Life Limits

[Hank]

11 minutes ago, aviatoreb said:

Carbon is no better or worse than the other stuff.  None.  Its how well its engineered.  And good engineers a this point understand very well how each of these materials is stressed, ages, and so forth and how much margin to build in when selecting materials and selecting how much to build and over build into their designs based on expected stresses. 

Anything that one man can build, another man can break. Will it be your turn today? Tomorrow? Next week?

Ain't nothing perfect, and nothing lasts forever.

Don't want your airplane to break? Don't buy an airplane . . . . Same for a car, bicycle, tool or appliance. Eventually, everything with a power cord will end up in the landfill.

[Schllc]

30 minutes ago, aviatoreb said:

Much of what you say is true but some is not my experience at all.

I have seen aluminum fail completely too, as well as steel, but at least in my experience, it was always with ample warning. 
I rode mountain bikes, I also built them and did all of my own work and I would always look at critical areas before a ride, and when a waddled out headset, crank bearing hosuing, or rear axle hangar was going you would know because the bearings would move and creak or make noises, or you could fed the wobble, or see a crack starting,
the carbon fiber bikes I saw fail never really showed signs of weakness or damage before failure. 
I agree with you about the design, and as I said bicycle manufacturers don’t likely spend the time or money testing to the degree and airplane manufacturer would so this could likely account for my experience, and is a small sample. 
I would not go as far as to say I do not trust planes made of carbon fiber.  After all I have more than a few hours in cirrus aircraft. 
I would not however buy one for myself.  I prefer the things I understand better, and while it’s likely an abundance of caution it’s just my preference. 

[aviatoreb]

29 minutes ago, Hank said:

Anything that one man can build, another man can break. Will it be your turn today? Tomorrow? Next week?

Ain't nothing perfect, and nothing lasts forever.

Don't want your airplane to break? Don't buy an airplane . . . . Same for a car, bicycle, tool or appliance. Eventually, everything with a power cord will end up in the landfill.

I couldn't agree more highly.

With enough noodles we could build an airplane out of noodles.  The big question then would be, angel hair or fettuccini.

Edited May 3, 2023 by aviatoreb

[ChatGPT]

Yes, Mooney aircraft, like most other GA aircraft, have life limits and maintenance requirements that are designed to ensure safe operation over the life of the aircraft. These limits are typically based on a combination of factors, including flight hours, cycles (takeoffs and landings), and calendar time.

The specific life limits for a Mooney aircraft can be found in the aircraft's maintenance manual or other technical publications. These limits may vary depending on the specific model and year of the aircraft, as well as any modifications or upgrades that have been made.

In addition to life limits, Mooney and other GA aircraft require regular inspections and maintenance to ensure safe operation. This may include looking for signs of fatigue or cracks in the airframe, which can be caused by stress from flight operations or other factors such as corrosion or aging.

It's important for owners and operators of Mooney aircraft, particularly those with higher flight hours, to follow the manufacturer's recommended maintenance and inspection schedule, and to work with qualified mechanics and maintenance personnel to ensure the aircraft is safe and airworthy.

While there may be service life extension programs or other means to extend the life of military aircraft such as the F-18, the same approach may not be applicable to GA aircraft like the Mooney. Nonetheless, with proper maintenance and care, Mooney aircraft can remain safe and reliable for many years of operation.

[CapPJ]

So prelim on the PPI for the 10K hour M20J showed some potential cracks on the weld joints of the MLG trunnions. Both sides apparently. I don't know if this is fixable or needs complete replacement of the metal. Has anyone seen this or been down this path?

[Hank]

3 hours ago, ChatGPT said:

Yes, Mooney aircraft, like most other GA aircraft, have life limits . . .

The specific life limits for a Mooney aircraft can be found in the aircraft's maintenance manual or other technical publications.

No Mooney parts are life-limited. If you have found some, please post the part number, the part name, the life limit and your source of information.

The Mooney Type Certificates and Maintenance Manuals certainly do not show any.

The rest of your lengthy post is general.observations about things, and has nothing to do with life limits of Mooney aircraft. Please stop posting rubbish like this!

I'm hoping that your human assistant will see this and butt the hell out!

[KSMooniac]

28 minutes ago, CapPJ said:

So prelim on the PPI for the 10K hour M20J showed some potential cracks on the weld joints of the MLG trunnions. Both sides apparently. I don't know if this is fixable or needs complete replacement of the metal. Has anyone seen this or been down this path?

In the past, LASAR would rebuild/exchange/sell nose gear parts that are more susceptible to wear and tear.  They had a jig for welding and approval for heat treatment.  I do not know if they're still doing that, or if they could restore MLG steel parts under their approval authority.  I would ask them first.  The other option is buying salvage parts from a lower time bird, of which there should be quite a few available at any given time.  My current favorite salvage operator is Beegles in CO.  

An MSC might have a line on whether or not the factory service center could repair these too, although it likely won't be economical or quick.  If it were me, I'd source good salvage ones, and then figure out how to repair these for spares.  I would not let this be a deal-breaker if the rest of the plane looks good, but it is an airworthy item for the seller to address.

As mentioned many times in this thread, Mooneys do not have an official fatigue life, nor have there been reports of fatigue cracking like some other manufacturers.  Corrosion is our biggest enemy.  The wear items on a Mooney are things like the rubber donuts, engine isolators, Heim joints, jack screws, gear actuators, and NLG parts, and perhaps these MLG parts on very high time or abused planes.  The good news is that these are fairly reasonable to service/replace, versus a fatigued spar or fuselage frame.  

[RoundTwo]

47 minutes ago, CapPJ said:

So prelim on the PPI for the 10K hour M20J showed some potential cracks on the weld joints of the MLG trunnions. Both sides apparently. I don't know if this is fixable or needs complete replacement of the metal. Has anyone seen this or been down this path?

Those are beyond potential, they’re actual. I’m not a mechanic, but I would assume that renders the aircraft unairworthy and this would fall onto the seller to correct as a condition of sale. Good job on finding these.

[kortopates]

In the past, LASAR would rebuild/exchange/sell nose gear parts that are more susceptible to wear and tear.  They had a jig for welding and approval for heat treatment.  I do not know if they're still doing that, or if they could restore MLG steel parts under their approval authority.  I would ask them first.  The other option is buying salvage parts from a lower time bird, of which there should be quite a few available at any given time.  My current favorite salvage operator is Beegles in CO.  
An MSC might have a line on whether or not the factory service center could repair these too, although it likely won't be economical or quick.  If it were me, I'd source good salvage ones, and then figure out how to repair these for spares.  I would not let this be a deal-breaker if the rest of the plane looks good, but it is an airworthy item for the seller to address.
As mentioned many times in this thread, Mooneys do not have an official fatigue life, nor have there been reports of fatigue cracking like some other manufacturers.  Corrosion is our biggest enemy.  The wear items on a Mooney are things like the rubber donuts, engine isolators, Heim joints, jack screws, gear actuators, and NLG parts, and perhaps these MLG parts on very high time or abused planes.  The good news is that these are fairly reasonable to service/replace, versus a fatigued spar or fuselage frame.  

LASAR has lost its PMA status since moving to Oregon and is supposedly going through the process to get it back.


Sent from my iPhone using Tapatalk

[aviatoreb]

3 hours ago, Hank said:

No Mooney parts are life-limited. If you have found some, please post the part number, the part name, the life limit and your source of information.

The Mooney Type Certificates and Maintenance Manuals certainly do not show any.

The rest of your lengthy post is general.observations about things, and has nothing to do with life limits of Mooney aircraft. Please stop posting rubbish like this!

I'm hoping that your human assistant will see this and butt the hell out!

That’s what chatgpt does in general - makes false statements with complete authority.

[EricJ]

4 minutes ago, aviatoreb said:

That’s what chatgpt does in general - makes false statements with complete authority.

It's what the people want!   

 

 

[aviatoreb]

29 minutes ago, EricJ said:

It's what the people want!   

 

 

Sadly it’s true / just look at the most popular tv “news” outlets.  Look at our politicians.  Who voted for the liars?  The people.

[aviatoreb]

Chatgpt for president.

[ilovecornfields]

3 minutes ago, aviatoreb said:

Chatgpt for president.

ChatGPT is a communist. Google Bard in 2024!

[PT20J]

4 hours ago, CapPJ said:

So prelim on the PPI for the 10K hour M20J showed some potential cracks on the weld joints of the MLG trunnions. Both sides apparently. I don't know if this is fixable or needs complete replacement of the metal. Has anyone seen this or been down this path?

I know Mooney is currently manufacturing ten nose gear legs. I don't know what MLG parts they may have in stock, but you could check with Frank Crawford, support@mooney.com. Perhaps @M20Doc has seen this, but this doesn't seem a common problem here on MS and I would proceed under the assumption that the airplane may have been subjected to a very hard landing and inspect for other possibly hidden damage. I would not purchase an airplane in this condition -- it doesn't appear airworthy and the seller should fix it.

[Pinecone]

The crack should be easily welded.

The concern I would have is if there is corrosion inside the tube

[PT20J]

Has to be heat treated.

[Fly Boomer]

On 5/5/2023 at 2:53 PM, PT20J said:

Has to be heat treated.

Now that LASAR is essentially out of the picture, does anyone know the specifications for heat treating?

[carusoam]

Nice catch on the weld crack issue!

Firm up a fix plan before taking on the responsibility of ownership…

Weld cracks have been seen before, but they are not very common…

Other places weld cracks have been seen include engine mounts…

PP thoughts only, not a mechanic…

Best regards,

-a-

[T. Peterson]

On 1/30/2020 at 8:07 PM, Yetti said:

You say these airframes are not being stressed.  Have you seen some of these people land?

Stop spying on me!