Mooney Elevator AD

[Shadrach]

On 1/28/2023 at 10:05 AM, RobertGary1 said:

Why was the F included? Are there any smooth skin F elevators?

All Fs had smooth control surfaces prior to 1970 (IIRC).  The “beaded” control surfaces of the later models are less expensive and easier to make.

[Gary0747]

On 1/27/2023 at 10:13 PM, PT20J said:

neodymium magnet

Lots of discussion on finding the exact magnet that the SB specifies.  My view is any magnet will attach to a good non corroded hybrid weight because the steel tube will be intact.  But the corrosion product of the steel tube will likely be very weakly attracted to a magnet if at all.  I hope the factory tested this on some bad weights before specifying this magnet.   I see no downside to using the strongest magnet you can find.  

[Guest]

Be thankful the FAA didn’t want it X-ray’d.

[lamont337]

Hybrid or nah? Doesn’t seem to have the inner cylinder like pictured in the SB.

 

[takair]

23 minutes ago, lamont337 said:

Hybrid or nah? Doesn’t seem to have the inner cylinder like pictured in the SB.

 

I think this is where the magnet comes into play to confirm. 

[Gary0747]

35 minutes ago, lamont337 said:

Hybrid or nah? Doesn’t seem to have the inner cylinder like pictured in the SB.

It does have micro cracks and chips.  

[Hector]

Printed the SB yesterday and went to the airport. There was an AP/IA working on a plane next to my hangar so walked over and asked him if he could do the inspection. He was familiar with the SB and already had it in his iPad. I have a C model and already knew I did not have a hybrid weight because I had already inspected it myself. The AP came over, visually inspected the weights and used a pick up tool with a magnet to verify. He then signed off my logbook and the inspection sheet for the factory. It all took maybe 15 minutes.


Sent from my iPad using Tapatalk Pro

[Gary0747]

2 hours ago, M20Doc said:

Be thankful the FAA didn’t want it X-ray’d.

 If Mooney had included X-ray in the SB it would have likely been in the AD.  Since it seems the FAA has taken everything in the SB as the right answer with no opportunity for discussion or input via a NPR.  Is this a new approach or have they done it this way much in the past except on Emergency ADs?.   I recall even the Piper wing spar AD had opportunity for comment, some delay on inspections and some reasonable changes on how to implement?

[EricJ]

3 hours ago, M20Doc said:

Be thankful the FAA didn’t want it X-ray’d.

If it weren't lead that may have been a go-to inspection method. 

Not gonna see much through that lead.   I don't know if an eddy current inspection even works on that (shhh...I shouldn't give them ideas, it's not past the comment period yet).

[EricJ]

15 hours ago, Gary0747 said:

I have not been able to find the referenced section X1, but it sounds like they are telling us to chemically “strip a corrosion sensitive” part?    This appears to be ignoring the later guidance in M20J Service and Maintenance Manual section 20-00-02 on Corrosion Detection and Prevention.  They are looking for microscopic cracks which must be a new standard for condemning counter weights.   From my knowledge of corrosion and as indicated in the M20J manual you should not get solvents into cracks and locations where they are hard to either neutralize or wash out.  Using a stripping solvent with a chlorinated hydrocarbon component has damaged a number of aircraft in the past too.  They don’t say that directly but I have seen this and have a background dealing with this type of corrosion.    
In any case these hybrid corrosion sensitive weights were likely manufactured with microscopic seam cracks between the steel tube and the lead.  You can see this area in my previous posting of photos of two hybrid weights that had been in service for 55 years.   I was asking if anybody knew why one was still in perfect shape and one was totally destroyed to see if anybody understood the mechanisms at work here.  Nobody answered so here is what I think based on my background.  The round seam on the side is a microscopic crack that if not adequately sealed will allow water and contaminates and paint stripper in when exposed to that.   The liquids essentially become electrolytes allowing a galvanic cell and the resulting corrosion.  The key here is you can have dissimilar metals in contact but if you eliminate the electrolyte there will be no corrosion.  You can see in the photo the good weight has had paint and a sealant covering the crack between the steel and the lead.  The airplane also has been well maintained and kept in a good dry environment.  It has not been tied down near the ocean which can be an extreme hazard for galvanic corrosion over time.  I believe the hybrid weights are a risky design that obviously fail much easier if not properly maintained.  But I think the hybrid weights can last indefinitely if the side seams are kept sealed.  I know this thinking is contrary to some who think all hybrid weights are a ticking time bomb.  But I don’t think they have an adequate understanding on the mechanisms at play here.   Bottom line in my opinion if the factory is calling for a chemical strip of the corrosion sensitive weights that would be a mistake which is likely to cause new galvanic  corrosion.    Haven’t we normally just scraped select locations with a knife probing for corrosion?  That would be adequate in my mind plus negate the need for removing and balancing the elevator.

End of My Rant

The C-G model SMM that I have doesn't have a section XI, and the SB just says to strip it, so a method suitable for lead and corrosion concerns would be acceptable imho.   For lead that's probably scraping as you suggest, so scraping it followed by picking or something suitable on the steel insert should be fine.   I think the idea is just to get it bare so that you can inspect for cracks in the material rather than cracks in the paint.

The rebalancing requirement seems to be a bit of a stretch, too, since the weight isn't being removed for the inspection.   I'm guessing somebody is concerned about the difference in weight between the previous paint and the repaint after the inspection?   Or maybe that it's lost weight due to corrosion?

My personal view is that this AD, and perhaps the SB, aren't the best examples of how to deal with an issue.   There is no provision in the AD for a Special Flight Permit, which has the potential to cause some serious issues for people after Feb. 13th, and I don't see a rationale for it.

[MikeOH]

Below is a picture of my weight; doesn’t look anything like the hybrid weight. In fact, I don’t see how the hybrid weight could even be installed on my non-smooth elevator!

Reading the AD it appears ONLY the M20F had these hybrid weights, but the FAA is, I guess, worried that they may have been put on other models?

Does anyone know if the hybrid weights can even be installed on other than smooth elevators?

 

[Guest]

8 hours ago, EricJ said:

If it weren't lead that may have been a go-to inspection method. 

Not gonna see much through that lead.   I don't know if an eddy current inspection even works on that (shhh...I shouldn't give them ideas, it's not past the comment period yet).

Should I put X-ray in the comments section for the AD?

[Ragsf15e]

32 minutes ago, M20Doc said:

Should I put X-ray in the comments section for the AD?

Great, now the Canadians are “helping” us make our AD “better”!

[Guest]

Just now, Ragsf15e said:

Great, now the Canadians are “helping” us make our AD “better”!

Always trying to help out.  With X-ray no hybrid weights will be found making everyone happier.

[Vance Harral]

4 hours ago, MikeOH said:

Reading the AD it appears ONLY the M20F had these hybrid weights, but the FAA is, I guess, worried that they may have been put on other models?

Does anyone know if the hybrid weights can even be installed on other than smooth elevators?

Correct, Mooney/the FAA is worried elevators from the affected models may have been installed on other airplanes.  Dunno if hybrid weights can be installed on beaded-skin elevators, but I wonder if anyone ever replaced a damaged beaded-skin elevator with a salvaged smooth-skin elevator, via 337 (or just not asking questions they don't want answers to).

Our airplane - like yours - has the beaded skin elevators, not smooth.  But I'm going to have a friendly A&P sign off an AD inspection anyway.  Given the weasel words in the associated SB, I just don't want to get into an argument with some future buyer or IA who thinks the AD inspection should have been performed.  Easier to just point to the logbook entry and say, "Yes, this airplane has been inspected in accordance with that AD".

[MikeOH]

4 minutes ago, Vance Harral said:

Correct, Mooney/the FAA is worried elevators from the affected models may have been installed on other airplanes.  Dunno if hybrid weights can be installed on beaded-skin elevators, but I wonder if anyone ever replaced a damaged beaded-skin elevator with a salvaged smooth-skin elevator, via 337 (or just not asking questions they don't want answers to).

Our airplane - like yours - has the beaded skin elevators, not smooth.  But I'm going to have a friendly A&P sign off an AD inspection anyway.  Given the weasel words in the associated SB, I just don't want to get into an argument with some future buyer or IA who thinks the AD inspection should have been performed.  Easier to just point to the logbook entry and say, "Yes, this airplane has been inspected in accordance with that AD".

@Vance Harral

I don't know about your aircraft, but mine's serial number is well after the upper limit shown in the Applicability section of the AD.  As the photo I provided shows, I have a beaded elevator and the weight looks nothing like the hybrid.  Today I moved a neodymium magnet all over the weight without attraction.   Am I wrong to conclude I do NOT need an official signed by an A&P entry in my logbook?  There are many other ADs not applicable to my aircraft by virtue of serial number that have no logbook entry.  Why would this AD be any different?

[EricJ]

24 minutes ago, MikeOH said:

@Vance Harral

I don't know about your aircraft, but mine's serial number is well after the upper limit shown in the Applicability section of the AD.  As the photo I provided shows, I have a beaded elevator and the weight looks nothing like the hybrid.  Today I moved a neodymium magnet all over the weight without attraction.   Am I wrong to conclude I do NOT need an official signed by an A&P entry in my logbook?  There are many other ADs not applicable to my aircraft by virtue of serial number that have no logbook entry.  Why would this AD be any different?

It's not.   If it doesn't apply to your airplane by virtue of S/N then it doesn't apply just like if it were a Piper or Cessna or an M20K.   The AD list that your IA maintains would be a good place to record that it was noted but not applicable by S/N.   Putting it in the logbook doesn't hurt, either, but you don't need to ground after Feb 13th to wait for that.

[Guest]

28 minutes ago, MikeOH said:

@Vance Harral

I don't know about your aircraft, but mine's serial number is well after the upper limit shown in the Applicability section of the AD.  As the photo I provided shows, I have a beaded elevator and the weight looks nothing like the hybrid.  Today I moved a neodymium magnet all over the weight without attraction.   Am I wrong to conclude I do NOT need an official signed by an A&P entry in my logbook?  There are many other ADs not applicable to my aircraft by virtue of serial number that have no logbook entry.  Why would this AD be any different?

That would be my interpretation as well.  At next annual making an entry saying the AD is not applicable due to serial number.

[Vance Harral]

To be clear, I wouldn't balk at buying an airplane whose logs simply say this A/D is not applicable by serial number, and I doubt many others would either.  In our case, though, our A&P is coming out anyway to inspect the overhauled fuel pump we're installing, so it's kind of a no-brainer to have him take a quick look and note in the logbook that the airplane was inspected for bad elevator counterweights as well.  You could do that at your next annual if you choose and it probably wouldn't cost you anything extra.  I'd feel differently about asking an A&P to perform a formal inspection if doing so required disassembling anything, but it doesn't in this case - a quick look is sufficient.

As an example of what I'm getting at, though... would you feel comfortable buying my airplane if you reviewed its logs and saw the electric landing gear actuator had never been disassembled and inspected for worn gears?  None of SB M20-190B or AD 75-04-09 or AD 75-23-04 apply to our airplane, because neither its serial number nor the ITT LA11C2114 actuator installed in it are on any of the callout lists in those documents.  If you ask around though, most Mooney-savvy shops and owners would tell you it would be foolish not to at least occasionally inspect the actuator, and that you should be skeptical of buying an airplane that's never had the inspection done.  If anyone is going to perform that inspection, you should probably have them log it, whether the AD is truly applicable or not.  My attitude toward this new elevator counterweight AD is similar.

[Gary0747]

One added difficult step in doing the elevator removal for the 100 hour inspection for anyone with good hybrid weights is if you have the Laser hinge gap seals mod.  Each hinge seal has four rivets to remove and replace every time the inspection is done!   Yes the smart thing to do is just replace the weights and do the removal only once but no weights are currently available new or used so grounding the airplane may be the only realistic option!

[RobertGary1]

16 hours ago, MikeOH said:

Below is a picture of my weight; doesn’t look anything like the hybrid weight. In fact, I don’t see how the hybrid weight could even be installed on my non-smooth elevator!

Reading the AD it appears ONLY the M20F had these hybrid weights, but the FAA is, I guess, worried that they may have been put on other models?

Does anyone know if the hybrid weights can even be installed on other than smooth elevators?

 

Your elevator is beaded not smooth. So you wouldn’t have those weights. 

[MikeOH]

28 minutes ago, RobertGary1 said:

Your elevator is beaded not smooth. So you wouldn’t have those weights. 

While that certainly appears to be the case, the AD, rather surprisingly IMHO, does NOT use that criteria in the Applicability section.  The beaded vs. smooth elevators discussion is only in the Background section of the AD.

Lucky for me, the AD is NOT applicable to my plane as it’s outside the applicable SN range stated in the AD.

[Yourpilotincommand]

Dumb question.. can this AD be signed off in my logbook as not applicable by an A&P or does it require an IA signature?  I don’t have the hybrid weight. 

[mooniac15u]

On 1/29/2023 at 8:55 AM, lamont337 said:

Hybrid or nah? Doesn’t seem to have the inner cylinder like pictured in the SB.

 

Those round areas look like they could be filler and paint over a hybrid weight.

[Fly Boomer]

29 minutes ago, Yourpilotincommand said:

Dumb question.. can this AD be signed off in my logbook as not applicable by an A&P or does it require an IA signature?  I don’t have the hybrid weight. 

In my limited experience, ADs that don't apply are not usually called out specifically in the logs.  I have only seen them on a list from one of the services used by many (most?) mechanics, with the "resolution" noted as "N/A due to s/n", "N/A due to m/n", "N/A due to not installed", etc.  As someone above pointed out, we don't usually mention ADs for Cessnas or Pipers, so why put something in your log that may apply to an M20C even though you fly an M20V?