SB M20-345

[Sheriff23]

On 10/10/2022 at 12:32 PM, DCarlton said:

A bit of a tangent, but how are the weights attached?   They look like big steel rivets.  Mine have a tad of corrosion so I’m assuming steel.  Wondering how those get squeezed or pounded.  I don’t think I saw the fasteners in the parts manual.  

I am told they are secured with Iron rivets.  My 67F has the hybrid weights and they're in bad shape.  I am trying to source some from various salvage companies.  After speaking with Mooney they said you can replace them, but you have to replace both and it affects the balance/moment, so we will be doing some homework with mooney to ensure it is reflected properly.

[redrider54]

New to all this. If mine doesn't have have hybrid weights. Can I just fill out post card and send back or do I need an A&P or IA to sign it and send in?

[EricJ]

25 minutes ago, redrider54 said:

New to all this. If mine doesn't have have hybrid weights. Can I just fill out post card and send back or do I need an A&P or IA to sign it and send in?

You don't need to do anything.    It's just a Service Bulletin, so compliance is not required for Part 91 operators like us.   If it was an AD you'd be required to follow it.   If you have a hybrid counterweight and it's coming apart it'd be smart to not fly it.    If you don't have a hybrid counterweight you don't really need to do anything.

 

[Parker_Woodruff]

Please don't home-cook anything with this, MS friends.  Control balance is nothing to mess with.  There are planes popping up with this issue all over the place.  It amazes me that these things haven't been caught in shops up until the factory saying something.

[EricJ]

3 hours ago, Parker_Woodruff said:

Please don't home-cook anything with this, MS friends.  Control balance is nothing to mess with.  There are planes popping up with this issue all over the place.  It amazes me that these things haven't been caught in shops up until the factory saying something.

A weight slug isn't something you normally expect to have to inspect for loss of integrity, though.    Nevertheless, glad it's getting attention now!

[1980Mooney]

1 hour ago, EricJ said:

A weight slug isn't something you normally expect to have to inspect for loss of integrity, though.    Nevertheless, glad it's getting attention now!

I guess I don't understand the point.  Don't you put your eyes on everything for corrosion? - interior frame, engine mounting frame, exhaust, control rods, landing gear, prop, internally in wing structures, under the rear seat on the wing spar from spilled corrosive drinks and most easily on the exterior - looking for filiform corrosion creeping from the edges and around rivets.  This corrosion in the pics is easy to see - why won't it be spotted in an annual?

[DCarlton]

9 minutes ago, 1980Mooney said:

I guess I don't understand the point.  Don't you put your eyes on everything for corrosion? - interior frame, engine mounting frame, exhaust, control rods, landing gear, prop, internally in wing structures, under the rear seat on the wing spar from spilled corrosive drinks and most easily on the exterior - looking for filiform corrosion creeping from the edges and around rivets.  This corrosion in the pics is easy to see - why won't it be spotted in an annual?

Makes sense to me since they isolated it to a specific component and production lot.  No harm in focusing attention.  Mooney has a great reputation for airframe integrity.  Why tarnish it with potential unexplained inflight failures.  I’m no expert in the process though.  

[N201MKTurbo]

I got an email from LASAR today saying they could fix this problem. The ad had a picture of a Cessna on it.

[A64Pilot]

For the iron rusting rivets use a rust stop as a primer, it stops it from coming back. Cleaning and priming it will eventually come back.

I’ve never balanced a flight control leading edge heavy, but then I’ve only done low speed aircraft nothing that goes real fast so maybe that’s why.

Don't do this yourself guys, your going to need an A&P to make the entries anyway, get them to verify the balance with the new weights.

Source of lead for casting is often old tire weights, it’s alloyed with something making it stronger and tougher, made good bullets as pure lead is awful soft and smears in a barrel. I’ve heard California doesn’t use lead tire weights anymore?

I’d assume Mooney weights aren’t pure lead? Maybe that’s what the hybrid weights are about, outer casing for strength inner for weight?

My 81 J has the iron rivets on all three surfaces, Driving Iron isn’t so bad, Monel rivets suck, they work harden real easy so you can’t be gentle with them. You see them in stainless steel like firewalls.

[A64Pilot]

20 hours ago, redrider54 said:

New to all this. If mine doesn't have have hybrid weights. Can I just fill out post card and send back or do I need an A&P or IA to sign it and send in?

If you got a post card from Mooney I’d fill it out and return it, this puts you in their records as being compliant.

I can’t see any reason to not return the card, if they want an A&P then they should say that I’d hope.

[Pinecone]

Traditional wheel weights are hardened with antimony and a tiny bit of tin.

The stick on ones used with alloy wheels are pretty much pure lead.

And then to totally screw you up, the make zinc clip on weights.  They are larger for the same weight.  Luckily zinc melts at a higher temperature and is less dense.  So if you control your temperature to stay below the zinc melting point, the zinc ones float to the top where you can scoop them off.  Along with the steel clips.

If you screw up and melt a zinc one in your pot of lead, you will screw it up for most uses.

[Fly Boomer]

5 hours ago, A64Pilot said:

For the iron rusting rivets use a rust stop as a primer, it stops it from coming back. Cleaning and priming it will eventually come back.

I found some kind of electronic rust inhibitor at https://www.ruststop.net/

but I expected to see some kind of coating.  Were you referring to the electronic module?

[A64Pilot]

15 minutes ago, Fly Boomer said:

I found some kind of electronic rust inhibitor at https://www.ruststop.net/

but I expected to see some kind of coating.  Were you referring to the electronic module?

No the widely available rust stoppers available most anywhere, they convert the iron oxide I believe to iron phosphate, the complete conversion of all iron oxide is how I think they work, but I’m no chemist.

Any hardware store https://en.wikipedia.org/wiki/Rust_converter

Crop dusters are completely 4130 like old fabric airplanes, the metal skins aren’t structural and are removable, a good operator washes those chemicals off their airplane every day, and at the tubing clusters you would get rust as it’s really hard to get in there and get it all. I learned from there that an application of rust convertor followed by an hour or so later brushed on paint and it wouldn’t reoccur. it comes in many applications, spray etc. I get a little bottle, just a few ounces and pour some of it into a small cup and brush it on. I don’t know but I’ve been told not to dip the brush into the bottle over and over because you can start a chemical reaction that over time reduces what’s in the bottles effectiveness, I don’t know if that’s true or not, so I don’t.

It’s a primer, but you would want to paint it anyway because it turns the rust black, very black.

This is one of many

https://www.acehardware.com/departments/home-and-decor/cleaning-and-disinfectants/rust-removers/10009?store=09042&gclid=CjwKCAjwkaSaBhA4EiwALBgQaKWHC32bovWZnEiH_n6blACcWG2hWcNCKGlUgfXNlGZBa5Iuqnm7rxoCeYwQAvD_BwE&gclsrc=aw.ds

[Igor_U]

17 hours ago, N201MKTurbo said:

I got an email from LASAR today saying they could fix this problem. The ad had a picture of a Cessna on it.

Got the same email and found that funny. 

I spoke to LASAR parts before that and iron rivets are nowhere to be found so I am not sure how would they fix it.

[N201MKTurbo]

7 minutes ago, Igor_U said:

Got the same email and found that funny. 

I spoke to LASAR parts before that and iron rivets are nowhere to be found so I am not sure how would they fix it.

I would just use the nut and bolt hardware from the newer design.

I would hope the follow on SB would address that.

I was wondering if LASAR wants you to fly your airplane there so they can inspect it and tell you it's grounded.

[Igor_U]

Just now, N201MKTurbo said:

I would just use the nut and bolt hardware from the newer design.

I would hope the follow on SB would address that.

Ritch,

I don't think so. as per IPC, 1968 M20F uses also 3 iron rivets with solid weight.

From what I saw, newer design has 6 screws per side (as opposed to 3 long rivets) that tap into helicoids installed into the weight. There's actually SB M20-335 that describes this and is applicable for Acclaims and Ovations.

and, btw, early M20F weights do not look the same as later M20J ones, possibly even later M20F. 

[A64Pilot]

40 minutes ago, Igor_U said:

 

I spoke to LASAR parts before that and iron rivets are nowhere to be found so I am not sure how would they fix it.

I would assume screws, I’d use proper length with a self locking nut on the other side, or as was said helicoil the weight.

Appearance if the form fit and function are the same isn’t important in my opinion, of course the weight has to be perfect. If I were a guessing man, I’d guess the new style dimpled skins are heavier and therefore require a heavier weight, but build quicker as there are no ribs. 

[Kelpro999]

On 10/10/2022 at 9:32 AM, DCarlton said:

A bit of a tangent, but how are the weights attached?   They look like big steel rivets.  Mine have a tad of corrosion so I’m assuming steel.  Wondering how those get squeezed or pounded.  I don’t think I saw the fasteners in the parts manual.  

Yea, they are Iron rivets. I bought them thru Genuine aircraft hardware and I remember the box said broom handle rivets.

Edited October 14, 2022 by Kelpro999
Name correction

[Kelpro999]

On 10/12/2022 at 3:56 AM, JimB said:

Just out of curiosity, how many Mooneys are out there that have the smooth skin elevators? Mine is beaded and when I google pictures the vast majority look like they are beaded. 

I have smooth on my early ’62C. 

[Sheriff23]

On 10/14/2022 at 6:44 PM, Kelpro999 said:

Yea, they are Iron rivets. I bought them thru Genuine aircraft hardware and I remember the box said broom handle rivets.

Curious when you got the rivets and how the install went?  My weights are hybrid and in bad shape.  I found some solid weights, but I am still searching for rivets and guidance for my A&P on install.

[Kelpro999]

1 hour ago, Sheriff23 said:

Curious when you got the rivets and how the install went?  My weights are hybrid and in bad shape.  I found some solid weights, but I am still searching for rivets and guidance for my A&P on install.

About a year ago when balancing surfaces. Used 1” steel plate on my driveway as the anvil and a universal head rivet set for an OE profile. Also had lead bar and 2024-t3 sheet to practice on. Remember having to start the “set” through some stiff foam to keep the #10 washer tight against the aluminum sheet. It came out close to original. I suggest checking balance since mine were significantly over under-balance range per serial number. 
 I think you can get 3/16 flat head iron rivets on eBay of any length longer than required then trim to fit. They are advised as iron or plain steel. I did apply primer before install just to satisfy some ocd. 

[rbridges]

On 10/9/2022 at 3:26 PM, M20Doc said:

It’s too bad that the trades in general aren’t viewed better.  Even a billionaire computer designer needs a lowly plumber willing to stick his hand in his toilet.

I think that's going to change in the midst of the financial aid fiasco.  Many people with trade school education are making better than those with college degrees and without the crazy debt.

 

[EricJ]

3 hours ago, Sheriff23 said:

Curious when you got the rivets and how the install went?  My weights are hybrid and in bad shape.  I found some solid weights, but I am still searching for rivets and guidance for my A&P on install.

Talk to Mooney or Maxwells.   I think they're both on top of the process for these.    Mooney had replacement weights that screwed in for the J model, so I suspect a similar fastening method may be available.   My airplane has one that is screwed in and one that is riveted.    I think I saw somewhere that they may have had helicoils or something in them, but I don't know for certain.

[Sheriff23]

I’ve spoken with both. Mooney says they’re close to sending out a solution.

I’m sourcing replacement solid weights, but Mooney says install is it authorized until they publish an engineering solution.

Hopefully it’s out soon.


Sent from my iPhone using Tapatalk

[A64Pilot]

21 hours ago, rbridges said:

I think that's going to change in the midst of the financial aid fiasco.  Many people with trade school education are making better than those with college degrees and without the crazy debt.

 

It’s been that way for a few years, often if you talk to the girl waiting your table you find out she has a Poly-Sci or some kind of Psychology or maybe Art or similar degree. I find it interesting that many degrees about the only job is teaching the degree.

When we start forgiving Student Debt we perpetuate the problem. My Wife has been an educator for a long time, pretty quickly you figure out education isn’t about education, it’s about perpetuating the system, ensuring educators are employed etc. I believe that why if you go to an A&P school why you have to take a foreign language and maybe poetry or art appreciation etc to fill the electives. Otherwise the Poetry or Art teacher is waiting tables

Not all A&P schools are like this of course, but I know one that was, and believe it or not but it was the FAA that put a stop to it, apparently the FAA has to approve the classes and Georgia hadn’t run the new schedule by the FAA, and the FAA came down with a healthy fine which returned things to normal.