parts from what has been recently discussed a near impossibility. Used items would be hit or miss with the term "in good condition" treated with some skepticism.

Look forward to hear what people have to say.

Cheers

Barneyw

 

   

Do you happen to have pictures of the damage you are trying to repair? 

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1 hour ago, Barneyw said:

Yes always possible just finding ones in good condition. The one thing that is killing freighting stuff from the US is the freight charge itself which be $4-500 just for a small box. People in the US are loathed to use USPS for international shipments for whatever reason.

Cheers

All international shipments are extremely complicated with each country having different requirements. It’s a nightmare. 
David

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1 hour ago, takair said:

Do you happen to have pictures of the damage you are trying to repair? 

No. It looks like that there may have been a bearing failure and the brake disc grounded away part of the vertical section of the spindle assy. From what the mechanic told me the tube wall thickness is 0.200 and the damage is close to 50% of the wall thickness. The damage would be akin to someone taking an angle grinder to a piece of tube and touch it and put a sizeable nick in it maybe around 1/2 - 3/4" wide and less than an inch long. My sense, and with limited welding experience, I feel that it can be as simple as building up the thickness again and then heat treating the spindle.

Anyhow I'm hoping there is a repair scheme out there.

Cheers  

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18 minutes ago, PT20J said:

You could also contact the factory for repair instructions. I have done this for airframe repairs and Frank Crawford was very responsive.

Ok i'll try that personally but I was told that it wasn't available. I will give it a go. Thanks

Cheers

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9 hours ago, Barneyw said:

Hi All

I have some damage on both my main landing gear spindle assemblies (that's how they are identified in the PC) essentially the bit with the axle. The damage, most likely, has been there for some time and requires material build up rather than fixing a crack or break.

My understanding is that these components are heat treated and our aircraft welders (all three of them) here in Oz are reluctant to do anything unless there is a recognised repair scheme or you pay many thousands of dollars for an engineering order.

I am aware of the AC 43 which covers generic maintenance practices and repairs suitable for GA, however, I would appreciate if someone could provide some guidance on the following:

1. Is the AC 43 adequate?

I'm assuming you mean AC 43.13, which is sort of the mechanic's bible when it comes to repair data.    The cover page of AC 43.13 says it can be used as approved data under certain conditions:

The repair data may also be used as approved data, and the AC chapter, page, and paragraph listed in block 8 of FAA form 337 when:
a. the user has determined that it is appropriate to the product being repaired;
b. it is directly applicable to the repair being made; and
c. it is not contrary to manufacturer’s data.

I don't know what the F model SMM says, but for the J model the SMM indicates that the gear legs are heat-treated and a NOTE right after that description that says:

Heat-treated components should NOT be repaired; replace them.

So part c excludes repairing at least J model landing gear using AC 43.13 repairs as approved data (and any other models with similar guidance in the SMM).   This does not exclude using a DER to develop an approved repair.   As you mention, if somebody else has developed a repair and gotten it approved, that may provide a path for another approval through a DER or other route.

I don't know how well any of that plays in your regulatory environment, though.

Finding a used one may be the best route.  ;)

 

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2 hours ago, Barneyw said:

No. It looks like that there may have been a bearing failure and the brake disc grounded away part of the vertical section of the spindle assy. From what the mechanic told me the tube wall thickness is 0.200 and the damage is close to 50% of the wall thickness. The damage would be akin to someone taking an angle grinder to a piece of tube and touch it and put a sizeable nick in it maybe around 1/2 - 3/4" wide and less than an inch long. My sense, and with limited welding experience, I feel that it can be as simple as building up the thickness again and then heat treating the spindle.

Anyhow I'm hoping there is a repair scheme out there.

Cheers  

Oh wow. Ok. I can certainly picture that. You might consider one of the aerospace welding shops that does engine mounts and such. They often have DERs on staff and can determine heat treat required. I think I’ve heard recently that ACS does nose trusses now, so this is not that far off. Another company used to be Kasolo (sp?). Don’t know if they  are around. As others suggested, my guess is surplus will be fastest. Then you can get these repaired in a leisurely manner. 

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On 9/29/2024 at 6:26 AM, Barneyw said:

Yes always possible just finding ones in good condition. The one thing that is killing freighting stuff from the US is the freight charge itself which be $4-500 just for a small box. People in the US are loathed to use USPS for international shipments for whatever reason.

Cheers

Good day,

I have a left side spindle assembly and will check in for a right side when I get to my shop in a week or so. Would be willing to sell this and ship if you’re interested.

David

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