76 M20C rigging

[Guest]

3 hours ago, carusoam said:

Bill,

You are going to find….

That a small amount of research around here will help you find the things that are best for you…

Everyone is different…

When it comes to maintenance… it is the people inside the shop that are important… not the name on the outside of the shop…

Sometimes the name of the shop is the same as the people inside…

If your favorite MSC, has a presence here… you are probably in good shape…

If your favorite MSC avoids social media… it is more difficult to get to know their capabilities….

There are a few MSCs that stop by often… and one that lends a hand nearly every day…. 

Oddly, the best MSC has the name Tri-city on the outside, and Clarence on the inside…

 

There are also many experienced Mooney mechanics that have Mooney or MSC experience… in their résumé.

It comes down to finding the right people for the job…

 

Imagine needing an…

1) oil change

2) annual

3) replacing wing parts

4) Rigging… a few specific tools, plenty of Mooney experience… chance of getting it right without these, slim….

 

Some things warrant getting the best experience possible…

Best regards,

-a-

Thanks for the kind words!  I come here to learn as much as to help others(hopefully) I’m glad to participate.

Clarence

[Jim Peace]

4 hours ago, BillYesIAm said:

I always assumed that if it was an MSC then there would be at least one very experienced person with Mooneys.

Nope, not even close. 

[PT20J]

1 hour ago, M20Doc said:

Thanks for the kind words!  I come here to learn as much as to help others(hopefully) I’m glad to participate.

Clarence

What are the requirements to attain and maintain listing as a MSC?

[PT20J]

I’m curious, what others might measure for the difference in distance from the wingtips to the hangar floor and the stabilizer tips to the hangar floor with the aircraft leveled laterally. I never thought to measure it before, but did today. On my 1994 M20J, the right wingtip is 1/2 inch higher than the left and the left stabilizer is 5/8 inch higher than the right (measured at the tooling hole near the leading edge with trim set for takeoff, i.e., elevator aligned with stabilizer).

Skip

[N201MKTurbo]

7 minutes ago, PT20J said:

I’m curious, what others might measure for the difference in distance from the wingtips to the hangar floor and the stabilizer tips to the hangar floor with the aircraft leveled laterally. I never thought to measure it before, but did today. On my 1994 M20J, the right wingtip is 1/2 inch higher than the left and the left stabilizer is 5/8 inch higher than the right (measured at the tooling hole near the leading edge with trim set for takeoff, i.e., elevator aligned with stabilizer).

Skip

How do you know how flat the hangar floor is? Did you put the level on the horizontal stabilizer after leveling the plane? The 5/8 inch would be obvious with a 6’ level.

[carusoam]

Expect the floor to not be close to level…

and thickness of the slab to vary with how well the screeting was done…

Wet concrete has the innate ability to vary thickness in smooth waves that can be challenging to see without a laser….

Precision floors start with precision screeting (spreading the wet stuff) then grinding the finished dry stuff…

Steps often done for manufacturing floors… to aid in precision alignment of machinery….

 

Compare to a home garage floor that gets screeted using a 2X4…. By hand.

See what you can find out using a low cost laser…. (?)

-a-

[PT20J]

52 minutes ago, N201MKTurbo said:

How do you know how flat the hangar floor is? Did you put the level on the horizontal stabilizer after leveling the plane? The 5/8 inch would be obvious with a 6’ level.

It’s a valid point, and I have no idea. I’ll take the level next time I go and also repeat the measurement in another location. I just thought it would be interesting to see what others measure. Not claiming it’s precise, but if they all come out slightly left side high it would be interesting.

[carusoam]

Odd rubber donut wear, flattening, squeezing….

Will lift a wing or let one sag…

Probably pretty measurable out at the wing tip….

How well do our donuts flatten evenly?

We might be about to find out…. 
 

Pics of donut stacks around here have shown the height of the donuts change measurably….

But how evenly, do they sag, will make a difference in wing tip to ground measurement…

 

PP thoughts only,

-a-

[0TreeLemur]

On 12/18/2021 at 6:30 PM, PT20J said:

Shoptalk - rigging.pdf 79.55 kB · 25 downloads

Skip- great info.  Thanks for posting!

FAQ NO BRAINER (if we had one- a FAQ section, because we got plenty of brains in MS)

Fred

[0TreeLemur]

23 hours ago, PilotCoyote said:

And remember, a Mooney won’t fly level hands off for very long, even after it is rigged properly!

Anybody know why?   I can think of some possible reasons-  Not enough dihedral?  Too much interaction between fuselage and wing?  C.G. moment around roll axis?  Anyone aware anything written on this topic?   Just curious...

[David Lloyd]

Time spent in a Cherokee 140, M20C, F33A and RV7, none would fly hands off very long unless there was a little rudder nudging involved.  Mooney is the best of those four.  Maybe Cezznas are better for hands off?

[PT20J]

My 1994 M20J will fly level hands off for 10-20 seconds with both tanks full. It is pretty sensitive to fuel imbalance, however.

All airplanes have a directional-lateral coupling. You can make it roll off less by increasing dihedral, but then you get Dutch roll. Generally Dutch roll is considered more bothersome, and spiral divergence is easily controlled, so most airplanes are designed that way. The Mooney has interconnect springs between the rudder an ailerons that increase the effective dihedral. This was likely added to meet the requirement to lift a wing with rudder input. The B-25 originally had too much dihedral and couldn't meet the Army's requirement to keep wings level during skidding turns necessary for alignment on a bomb run using the Norden bombsight (at least that's one version of the story) so after the first few were built the dihedral was decreased outboard of the engines.

Skip

[0TreeLemur]

21 hours ago, PT20J said:

My 1994 M20J will fly level hands off for 10-20 seconds with both tanks full. It is pretty sensitive to fuel imbalance, however.

While some find the PC system annoying, I find it promotes rock solid roll stability, really helpful in reducing workload especially in turbulence.   Plus I think it is  ridiculously clever in terms of design.  While on a big lap around the Rocky Mountain West in 2018 after buying our C, what was a small seep in the left fuel tank suddenly developed into a 3 gallon per night gusher.  For the rest of that trip I filled up just before departure, and ran the left tank dry before switching to the right.  With the PC system doing its job, I didn't notice the imbalance despite being in the most unbalanced flight condition. 

[Jim Peace]

On 12/19/2021 at 10:06 PM, PT20J said:

What are the requirements to attain and maintain listing as a MSC?

probably none.....

[PT20J]

2 hours ago, Jim Peace said:

probably none.....

Kind of looking that way. I’ve asked several times and never seem get an answer. I think the value to the airplane owner of a shop being a MSC is nil. The quality and reputation of the shop is much more important.

Skip

[BillYesIAm]

On 12/18/2021 at 8:19 PM, Andy95W said:

That’s an easy one.  AGL Aviation in Morgantown, NC.  Lynn Mace and his wife run an excellent shop.  Lots of folks around here will vouch for them.  Schedule a day with them, they’ll get your M20C right.

https://aglaviation.com/agl-home

 

Rigging problem resolved!

Thanks to Andy and others who pointed me in the direction of AGL Aviation At Foothills Regional Airport in Morganton North Carolina. I flew up there yesterday and flew back as a happy camper. Lynn and Nathan knew exactly what to do. My ailerons were wrong, my elevators were at different angles, my rudder was not adjusted properly, my turn coordinator was off, and my flap and trim gauge was reading incorrectly. They went to work on it and by the time they were done I had a different airplane. Lynn went up with me to test everything at the end. I have had this plane for 15 years and the flight controls had never been adjusted. I should have done this years ago. It flies straighter, holds altitude better, and it is ten knots faster (NOT exaggerating.) For the first time ever I am getting indicated airspeeds that the POH says I should get. Can’t say enough good things about these guys! Thank you to them and thank you to you guys for sending me over there.

[AGL Aviation]

Rigging problem resolved!
Thanks to Andy and others who pointed me in the direction of AGL Aviation At Foothills Regional Airport in Morganton North Carolina. I flew up there yesterday and flew back as a happy camper. Lynn and Nathan knew exactly what to do. My ailerons were wrong, my elevators were at different angles, my rudder was not adjusted properly, my turn coordinator was off, and my flap and trim gauge was reading incorrectly. They went to work on it and by the time they were done I had a different airplane. Lynn went up with me to test everything at the end. I have had this plane for 15 years and the flight controls had never been adjusted. I should have done this years ago. It flies straighter, holds altitude better, and it is ten knots faster (NOT exaggerating.) For the first time ever I am getting indicated airspeeds that the POH says I should get. Can’t say enough good things about these guys! Thank you to them and thank you to you guys for sending me over there.

Bill you’re MOST welcome. Anytime you need anything, give us a shout!


Sent from my iPhone using Tapatalk

[Yetti]

On 12/19/2021 at 10:19 PM, PT20J said:

It’s a valid point, and I have no idea. I’ll take the level next time I go and also repeat the measurement in another location. I just thought it would be interesting to see what others measure. Not claiming it’s precise, but if they all come out slightly left side high it would be interesting.

When you look straight on a Mooney.   It always looks like the Port gear leg is bent in a bit.   I don't think the gear is square.... or plumb.

[EricJ]

55 minutes ago, Yetti said:

When you look straight on a Mooney.   It always looks like the Port gear leg is bent in a bit.   I don't think the gear is square.... or plumb.

Don Maxwell told me that's an optical illusion.   

[carusoam]

On 1/5/2022 at 4:19 PM, BillYesIAm said:

Rigging problem resolved!

Thanks to Andy and others who pointed me in the direction of AGL Aviation At Foothills Regional Airport in Morganton North Carolina. I flew up there yesterday and flew back as a happy camper. Lynn and Nathan knew exactly what to do. My ailerons were wrong, my elevators were at different angles, my rudder was not adjusted properly, my turn coordinator was off, and my flap and trim gauge was reading incorrectly. They went to work on it and by the time they were done I had a different airplane. Lynn went up with me to test everything at the end. I have had this plane for 15 years and the flight controls had never been adjusted. I should have done this years ago. It flies straighter, holds altitude better, and it is ten knots faster (NOT exaggerating.) For the first time ever I am getting indicated airspeeds that the POH says I should get. Can’t say enough good things about these guys! Thank you to them and thank you to you guys for sending me over there.

Bill,

That is the best post covering the challenges of control rigging… and a great pirep for AGL!

+2 for Lynn and Tamara!

-a-

[JoeM]

suggestions for an experienced Mooney mechanic to rig my 65 M20E in Southern CA?