+20 year old donuts (1966 M20E)

[Hank]

7 hours ago, 0TreeLemur said:

One thing Jeremy, if they are that old- your aircraft is probably missing some SB items.   They added a shock link collar, and the shock links themselves can and do wear out.  The one in the nose gear of our plane was found in badly worn condition during our last annual.  That means that it wore out since the last replacement of our disks, which happened relatively recently in 2006.   We found a used one.   Good luck.

Many Mooneys have discarded the nose wheel shock link. Mine has the bumps where it was attached once upon a time.

[Pasturepilot]

9 hours ago, 0TreeLemur said:

One thing Jeremy, if they are that old- your aircraft is probably missing some SB items.   They added a shock link collar, and the shock links themselves can and do wear out.  The one in the nose gear of our plane was found in badly worn condition during our last annual.  That means that it wore out since the last replacement of our disks, which happened relatively recently in 2006.   We found a used one.   Good luck.

Thanks for this. I just woke up and grabbed the big bundle of Mooney docs in something of a panic. 

I didn't post about it but basically I went all in, and pulled the right main gear assembly when I went to replace the shock mounts. There was a good bit of surface rust where the truss had been spray painted in-situ over the years but the top of the top tube hadn't been touched. I cleaned it all up and put it all back together with my new discs this weekend. I didn't want all that work to be in vain!   Looks like the nose gear had the SB performed in November, 1984. I hadn't figured out when the main was officially done, but in digging through the pile of stuff, there was a January 1996 MAPA Log issue in a folder labeled maintenance. 

What the heck? It is folded open permanently to a LASAR advertisement and penciled in the margins there's a series of notes from a phone call with Bill at LASAR,  with part names and prices of the spacers and links for the main gear. Sure enough, I flipped to January '96 and worked forward. New main gear shock mounts and spacers in April, 1997. So my freshly cleaned and painted gear is up to speed on the SB. I think I'll go start on the left main gear now. 

On that note, any Mooney guys around ATL have the gear rigging tools I can beg, borrow, rent or steal for a few days? 

Edited May 4, 2020 by Pasturepilot
more tense conflicts than a time traveler's diary

[0TreeLemur]

 

On 5/4/2020 at 6:16 AM, Hank said:

Many Mooneys have discarded the nose wheel shock link. Mine has the bumps where it was attached once upon a time.

 You're thinking shock absorber.  The shock link is the steel rod that goes up through the middle of the discs.  Shown in Fig. 23 of the parts manual.  They wear out, at least the one in the nose gear of our bird did.

 

 

 

 

[Skydancer2992]

Size is right. Price is excellent. Wonder how they perform.

Overall Dimensions:
Diameter: 3 1/2"
Height: 1"

https://www.webstaurantstore.com/regency-3-1-2-heavy-duty-rubber-donut-bumper-for-carts-and-mobile-shelving-units/460RUBRDONT3.html

 

[LANCECASPER]

38 minutes ago, Skydancer2992 said:

Size is right. Price is excellent. Wonder how they perform.

Overall Dimensions:
Diameter: 3 1/2"
Height: 1"

https://www.webstaurantstore.com/regency-3-1-2-heavy-duty-rubber-donut-bumper-for-carts-and-mobile-shelving-units/460RUBRDONT3.html

 

Why not just use these? They're even cheaper and they probably offer about the same performance.

 

 

 

[cliffy]

1 hour ago, Skydancer2992 said:

Size is right. Price is excellent. Wonder how they perform.

Overall Dimensions:
Diameter: 3 1/2"
Height: 1"

https://www.webstaurantstore.com/regency-3-1-2-heavy-duty-rubber-donut-bumper-for-carts-and-mobile-shelving-units/460RUBRDONT3.html

 

Is this for real as a question? 

[Skydancer2992]

The manufactured cost is the main takeaway from this product. It gives an idea of the potential profit that Lord and its distributors are partaking.

Most likely, the disk in this add is a generic product, manufactured in the millions.

This particular dealer is selling the disk for the cart bumper application. Some may be prejudiced by that application.

As far as this donut, locating the manufacturer and obtaining test data would help determine the whether it's physical characteristics are similar to those of the original Firestone or the later Lord disks.

[N201MKTurbo]

If it cost nothing to make these, the price to us would probably be the same. You guys don't understand manufacturing.

If you can operate a business making FAA certified doughnuts for Mooney's, knock your lights out!

How many do you think they sell a year? A couple of thousand, maybe. Yet they still need to have all the stuff to run a business to sell a few thousand parts.

You can't hardly keep the lights on for $200,000/year. and that's assuming the $100 each is pure profit!

The Chinese company that makes those rubber bumpers, probably make millions a year on a dedicated line. I imagine Lord does one or two runs a year on the Mooney doughnuts. It probably takes more time to set up the equipment than make them.

[cliffy]

First off a "generic" product has no FAA approval for manufacture. 

Don't even think about going standard part.

There is a guy here on MS that "might" be able to pull it off "owner designed" but the price will be no where near $10. 

Not only do you not understand manufacturing you have no knowledge of what making a part for a certified airplane requires. This  ain't your father's 56 Chevy. Auto Zone can't supply the parts to you.

There is a reason why airplane "stuff" costs so much money. 

A manufacturer has to submit an entire program for approval of inbound and out bound inspection, raw material tracking, a fixed place of business, hard evidence that the part being made complies with the approved design in all aspects. Its called a PMA The FAA requires traceability back to birth for each part. 

Now, the first issue I saw on these Dunkin' donuts is the fact that there are NO steel plates molded to each rubber disc like the Lord units thereby negating even a question as to their suitability to be installed on a certified airplane.

All rubber is not the same. What is the composition (for wear and aging ability)?  What is the durometer rating for load carrying ability? 

Where is the PMA?   

All the above is what we have to think about when looking for parts form our 60 year old airplanes made by a company that is OUT OF BUSINESS!

We are actually lucky that there is a company that is WILLING to make a consumable FAA approved product for a half century old piece of equipment from a defunct airplane manufacturer with a very small market presence.  In the big scheme if things, they don't need us- WE need them. 

 

[LANCECASPER]

If it was easy everyone would be doing it . . . 

Every person who has a driver’s license would have their pilot’s license. Every manufacturing company making car parts would be making airplane parts.

[tmo]

FWIW, I think it takes less hours (28) to get a ultralight plane license (that includes specimens such as this 200kt 2-seater) than a driver's license (30).  Then again, you could probably use those pucks in a UL plane, if they weren't too heavy...

[Guest]

Univair of Colorado seems to be able to sell approved gear shock discs for Ercoupes for under $10.00

[cliffy]

No metal discs on each side and they have the specs to make the approved part. 

Maybe they will at some time be able to buy the intellectual property of  Mooney and start making parts for us like they do for other orphan airplanes.   

Would probably be a good business model

[Guest]

I’m searching for the Holy Grail of Mooney Mite parts, landing gear shock discs.  Luckily the Mite discs aren’t bonded to the washers, so I only need the donuts.

Clarence

[carusoam]

12 hours ago, Skydancer2992 said:

The manufactured cost is the main takeaway from this product. It gives an idea of the potential profit that Lord and its distributors are partaking.

Most likely, the disk in this add is a generic product, manufactured in the millions.

This particular dealer is selling the disk for the cart bumper application. Some may be prejudiced by that application.

As far as this donut, locating the manufacturer and obtaining test data would help determine the whether it's physical characteristics are similar to those of the original Firestone or the later Lord disks.

 

1 hour ago, M20Doc said:

I’m searching for the Holy Grail of Mooney Mite parts, landing gear shock discs.  Luckily the Mite discs aren’t bonded to the washers, so I only need the donuts.

Clarence

There is a rubber parts manufacturer around here that has done the analysis on existing donuts...   Both chemistry and physical properties...

he is in South Africa...

There is a thread in the Mite section for donuts... I have pointed the rubber guy towards that thread...

Essentially, a rubber disc can be duplicated, just not accidentally...  very unlikely to be accidentally copied...

Even though the original donuts were borrowed from a Mack truck engine or something like that...

It is quite possible that these could be owner produced parts...

Does anyone want to be first..?

PP thoughts only, not a rubber guy...

Best regards,

-a-

[carusoam]

See if @Gert is stopping by... I believe he is the rubber man.

Best regards,

-a-

 

[Browncbr1]

I’m waiting for someone else to the the guinea pig on Gert’s discs.   If I could do new discs all around for $500, I would have already.  

[carusoam]

See if we can crowd fund some owner produced parts.... We have had good success doing this before...

See if David (Or another mechanic) wants to put them on his plane...

The results would be....

• Owner produced parts
• crowd funded design copy effort
• put on a mechanics plane (Owner)
• by a mechanic
• parts are as near to identical as physically possible (matching the owner produced definition)
• For the effort... the mechanic keeps the newly purchased donuts...
• If things don’t work as expected... mechanic has the ability to put the old donuts back on... or any other donut he chooses...
• If a hundred MSers threw a day’s lunch money to organize the project...

This could possibly happen...

I mentioned David, because he has the experience of organizing the owner supplied parts project for the up lock block....

Best regards,

-a-

[tmo]

6 hours ago, Browncbr1 said:

I’m waiting for someone else to the the guinea pig on Gert’s discs.   If I could do new discs all around for $500, I would have already.  

I am in contact with @Gert and will be talking with my A&P/IA about this no later than June when we do an EDM install.  If anyone else is considering an order, let's sync up and optimize the process for Gert.

[Gert]

I have now sucessfully manufactured the Mooney discs and they are ready to ship. these discs are much more robust than the original Lord discs as the elastomer/rubber compound is much more stable and will have a longer lifespan. They are similar in design as the Beechcraft type, but of a different material mix. Accelerated ageing and UV tests have been conducted with excellent results. These discs will outlast any other. It is not advisable to paint them as the solvents might damage the compound. Some AMO's spray the discs with silicone before installation as this will assist in reducing abrasion. Visit www.avunlimited.co. 

Best Regards

Gert

[KB4]

Can you share your data or whatever it is you are using as basis of claim that they outlast any other.  At half the cost, if your claims hold true, this is an awesome alternative to Lord.

[Andy95W]

2 hours ago, KB4 said:

Can you share your data or whatever it is you are using as basis of claim that they outlast any other.  At half the cost, if your claims hold true, this is an awesome alternative to Lord.

I, too, would like to know this, but admit the product looks pretty good.

My concerns:

-I don't know what FAA-OPP is supposed to signify as any sort of legal pronouncement.  Perhaps the lettering is supposed to make the owner/inspector feel like it is more legal than it actually is.

-The rules for an owner produced part is that it is supposed to be constructed out of the same material as the original. This is why the new Johnson gear lock blocks went through such a rigmarole trying to determine the exact alloy of the originals.  But Gert, above, states outright that these new discs are more robust/more stable/longer lifespan than Lord discs.  How does that make them the same material as the original?

-The lettering on the discs does not include the C, but on the website it does.  Seems like a small of an oversight, but if something as easy as that was missed, it makes me begin to question more aspects of product.

I like the idea and the look of these discs, I'm just not going to be the first to install them.  Or the second, for that matter.  But in 10 years, who knows?

[EricJ]

Just now, Andy95W said:

-The rules for an owner produced part is that it is supposed to be constructed out of the same material as the original.

There's no requirement that the materials be identical, just that the part has the same characteristics to return the aircraft to "at least equal" to the original or properly altered condition.  Note that exceeding original or properly altered condition is allowed.   It doesn't have to be the same.

I share the concerns on these parts, though.   How the owner is participating in production via the requirements is not clear.   How the installer can determine that the part will perform as well as the original also isn't clear.

 

[cliffy]

On 4/29/2020 at 3:31 AM, Gert said:

I manage to stumble onto the original manufacturing specifications of the Beechcraft as well as Mooney discs. The manufacturing data and rubber composition for both discs were made available by a retired engineer from Lord who used to manufacture these discs. The Mooney discs have the same composition as the Beechcraft discs of the natural rubber and  percentage Poly-butyl-dye-lean which is slightly more dampened and stiffer. 

Above is a cut from Gert's above post where he finds the original specs for the Mooney discs. 

Below I have tagged on an article by Bill O'Brian (deceased) the guru of GA maintenance for many years with the FAA on OPP Owner Produced Parts and what has to be done. 

If you go to Question 6 and his answer - one needs to confirm that the part being made conforms to its approved design of which it seems that Gert has a copy. 

I would think that there would be no issue if the owner "participated" in the design process (as required) by sending a letter to Gert specifying that new donuts be made to the original design specs he has and then retaining a copy of the letter for the aircraft records and (as noted in Bill O'Brian's letter) the owner makes a log book entry saying he/she has supplied an OPP part for installation on his/her airplane only. The A&P also needs to inspect the part (as noted in Bill's letter) and sign off the installation. (read the below letter)

This is no different than getting a mixture control made by McFarlane to OPP design and having the A&P install it. 

And, as he has been doing it for a number of years on Beech airplanes with apparently no issues at this point I see no problems. If it had been 6 months ago I probably would have gone through him for mine. 

 

HERE IS ANOTHER THOUGHT I HAVE NOT SEEN PROPOSED YET FOR US WITH MOONEY BEING SHUT DOWN-

In question 8 in Bill's letter he talks about FOIA request for the design sheets for parts not available from defunct companies.

Maybe we need to pursue this avenue for parts we can't readily get anymore. 

Answer 8: For aircraft that the manufacturer is no longer supporting the continuing airworthiness of, the owner or operator can petition the FAA Aircraft Certification Directorate under the Freedom of Information Act for the data on how the part was made.

 

Interesting article by Bill O'Brien who is an Airworthiness Aviation Safety Inspector in FAA's Flight Standards Service. (BELOW)

by Bill O'Brien

Along with the pilot shortage and the mechanic shortage, there is also a parts shortage that plagues the general aviation industry. Because supply and demand are out of balance the cost of new and used parts seem to increase every day. Let's examine the reasons why this is so.

First, we have an old fleet. The average general aviation (GA) single engine airplane is approximately 32 years old. The average age of GA multi-engine reciprocating aircraft is close to 27 years old. The average age for the turbine powered multi-engine propeller driven aircraft average out around 19 years of age. So because of long term wear and tear the demand for replacement parts and large sub-assemblies is much greater today than it was even 10 years ago.

The second reason is our general aviation fleet has been well maintained over the years. So well maintained in fact, the average GA aircraft with a mid-time engine and decent avionics has appreciated to two or three times its original purchase price and is still climbing. Yet even in that land of many zeros the older aircraft are still substantially lower in price than the cost of a brand new aircraft with similar performance numbers and equipment. So the value of older aircraft in good shape are proven investments that over time have beaten the DOW JONES average. So we have an economic imperative on the part of the owners to keep maintaining older aircraft in flying condition which increases the demand for replacement parts.

The third reason is the increasing production costs to make a part. Today aircraft manufacturers are not making makes and models of aircraft in the same quantity they made them back in the Seventies. So the production runs for parts are not as frequent and not as many parts are produced. In addition, it is not cost effective for a manufacturer to make a lot of parts even if the unit price for each part is out of this world because taxes on maintaining a large inventory of parts would eat all of the profits. This low parts production keeps the supply of replacement parts low.

The fourth reason is that some manufacturers would prefer that their older makes and model aircraft-made a million years ago-would quietly disappear from the aircraft registry. This retroactive birth control on the part of the manufacturers may seem not to make any sense until you look at aircraft market dynamics of creating demand and reducing costs. First, each older aircraft that is no longer in service creates a demand for a new, more expensive aircraft to take its place. Second, despite some tort claim relief granted to GA manufacturers in the early Nineties, the fewer older aircraft there are in service, the manufacturers of those aircraft enjoy reduced overall liability claims and ever decreasing continuing airworthiness responsibilities.

So how are we going to maintain these older aircraft with an ever dwindling parts supply when Part 21, section 21.303 Replacement and modification of parts, requires us to use the Parts Manufactured Approval (PMA) parts on a type certificated product? Well, the same rule grants four exemptions to the PMA requirement.

1. You can use parts produced under a type or production certificate such as a Piper, Cessna, or Mooney produced part;

2. A owner or operator produced part to maintain or alter their own product;

3. Parts produced under a Technical Standard Order (TSO) such as radios, life vests and rafts, and GPS; or,

4. A standard aviation part such as fasteners, washers, or safety wire.

Before I segue into the subject of "owner produced parts" as called out in section 21.303, which is the purpose of this article. I would like to create a small uproar with this statement: "FAA Airframe and Powerplant rated mechanics can maintain, repair, and modify parts, but they cannot make a brand new part and call it a repair." Before you accuse me of losing dendrites by the minute, check out section 65.81 General privileges and limitations. The section talks about maintenance, preventive maintenance, and alterations, but not the manufacturing of parts. Nor is it an implied privilege in Part 65, because Part 21 section 21.303 says "no person" may make a replacement part for a type certificated (TC) product unless that person has a PMA, etc.

While I write this I can remember 25 pounds ago and when I had hair, I worked in the real world and I specialized in making engine baffles for Lycoming engines. Before someone accuses me of bureaucratic ventriloquism which is roughly translated as "talking out of both sides of my mouth." My weak defense is, I made the parts because I thought I could." It never dawned on me that I could not legally make a part. Some of you may be astounded that I make this confession freely. It's no big thing because I know the statue of limitations has run out years ago and a jury of my peers would never look me in the eye and convict me.

So here is our problem that we must solve. Since mechanics cannot legally make parts for aircraft and aircraft need replacement parts, how are we going to keep the fleet flying? If we cannot find PMA, TSO, standard, or production holder replacement parts, we are left to make the part under the owner-produced option under section 21.303(b)(2). However, we must remember that the part is for the owner/operator's aircraft only and is not manufactured for sale to other TC aircraft.

To get through confusing regulatory policy with our pride intact, let's try the question and answer routine. (Note: This policy is taken from FAA 's AGC-200 policy memorandum to AFS-300 on the definition of "Owner-Produced Parts" dated August 5, 1993)

Question 1: Does the owner have to manufacture the part him or herself in order to meet the intent of the rule?

Answer 1: No, the owner does not have to make the part him or herself. However to be considered a producer of the part he/she must have participated in controlling the design, manufacturer, or quality of the part such as:

1. provide the manufacturer with the design or performance data from which to make the part, or

2. provide the manufacturer with the materials to make the part, or

3. provide the manufacturer with fabrication processes or assembly methods to make the part, or

4. provide the quality control procedures to make the part, or

5. personally supervised the manufacturer of the part.

Question 2: Can the owner contract out for the manufacture of the part and still have a part that is considered "owner-produced?"

Answer 2: Yes, as long as the owner participated in one of the five functions listed in Answer 1.

Question 3: Can the owner contract out the manufacture of the part to a non-certificated person and still have a part that is considered "owner-produced?"

Answer 3: Yes, as long as the owner participated in one of the five functions listed in Answer 1.

Question 4: If a mechanic manufactured parts for an owner, is he/she considered in violation of section 21.303(b)(2)?

Answer 4: The answer would be no, if it was found that the owner participated in controlling the design, manufacture, or quality of the part. The mechanic would be considered the producer and would not be in violation of section 21.303(a). On the other hand, if the owner did not play a part in controlling the design, manufacture, or quality of the part, the mechanic runs a good chance of being in violation of section 21.303 (b)(2).

Question 5: What kind of advice can you give on how a mechanic can avoid even the appearance of violating section 21.303(b)(2)?

Answer 5: First, a mechanic should never make a logbook or maintenance entry saying that he/she made a part under his certificate number. This foopah will send up a flare and get you undue attention from your local FAA inspector, which you could do without. However, the mechanic can say on the work order that he helped manufacture an owner-produced part under section 21.303 (b)(2).

Second, the owner or operator should be encouraged to make a log book entry that is similar to section 43.9 maintenance entry that states: The part is identified as an owner produced part under section 21.303 (b)(2). The part was manufactured in accordance with approved data. The owner/operator's participation in the manufacturer of the part is identified, such as quality control. The owner must declare that the part is airworthy and sign and date the entry.

Question 6: Is there anything else a mechanic must do?

Answer 6: The mechanic must ensure that the owner-produced part meets form, fit, and function, and, within reasonable limits, ensure that the part does meet its approved type design (e.g. like looking at the approved data used to make the part). Then the mechanic installs the part on the aircraft, makes an operational check if applicable, and signs off the required section 43.9 maintenance entry.

Question 7: What is the owner responsible for and what is the mechanic responsible for concerning owner-produced parts?

Answer 7: The owner is responsible for the part meeting type design and being in a condition for safe operation. The mechanic is responsible for the installation of the owner-produced part being correct and airworthy and for a maintenance record of the installation of the part made.


Question 8: How does the owner or operator get the approved data to make a part if the manufacturer and other sources are no longer in business?

Answer 8: For aircraft that the manufacturer is no longer supporting the continuing airworthiness of, the owner or operator can petition the FAA Aircraft Certification Directorate under the Freedom of Information Act for the data on how the part was made. Or the owner or operator can reverse engineer the part and have the data approved under a FAA field approval or, if it is a really complicated part, have the data approved by a FAA engineer or FAA Designated Engineering Representative.

Question 9: What happens to the owner-produced part on the aircraft if the original owner sells the aircraft?

Answer 9: Unless the part is no longer airworthy, the original owner-produced part stays on the aircraft.

I hope that I spread some light on the murky subject of owner-produced parts, so the next time instead of saying to the owner of an broke aircraft: "Sure, 'I' can make that part," you will now say "Sure, 'WE' can make that part."




--------------------------------------------------------------------------------
Bill O'Brien is an Airworthiness Aviation Safety Inspector in FAA's Flight Standards Service. This article also appeared in the Aircraft Maintenance Technology magazine.
 

Edited May 24, 2020 by cliffy

[Andy95W]

Thanks to Cliffy and Eric.  I think these will probably be quite good as an alternative. (I'm still not going to go first, but am anxious to hear from someone who does.)