Mooney Elevator AD

[Kelpro999]

Does anyone know if surface balance specification data is provided for all affected elevators for each aircraft? Another question is why is elevator removal required even if weight replacement is? I haven’t seen the AD, only the SB and it looks like a bunch of data gathering. It seems to me that replacement of problem part with good one of same weight would be the same as if nothing happened. If rebalancing is required, everyone affected is in for a real treat if the F is anything like my early C. 

[MikeOH]

10 hours ago, RobertGary1 said:

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

While I KNOW that, and YOU know that, it would appear the FAA does NOT know that!

I make that statement based on the FACT that the AD does NOT use beaded vs. smooth as the applicability criterion!

Thus, the reason for my last question in my post: is it even possible to install the hybrid weights on ANY beaded elevator.  THAT is the only rational scenario I can envision for the FAA NOT using beaded vs. smooth elevators as the application criterion.  Elevator type makes more sense than the by SN applicability; which isn't even logical since the suspect weights were originally ONLY installed M20Fs...yet the AD applies to M20C, D, E, and Gs!  Thus, the FAA thinks it's possible the hybrid weights may have been 'moved around' over the years; so, why would SN even have anything to do with where they ended up??? (Not that I'm complaining, since I'm off the hook based on SN)

This whole AD looks 'rushed to market' IMHO

[MikeOH]

Oh, and while my mind is running amok:  what was Mooney thinking with this 'hybrid' weight design in the first place??  At first I thought it was just a steel plug within the lead to obtain the right weight/CG, but it appears it's just a length of steel TUBING with lead both surrounding it, and on the inside!  What's the point?

[Robert67]

I just got an email today from Mooney. The replacement weights are be made now. Should being ready in about a month. Got a quote or the kit. M20-345-001  price is 751.35. Includes 2 weights, 6 iron rivets an 12 washers.  Supposed to be available towards end of February.  There will be limited quantities. Was recommended to pre order. Email from Mooney said that Mooney will be receiving them from the vendor in batches of approximately 25 kits at a time.   I think the price is very fair considering this is an aircraft part.  Thanks to Mooney for supporting our older aircraft

[Robert67]

just got an email today from Mooney. The replacement weights are being made now. Should being ready in about a month. Got a quote or the kit. M20-345-001  price is 751.35. Includes 2 weights, 6 iron rivets an 12 washers.  Supposed to be available towards end of February.  There will be limited quantities. Was recommended to pre order. Email from Mooney said that Mooney will be receiving them from the vendor in batches of approximately 25 kits at a time.   I think the price is very fair considering this is an aircraft part.  Thanks to Mooney for supporting our older aircraft

[RobertGary1]

20 hours ago, MikeOH said:

While I KNOW that, and YOU know that, it would appear the FAA does NOT know that!

I make that statement based on the FACT that the AD does NOT use beaded vs. smooth as the applicability criterion!

Thus, the reason for my last question in my post: is it even possible to install the hybrid weights on ANY beaded elevator.  THAT is the only rational scenario I can envision for the FAA NOT using beaded vs. smooth elevators as the application criterion.  Elevator type makes more sense than the by SN applicability; which isn't even logical since the suspect weights were originally ONLY installed M20Fs...yet the AD applies to M20C, D, E, and Gs!  Thus, the FAA thinks it's possible the hybrid weights may have been 'moved around' over the years; so, why would SN even have anything to do with where they ended up??? (Not that I'm complaining, since I'm off the hook based on SN)

This whole AD looks 'rushed to market' IMHO

Isn’t the serial number in the AD for the weight itself? I guess they assume someone maybe have swapped elevators. 

[Gary0747]

Trying to figure out why the balance numbers in the SB345A for the primary focus Airplane of this the M20F are different from the factory manual?  I have manual #104 dated July 1980.  The balance range in that is 20 to 22 in-lb .  Compared to the SB showing 14-16.75 in-lb?     Perhaps it was changed in a previous SB?  Or a mistake.  Not sure how to resolve?  

[MikeOH]

9 hours ago, RobertGary1 said:

Isn’t the serial number in the AD for the weight itself? I guess they assume someone maybe have swapped elevators. 

I don't believe so; from the AD: "c) Applicability
Mooney International Corporation Model M20C, M20D, M20E, M20F, and M20G airplanes, all serial numbers up to 680170 inclusive, certificated in any category."  Sure sounds like airplane SNs

Additionally, I don't think the weights are serialized.

And, yes, I think the FAA may be concerned with swapped elevators.  Thus, why the SN of the aircraft makes little sense and smooth vs. beaded would seem to be a much better applicability criterion.  BWTHDIK?

[MikeOH]

1 hour ago, Gary0747 said:

Trying to figure out why the balance numbers in the SB345A for the primary focus Airplane of this the M20F are different from the factory manual?  I have manual #104 dated July 1980.  The balance range in that is 20 to 22 in-lb .  Compared to the SB showing 17-20 in-lb?     Perhaps it was changed in a previous SB?  Or a mistake.  Not sure how to resolve?  I know somebody will say just balance it to 20 and satisfy both.  But I had to beat them to that one.

Speculation on my part but could this be related to both the SN range of the AD (680170 inclusive) and the transition from smooth to beaded?  That is, the M20F models prior to SN 680171 were fitted with the smooth elevators with the balance range in the SB, while the 1980 manual balance range is for the beaded elevators fitted to M20Fs AFTER the 680170?

[Gary0747]

3 hours ago, MikeOH said:

Speculation on my part but could this be related to both the SN range of the AD (680170 inclusive) and the transition from smooth to beaded?  That is, the M20F models prior to SN 680171 were fitted with the smooth elevators with the balance range in the SB, while the 1980 manual balance range is for the beaded elevators fitted to M20Fs AFTER the 680170?

Neither the SB or the Service Manual seem to make this distinction.  It seems like an immediate clarification is warranted so if it is a mistake and the wrong balance numbers were used there might have to be a redo and some unhappy owners.  Another reason for having a comment period and a NPR?

[A64Pilot]

I think which elevator or serial number etc is actually irrelevant as the procedure to confirm or deny is so benign, just put a magnet to it, if it sticks you have a problem, if not then you don’t.

The removal of elevators, weights etc thankfully only applies to those who the magnet sticks, and from the pictures and the testimony from Professional Maintainers if you have a hybrid weight, you really, really want this AD complied with.

I don’t believe that will be many people as I read somewhere only 130 hybrid weights were manufactured and sadly a lot of our older birds are no longer in service.

Even though not required I put a magnet to mine, because you never know for sure what’s happened in the last 40 years and it’s such a simple check. Why not?

[MikeOH]

Yeah, I spent 8 bucks at Home Depot to buy a neodymium magnet just so I could watch it fall off my elevator weight

It sure stuck to the iron rivets, though!

[Gary0747]

It appears the comment period on the AD has now been expanded to 40 days?  At least that is what is showing up on the web site now?  If it is actually changed they may want more ongoing feed back since implementing the new weights may not begin for that long?

[DCarlton]

2 hours ago, MikeOH said:

Yeah, I spent 8 bucks at Home Depot to buy a neodymium magnet just so I could watch it fall off my elevator weight

It sure stuck to the iron rivets, though!

If it's the round flat quarter sized ones, you can use those for locating nails in drywall to find studs.  Not a total waste.  :> 

[Fly Boomer]

3 hours ago, MikeOH said:

It sure stuck to the iron rivets, though!

What makes those rivets "iron".  They can't be cast iron -- too brittle.  Aren't they just a malleable steel alloy?

[MikeOH]

5 minutes ago, Fly Boomer said:

What makes those rivets "iron".  They can't be cast iron -- too brittle.  Aren't they just a malleable steel alloy?

Not a clue; thought I saw the weight attach rivets called “iron” somewhere…

Guess I should have said, “it sure stuck to those indeterminate steel alloy rivets”, instead

[EricJ]

I'm interested in whatever experience anybody has with iron rivets similar to the ones used for the weights.   They're much longer than a typical rivet and the shop head appears to flatten more than a typical rivet.   Are these installed with a typical gun with a flush hammer and a bucking bar?   Squeezer?   Hydraulic press?

[Kelpro999]

13 minutes ago, EricJ said:

I'm interested in whatever experience anybody has with iron rivets similar to the ones used for the weights.   They're much longer than a typical rivet and the shop head appears to flatten more than a typical rivet.   Are these installed with a typical gun with a flush hammer and a bucking bar?   Squeezer?   Hydraulic press?

This is what I used after cutting them down to 1.5 x dia. protrusion. Also used abnormally heavy bucking bar (1” thick steel plate approx 10”square) laying on the ground but could have been overkill. Smaller bar was bouncing back allowing the rivet head to pull away and prevent clinching. The striker used was universal head inserted into a 3/4” steel bar and initially struck through 1/4” foam rubber to prevent top washers from lifting.  The only attempt using a squeezer failed completely.

[Kelpro999]

12 minutes ago, Kelpro999 said:

This is what I used after cutting them down to 1.5 x dia. protrusion. Also used abnormally heavy bucking bar (1” thick steel plate approx 10”square) laying on the ground but could have been overkill. Smaller bar was bouncing back allowing the rivet head to pull away and prevent clinching. The striker used was universal head inserted into a 3/4” steel bar and initially struck through 1/4” foam rubber to prevent top washers from lifting.  The only attempt using a squeezer failed completely.

This is how the rudder came out, elevators the same but couldn’t find images at this time 

[takair]

1 hour ago, Kelpro999 said:

This is how the rudder came out, elevators the same but couldn’t find images at this time 

Maybe I missed it, did you rudder have composite weights?

[Kelpro999]

33 minutes ago, takair said:

Maybe I missed it, did you rudder have composite weights?

No, this was after refinishing. That’s when I discovered my early C couldn’t balance with paint. It has a lower unbalance force spec. than later models.

[Gary0747]

Iron Rivet called out in the parts manual is part number 430026-999 and found on the Lasar web site for $16.43 each.  But the SB20-345A calls out a different part number 224497 iron rivet which I am not able to search and find.  
A previous Mooney Space discussion on weight replacement before this SB is attached here.   A knowledgeable mechanic contributor makes the statement that the normal A&P mechanic will not have the ability to install the iron rivets because they should be driven red hot.  I hope this is not the case.

 

[N201MKTurbo]

4 minutes ago, Gary0747 said:

Iron Rivet called out in the parts manual is part number 430026-999 and found on the Lasar web site for $16.43 each.  But the SB20-345A calls out a different part number 224497 iron rivet which I am not able to search and find.  
A previous Mooney Space discussion on weight replacement before this SB is attached here.   A knowledgeable mechanic contributor makes the statement that the normal A&P mechanic will not have the ability to install the iron rivets because the have they should be driven red hot.  I hope this is not the case.

 

I've never set these rivets, but what would be so hard about setting them when they are red hot? Heat them with a torch, push them in and set them. You just have to be quick about it. 

It seems that @Kelpro999 set them cold.

It seems that if they were red hot they would melt the lead.

[ShuRugal]

8 minutes ago, Gary0747 said:

Iron Rivet called out in the parts manual is part number 430026-999 and found on the Lasar web site for $16.43 each.  But the SB20-345A calls out a different part number 224497 iron rivet which I am not able to search and find.  
A previous Mooney Space discussion on weight replacement before this SB is attached here.   A knowledgeable mechanic contributor makes the statement that the normal A&P mechanic will not have the ability to install the iron rivets because they should be driven red hot.  I hope this is not the case.

 

How could you drive a red hot rivet through a lead weight?  You'd ruin the weight.

[Gary0747]

I think Mooney must have learned a much easier way to install weights using threaded inserts in the lead and a screws.  All the more recent model Mooney’s were done this way.   Going this way should allow the weights to be easily removed to inspect or modify if repainting and rebalancing is needed.

part number for the threaded insert is MS51830-201L and the screw is NAS623-3-1

Both appear cheap and readily available.