Stabilizer Trim Alert

[gsxrpilot]

I found if using full flaps in my C, it landed best with full up trim. I find it the same in my K. Of course I'm a bit more than standard FAA sized.


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[cnoe]

(one thing that I really appreciate is the visual indicator of both trim and flap positions on a Mooney)

There are visual indicators for trim and flaps on my Mooney?

Other than setting trim prior to takeoff I don't recall ever looking at either. I just trim to relieve pressure on the yoke, and half-flaps is a count of one-two-three.

I like Cliffy's method cited above.

[cliffy]

I'm curious what speed your C trimmed out to when you had full flaps and full up trim?

Also, will your K trim full up without going too slow?

Would you have to hold down elevator (push the wheel) in order to avoid going too slow and possibly stalling in that trim condition?

i'm wondering also if the trim system was properly rigged for the correct stabilizer angles at full up and down settings. 

I'm  not exactly small myself (6 2 and 260) and i have no problems with trimming for correct speed on final and a hand pull for flare. 

My big concern is having to account for the full up trim condition on a go around if needed.

Not saying its the only way to fly but it has worked for 54 years for me.

[Bob_Belville]

2 hours ago, cliffy said:

I'm not quite sure what is meant by "trim nose high during landing"?

I always trim for correct speed on short final and just hand flare for landing. 

Have done it that way in everything I've  ever from from Cubs to 757s. 

I'd say it another way with the same outcome. We trim out the elevator pressure. With full flaps the vintage Mooneys, at least, that means near full up trim. That's to arrive at the aim point at about 1.2 Vso. 

[Western Flyer]

My wife and I have flown a J model Mooney for years and recently acquired a K model  She has a difficult time pulling the yoke back with enough force during the flare, so she trims just a bit more nose up trim than needed while stabilized on final approach, requiring less pull force in the final flare. We often fly with just the two of us in the plane, and never reached the stop in the J, but we do in the K. And after about our third or fourth flight in the K, I could not get the trim unstuck from the full-nose-up position while trying to set trim for takeoff. The owner of my local Mooney service center said that this is a somewhat common occurrence. I pulled the belly panel directly under the trim wheel and freed the jack screw using pliers. It took quite a bit of force to break it free. He inspected and lubed the jack screw and recommended trimming manually when getting near the stop, to avoid jamming it using the electric trim. 

[N201MKTurbo]

17 minutes ago, Western Flyer said:

My wife and I have flown a J model Mooney for years and recently acquired a K model  She has a difficult time pulling the yoke back with enough force during the flare, so she trims just a bit more nose up trim than needed while stabilized on final approach, requiring less pull force in the final flare. We often fly with just the two of us in the plane, and never reached the stop in the J, but we do in the K. And after about our third or fourth flight in the K, I could not get the trim unstuck from the full-nose-up position while trying to set trim for takeoff. The owner of my local Mooney service center said that this is a somewhat common occurrence. I pulled the belly panel directly under the trim wheel and freed the jack screw using pliers. It took quite a bit of force to break it free. He inspected and lubed the jack screw and recommended trimming manually when getting near the stop, to avoid jamming it using the electric trim. 

You should do M20-88. It changes the ends of the indicator screw so it doesn't jam.

http://www.mooneypilots.com/service/M20_325_88A.pdf

 

[Fly By]

This is a known serious issue very common with K's especially.  Lubrication is a very temporary "fix" and has resulted in some not-so-good outcomes.  SB M20 325 88A is a permanent fix.

[carusoam]

15 hours ago, Western Flyer said:

My wife and I have flown a J model Mooney for years and recently acquired a K model  She has a difficult time pulling the yoke back with enough force during the flare, so she trims just a bit more nose up trim than needed while stabilized on final approach, requiring less pull force in the final flare. We often fly with just the two of us in the plane, and never reached the stop in the J, but we do in the K. And after about our third or fourth flight in the K, I could not get the trim unstuck from the full-nose-up position while trying to set trim for takeoff. The owner of my local Mooney service center said that this is a somewhat common occurrence. I pulled the belly panel directly under the trim wheel and freed the jack screw using pliers. It took quite a bit of force to break it free. He inspected and lubed the jack screw and recommended trimming manually when getting near the stop, to avoid jamming it using the electric trim. 

Follow the guidance above...

Sticking trim in the full up position can be a killer problem...

Especially, if your arms aren’t that strong...
 

There are a few things from the trim system that can be balanced,  the plane’s weight and balance may be needing adjustment... for personal taste...

Basic engineering rule of thumb... don’t let powered equipment go to the end... it will jam.  Something dads teach their young drivers...

trim the last few turns by hand... always monitor the trim wheel when trimming near the end... by putting one hand on it... If you get to the end, always back it off...

But remember... go arounds are a challenge, full power, full flaps, and full up stuck trim... the only thing you will be able to do is start taking power out...
 

For some insight on strength vs. M20K vs will to survive a stuck trim situation... check in with @Amelia she has a great experience that may be helpful to be aware of...

PP thoughts only, not a CFI or physical trainer...
 

Best regards,

-a-

[Amelia]

I will let you in on a secret: If you are thinking ahead, have your MSC or Mooney-knowledgeable mechanic comply with the Mooney trim service bulletin fix for that unfortunately jammable old M20K jack screw. I don’t remember the number anymore, but it is out there. And it is important. The inexplicably subtle Mooney advice was upgraded some four years ago from a service letter that wasn’t widely disseminated.  But thanks to my misadventure and a very persistent Mooniac friend who showed up at the scene of my poor landing, Mooney was encouraged to pay attention. That valued and well-connected new friend also took me for a ride in my next Mooney a year and a half later, and hit the full nose-up trim when he had me otherwise distracted. And demonstrated the perfectly controllable, even so, slow-flight configuration. So, get the kit from Mooney and install it. Meanwhile, if it sticks and you can’t unjam it, fly real slow. Easier on your right-seater, for sure!

[skyrioca]

I am a new Mooney owner M20K model I noticed two times that my electric trim was getting stuck on nose up position after landing , one of the time was during a touch and go, after I realized that I was unable use my electric trim, I had basically to decrease power and deal with the yoke pushing nose down until trim with the wheel trim which was also stuck. It was a bit scare since I have only 10 hours in a Mooney, the CFII that I am training with was asking to keep the power up without knowing what was happening. everything happened too fast, I was trying to tell him and fly the airplane at the same time. This just happened last week

[skyrioca]

https://cdn2.hubspot.net/hubfs/4147179/M20_88A.pdf

[PT20J]

Note that this fix applies to earlier M20Js as well. It's a bigger issue in the Ks because they tend to often need full nose up trim. But every airplane should be retrofitted because the original stop design was essentially a jam nut.

Skip

[carusoam]

It is good to have... a “very persistent Mooniac friend“!

It is amazing how they can right an otherwise un-fun situation...

 

1) Be aware of powered mechanical things That have stops...

2) When a device comes to the end and hits the stop... it is possible for the electric motor to push so hard something has to give...

3) Things can bend, break, or get stuck...

4)At the end, you may also find that there is some old grease that has turned into rocks over time... Rocks aren’t very helpful when they jam the works...

5) Avoid driving mechanical things to the stops...  Not good for power steering in a car either... The car at least let’s out a whimper first... 
 

6) Go arounds are tough as it is... add in being new to a plane, and a jammed control... the term dicey comes to mind...

Skyrioca, you are working with a great instructor... does he have a lot of Mooney time?

PP thoughts only,  thanks to @Amelia for filling in the extra details...  Marvin K. M. lives in spirit! 

Best regards,

-a-