MY experience with m20m rudder trim

[pkofman]

When im flying striaght and level in my  m20m  Bravo . I use a lot of rudder trim, you push that button and you feel the plane really change its position as the ball centres. 

But what i find weird is that at times after i trim the  the plane , i find it will fly wing low on one side or the other and that is with the ball centred   after using the trim

At first i thought it was a fuel imbalance thing but i really am careful to change tanks every 30 minutes to balance things.. 

I also had the mechaics check the rigging but all seems correct.

Maybe this is normal but im not sure.

Flying is a funny thing, i have probably been flying like this for a long time , never noticed ,and now for some reason im hyper   aware  of this odd tilting feeling i get when it seems everything is centered perfectly

 

Thoughts...peter

[LANCECASPER]

54 minutes ago, pkofman said:

When im flying striaght and level in my  m20m  Bravo . I use a lot of rudder trim, you push that button and you feel the plane really change its position as the ball centres. 

But what i find weird is that at times after i trim the  the plane , i find it will fly wing low on one side or the other and that is with the ball centred   after using the trim

At first i thought it was a fuel imbalance thing but i really am careful to change tanks every 30 minutes to balance things.. 

I also had the mechaics check the rigging but all seems correct.

Maybe this is normal but im not sure.

Flying is a funny thing, i have probably been flying like this for a long time , never noticed ,and now for some reason im hyper   aware  of this odd tilting feeling i get when it seems everything is centered perfectly

 

Thoughts...peter

What does the rudder trim indicator show when you are straight and level and the ball is centered? Is it centered?

[Andy95W]

Where do you get the highest speed?  That's probably the only thing that really matters.

[carusoam]

Something seems a bit out of trim...

1) For T/O and climb the rudder trim should be to the right... using the indicator for the initial setting.

2) in level flight... trim indicator near center...using the ball to set the rudder trim.

3) In descent... rudder trim a bit off to the left... using the ball to set the rudder trim.
 

4) With everything trimmed and the ball is centered... and the wing is low... the AI must be telling something isn’t right...

5) Holding the wings level, set the rudder trim using the ball....   hand flying should demonstrate this is the normal behavior...

6) If the plane is flying sideways using the AP... it sounds like it may have lost a signal from the AI...

7) Which AP do you have doing this to you?

PP thoughts only, may have seen this once in my O with my early KAP150 experience...

Best regards,

-a-

[Bob - S50]

Me thinks the ball may be lieing to you.

In the DC9, I did not trim the plane the way we were taught. I did not turn off the autopilot. If the plane was flying right wing low, for example, then something must be trying to make the plane turn left and the autopilot was putting in some bank to compensate. I would crank in a little right rudder trim and wait a minute to see if that was enough to fix it. If not I would crank a bit more rudder trim and wait. I would continue until the wings were level.

[StevenL757]

10 hours ago, pkofman said:

When im flying striaght and level in my  m20m  Bravo . I use a lot of rudder trim, you push that button and you feel the plane really change its position as the ball centres. 

But what i find weird is that at times after i trim the  the plane , i find it will fly wing low on one side or the other and that is with the ball centred   after using the trim

At first i thought it was a fuel imbalance thing but i really am careful to change tanks every 30 minutes to balance things.. 

I also had the mechaics check the rigging but all seems correct.

Maybe this is normal but im not sure.

Flying is a funny thing, i have probably been flying like this for a long time , never noticed ,and now for some reason im hyper   aware  of this odd tilting feeling i get when it seems everything is centered perfectly

Thoughts...peter

Couple of thoughts/questions...

• What - if anything - changed recently...when did you notice this?
• When you say "the mechanic checked rigging"...did he/she actually put the rigging tools on the airframe and perform a proper flight control rigging?

Steve

[pkofman]

Honestly i dont  think anything has changed..what im looking of  here is to get others experience so i know what is to be expected. My plane should be generally  no different that any other m20m . Ive been flying this plane for 3 year. i dont even know why im mentioning this . Perhpas this is how its always been and im not just hyper senstivie to any minor change as i get to know the plane better.   But i always learn on this site

as for the mechanic. I do have my rigging checked at annual to make things are as they should be. 

Peter

 

 

[hypertech]

I had a similar complaint going into this years annual.  They found the turn coordinator off a little bit and the rudder trim a little out of rig.  It was always applying a little right rudder even when full left.  The MSC got it aligned properly and now full left is a little bit left.  First, and easiest thing to do, would be to level the plane and make sure the turn coordinator is actually level.

[LANCECASPER]

11 hours ago, pkofman said:

When im flying striaght and level in my  m20m  Bravo . I use a lot of rudder trim, you push that button and you feel the plane really change its position as the ball centres. 

But what i find weird is that at times after i trim the  the plane , i find it will fly wing low on one side or the other and that is with the ball centred   after using the trim

At first i thought it was a fuel imbalance thing but i really am careful to change tanks every 30 minutes to balance things.. 

I also had the mechaics check the rigging but all seems correct.

Maybe this is normal but im not sure.

Flying is a funny thing, i have probably been flying like this for a long time , never noticed ,and now for some reason im hyper   aware  of this odd tilting feeling i get when it seems everything is centered perfectly

 

Thoughts...peter

Listen to your instincts - you find that weird. I would too. Something is not right if the ball is centered and one wing is dropped. What is your Rudder Trim indicator (green LEDs) showing when the ball is centered at cruise? Is it showing significantly right or left of cente?

Maybe it's as simple as aligning your Attitude Indicator to your autopilot.

[pkofman]

Just now, LANCECASPER said:

Listen to your instincts - you find that weird. I would too. Something is not right if the ball is centered and one wing is dropped. What is your Rudder Trim indicator (green LEDs) showing when the ball is centered at cruise? Is it showing significantly right or left of cente?

Maybe it's as simple as aligning your Attitude Indicator to your autopilot.

Maybe a dumb question but would uneven fuel loading cause this problem. is that even a factor.. 

[LANCECASPER]

Just now, pkofman said:

Maybe a dumb question but would uneven fuel loading cause this problem. is that even a factor.. 

Maybe somewhat, if there was a big difference from one side to the other, especially if you are flying alone and the side with the most fuel was the left side.

[Bob - S50]

38 minutes ago, pkofman said:

Maybe a dumb question but would uneven fuel loading cause this problem. is that even a factor.. 

An uneven fuel load might require a bit of aileron to keep the wings level but should not require bank to maintain a heading.

[Danb]

I don’t notice this phenomenon. I’d try to change positions on the trim to until it flies straight and level and not what the indicator depicts. If you could get it to fly s and l, hands off then I’d think the indicator is fibbing to you.

[Davidv]

@pkofman I find that something similar occurs in my plane and I just move the ball slightly until I'm straight and level or the wings stop their gentle rock when AP is engaged.  I've found that there is a good deal of relative room for the ball to move in the "center".  Even though I think that the plane is coordinated it usually takes slightly more left rudder to get everything perfect.  Maybe this is because our planes are flying at a very flat angle once in cruise and "planed out".

[bradp]

Does it map to a particular side (right or left wing down) or involve both?

 

[okent]

I'm new to the forum to learn about Mooneys so this may be a dumb question.  Does the Mooney have aileron trim?

I fly a CTLS and set up that scenario with aileron trim and rudder trim to fly a half a ball out and push fuel to the less full tank.(both tanks feed simultaneously and no valve to switch tanks)

After 10 minutes or so I correct the trim to level and check the sight tubes.

[LANCECASPER]

30 minutes ago, okent said:

Does the Mooney have aileron trim?

No, but people have added it

http://aerotriminc.com/

[okent]

I guess it could be the ailerons out of rigging just a bit

[carusoam]

Welcome aboard okent.

Mooneys have all kinds of adjustments.... when needed...

airleron trim is not a typical in flight adjustment...

As far as balancing fuel levels go... we have a fuel valve for that... burn the fuel out of the heavy side first...  

 

For those with an AP... the AP relieves the pilot’s tiredness that comes with holding a wing up... finger tip pressure is all it takes...

 

For the ultimate hands-off flying... there is an electric rudder trim... center the ball... let the AP handle the heavy wing...

 

If you really want to spend some money... the new Big G APs can come with anti-yaw controls...

 

Most often, I climb above the bumps into smooth air... and cruise for hours... no bumps... no need for yaw control...

 

Rudder trim is really cool... for precision differences in speed during the climb and descent...

For Best cost control... many people prefer the all manual Mooneys... and have their feet do the yaw control....  

PP thoughts only, not a CFI...

Best regards,

-a-

[rcwagner]

I got my M20J back from an annual after they made adjustments to my control surfaces.  They said they were out of tolerance.  I think they ran out of work.  

It was quite obvious when I picked it up, that it would not fly straight and level anymore.  If I let go of the yoke, it would immediately go into a left bank and the ball wasn't centered when I kept wings level.  I made a simple inclinometer, using a piece of plexiglass with an aluminum pendulum.  I found the elevators two to three degrees off from one another and the flaps about 4 degrees off from one another.  Made adjustments to set them equal while in my hangar (tires inflated the same).  It now flies hands off and the ball stays centered.  A huge improvement!  

[Davidv]

1 hour ago, rcwagner said:

I got my M20J back from an annual after they made adjustments to my control surfaces.  They said they were out of tolerance.  I think they ran out of work.  

It was quite obvious when I picked it up, that it would not fly straight and level anymore.  If I let go of the yoke, it would immediately go into a left bank and the ball wasn't centered when I kept wings level.  I made a simple inclinometer, using a piece of plexiglass with an aluminum pendulum.  I found the elevators two to three degrees off from one another and the flaps about 4 degrees off from one another.  Made adjustments to set them equal while in my hangar (tires inflated the same).  It now flies hands off and the ball stays centered.  A huge improvement!  

So you’re going to send an invoice to your shop for the work done? Just be fair and give a reasonable rate...

[rcwagner]

No, I just tell everyone I know that Western Aviation in Spokane, Washington is not a place to get work done on your airplane, either avionics or mechanical service.  They have had a huge turnover in personnel in the past year or so, and in my opinion don't have a clue how to work on a Mooney.  They are not a Mooney Service Center.  My airplane got stuck there due to the annual being due when they took 5 months to install a new audio panel, transponder, and autopilot.  The original plan was that they would have it for 3 to 4 weeks. I figure they costed me about $10,000 more that it should have.