Mooney Elevator AD

[Kelpro999]

15 minutes ago, Gary0747 said:

The other thing that may cause the 540 M20Fs made prior to 1968 to require different balance setting is the bunges are different as well as the elevators.  So if changing elevators pre 68 to post 68 is ever needed the bunges will likely need changing also.

Changing parts from one to another shouldn’t be difficult as long as fit, form and function is maintained along with total mass and balance data meeting the same as removed parts. When not the same, the part is not correct and must be altered to meet or not used.

[Flyman2456]

Has anyone recieved an update about the parts kit (M20-345-001) for this yet? I ordered back in Jan when this was released and have been down since. 

[Gary0747]

19 hours ago, Kelpro999 said:

From reading above the difference between -1 and-7 is approximately 1lb. 
 That’s a significant difference. 

Yes that has bothered a lot me since I have been flying my M20F for over 30 years and well over 2,000 hours and some times near VNE with no sign of flutter.  So why would I want to change the balance of the elevator by this large amount?  I can only hope that there is more than one correct answer to the flutter prevention scenario.  

I do recall a post by a knowledgeable contributor (PT20J) in September that said the following which I hope is true:

“Most control surfaces are overbalanced (i.e., leading edge heavy) to control flutter. With the control surface CG ahead of the hinge line, a deflection of the control surface causes a correcting hinge moment that tends to dampen out motions caused by aerodynamic forces.

Evidently the Mooney control system is stiff enough that flutter is not an issue and so the control surfaces are underbalanced (i.e., trailing edge heavy) most likely for improving handling qualities. The Mooney ailerons have fairly heavy control forces due to their short span, wide chord design and the elevator forces are a bit high due to the springs and bobweights. Underbalancing would tend to reduce the initial hinge moment when a surface is deflected. But, that's just a guess; to know for certain the designer's intent you'd have to ask Al. “

Skip

 

[Kelpro999]

18 minutes ago, Gary0747 said:

Yes that has bothered a lot me since I have been flying my M20F for over 30 years and well over 2,000 hours and some times near VNE with no sign of flutter.  So why would I want to change the balance of the elevator by this large amount?  I can only hope that there is more than one correct answer to the flutter prevention scenario.  

I do recall a post by a knowledgeable contributor (PT20J) in September that said the following which I hope is true:

 

“Most control surfaces are overbalanced (i.e., leading edge heavy) to control flutter. With the control surface CG ahead of the hinge line, a deflection of the control surface causes a correcting hinge moment that tends to dampen out motions caused by aerodynamic forces.

Evidently the Mooney control system is stiff enough that flutter is not an issue and so the control surfaces are underbalanced (i.e., trailing edge heavy) most likely for improving handling qualities. The Mooney ailerons have fairly heavy control forces due to their short span, wide chord design and the elevator forces are a bit high due to the springs and bobweights. Underbalancing would tend to reduce the initial hinge moment when a surface is deflected. But, that's just a guess; to know for certain the designer's intent you'd have to ask Al. “

Skip

 

Now we need a pirep before & after part/spec change preferably at or near VNE+0

[ShuRugal]

9 hours ago, Kelpro999 said:

Now we need a pirep before & after part/spec change preferably at or near VNE+0

Someone call Elliot.

[Hank]

10 hours ago, Kelpro999 said:

Now we need a pirep before & after part/spec change preferably at or near VNE+0

I'll do it! Throw me your keys, and hold my beer!    

[Igor_U]

On 2/22/2023 at 8:49 AM, Kelpro999 said:

Now we need a pirep before & after part/spec change preferably at or near VNE+0

I should be flying this afternoon to test it and lubricate the engine. Perhaps late lunch at Jeffco. I completed the install last week but lately,  WX was really crappy around here...

 

13 hours ago, Hank said:

I'll do it! Throw me your keys, and hold my beer!    

Beer is in the fridge for after the flight. you are welcome to join but might need faster bird to come on time. 

[Mooneycrazy]

Im just tryint to catch up with all of you on this. I have a 1966 M20F and one of my counterweights is visibly corroded. So....where do we purchase the replacement counterweight? I tried contacting LASER and I never hear back from them...

 

[Kelpro999]

6 minutes ago, Mooneycrazy said:

Im just tryint to catch up with all of you on this. I have a 1966 M20F and one of my counterweights is visibly corroded. So....where do we purchase the replacement counterweight? I tried contacting LASER and I never hear back from them...

 

Contact any MSC or support@mooney.com

[Kelpro999]

2 minutes ago, Kelpro999 said:

Contact any MSC or support@mooney.com

Do you know if it’s surface corrosion or a hybrid weight issue?

[romeotango]

Dugosh in Kerrville is responsive.

[hammdo]

Maxwells — they discovered the issue initially…

-Don

[A64Pilot]

Not that I’ve seen a whole bunch of flight controls, but I’ve not seen any that were leading edge heavy, (overbalanced) the few that I’ve balanced you installed the flight control into a jig or sometimes a home fabricated method of it being supported by the hinge centerline, level and measuring the weight at the trailing edge at a specified spot, but there was always weight. (underbalanced) Often bolts sitting on a knife edge is all it takes to support the flight control for balancing.

However I do know that the lighter the flight control is at the trailing edge, the higher the airspeed before flutter becomes an issue.

There are limits of course, but I balance towards the lightest trailing edge that I can and within allowable limits, this is safest, plus as the aircraft ages, from spot painting or repairs or just dirt or insect nests or whatever in the flight control, they over time move towards trailing edge heavy. I’ve never seen one gain weight on the leading edge as there is a lot less surface area there.

‘Unless the center of gravity of the weight is different, you’re going to end up with the same weight, regardless of how heavy it started with if your changing weights, if it was in balance to start with.

Personally I’d like it to be too heavy than too light, it’s a whole lot easier removing some weight than it is to add weight.

Note, I’ve never balanced a Mooney flight control but can’t see how it’s any different.

If I were the King, I’d ship weights that were too heavy, making life easy on the mechanics.

[A64Pilot]

On 2/22/2023 at 11:49 AM, Kelpro999 said:

Now we need a pirep before & after part/spec change preferably at or near VNE+0

Velocity dive or VD is the test point and from memory it’s 120% of VNE.

That number may vary with type and Category of aircraft, I’m not sure.

I know your jesting, but you really shouldn’t exceed VNE

[Kelpro999]

18 hours ago, A64Pilot said:

Velocity dive or VD is the test point and from memory it’s 120% of VNE.

That number may vary with type and Category of aircraft, I’m not sure.

I know your jesting, but you really shouldn’t exceed VNE

I wouldn’t advise anyone pass VNE. plus our birds are near 60 years old. 

[A64Pilot]

8 minutes ago, Kelpro999 said:

I wouldn’t advise anyone pass VNE. plus our birds are near 60 years old. 

VNE can be many things other than flutter, it could be for instance when the windshield fails and blows into your face, but yes the words never exceed, should mean, well never exceed.

But not all limits are actually limits, like max demonstrated crosswind for example, often it means the max cross wind experienced during Certification, but it’s no necessarily a limit, it could be though.

Some airplanes VNE is tough to reach, much less exceed, but I remember on my first Solo cross country in the M20AT, in the Cessna 152’s and Cherokee’s I had flow the technique was to stay at full throttle, but to trim in a 500 FPM rate of descent at the proper time to reach pattern altitude a couple of miles from the airport, reducing throttle to keep the MP you began the descent with.

So I did that with the M20AT and when I noticed I was all over VNE, so it’s apparently not hard to exceed VNE in a Mooney, without the noise and vibration you got in say the 152.

[Gary0747]

Anybody have info on the status of new weights from Mooney?

[67 m20F chump]

I talked to Frank at Mooney and he said they had the weights at the factory and were doing QC checks then shipping them out.  That was early this week 1/27/23.  

[Gary0747]

On 3/2/2023 at 9:05 AM, 67 m20F chump said:

I talked to Frank at Mooney and he said they had the weights at the factory and were doing QC checks then shipping them out.  That was early this week 1/27/23.  

Apparently this QC check is called a “Conformity Check” and it is done by the FAA?  I have never heard of this on previously manufactured and installed parts like this 40016-7 weight?  If true we may have a longer wait given all the Continental AD stuff on the FAA plate now?  

[Flyman2456]

On 3/2/2023 at 10:05 AM, 67 m20F chump said:

I talked to Frank at Mooney and he said they had the weights at the factory and were doing QC checks then shipping them out.  That was early this week 1/27/23.  

The MSC still hasn't received them. Do you know if they sent them out yet?

[67 m20F chump]

Frank said they had to sand blast and prime the rivets before they would ship.  That as the last I heard and I don't know if they shipped.  I’m getting worried about having the part in time for my annual now.

[67 m20F chump]

I hear they have shipped some out.  Some good news!

[Dmax]

New Style Counter Weights for AD 2023-02-04 are now available from any Mooney Service Center. Kit Pn.# M20-345-001

[MikeOH]

1 hour ago, Dmax said:

New Style Counter Weights for AD 2023-02-04 are now available from any Mooney Service Center. Kit Pn.# M20-345-001

Price?

[Pinecone]

12 hours ago, MikeOH said:

Price?

If you have to ask.............