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Mooney. trim stuck innpositionn on go around


Arthur

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After 22 years of not flying I got back to it. Bought a Mooney 231 in Spring Branch. 400 hours in M20E 845 in M20K.Took my CfII along for the trip to Fort Lauderdale. Thankfully I did. Small squawk issues  on the way. IFR  half of  the way with ATC sliding us through a hole near Lakeland. Headed for a night landing in the light rain at KHWO. My CFII had been working on trying to get my landings set up a little  better by extending the downwind and getting the speeds right. We both decide on a go around for a better set up Power in trim down, but no movement on the trim. Nose up and near a stall we were both pushing with all of our strength to  hold the yoke down. He thought I was pulling when we were both pushing with as much force as we could manage. we worked out that I would try to hold the nose in an up position, but not quite stall speed. I TOOK HIM TWO HANDS TO FINALLY BREAK THE TRIM FREE. He made the landing the next time around not using the trim for speed, but power at just the right time to ease it on.

So guys when I head to the airport tomorrow to figure out what happened where do I start?

 

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Know that less power will keep the nose from bobbing up so strongly...

This is something a Mooney specific CFII should be very familiar with...

A go-around is not an emergency.  It is a well orchestrated procedure...

Your plane has plenty of power... it isn’t all needed all the time...

Also be very familiar with the effect of flaps, more and less, on attitude...

Now, you are looking for your Mooney specific maintenance professional...

The mechanical trim system is pretty simple... going from front to back cleaning out the old grease is a must...

You may find some of the old grease has turned to rocks...  you may also find interference along the trim controls... look for missing paint off the tubes...

We lost a Mooney around here before because of stuck trim... Mimi’s M20K, aka Marvin K Mooney...

there isn’t anything normal about stuck trim systems in Mooneys...  it is too  easy to run out of strength pulling back or pushing forwards against the errant trim...

Do you have an electric trim system?  Is it working properly?

Back in the day... a CFI had a similar experience on a go around... resulting in a complete loss of control...

Get ready to share some pics...

PP thoughts only, not a CFI..

Best regards,

-a-

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Glad you had another soul aboard to help muscle the trim free and you both survived! Your scenario sounds eerily similar to one that @Amelia experienced.  Hopefully she can chime in. Also the search feature can be your friend. "Amelia", "runaway trim", "trim failure", "trim", etc... Following the search result strings are each an opportunity for high velocity learning.

Edited by jonhop
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15 minutes ago, Arthur said:

After 22 years of not flying I got back to it. Bought a Mooney 231 in Spring Branch. 400 hours in M20E 845 in M20K.Took my CfII along for the trip to Fort Lauderdale. Thankfully I did. Small squawk issues  on the way. IFR  half of  the way with ATC sliding us through a hole near Lakeland. Headed for a night landing in the light rain at KHWO. My CFII had been working on trying to get my landings set up a little  better by extending the downwind and getting the speeds right. We both decide on a go around for a better set up Power in trim down, but no movement on the trim. Nose up and near a stall we were both pushing with all of our strength to  hold the yoke down. He thought I was pulling when we were both pushing with as much force as we could manage. we worked out that I would try to hold the nose in an up position, but not quite stall speed. I TOOK HIM TWO HANDS TO FINALLY BREAK THE TRIM FREE. He made the landing the next time around not using the trim for speed, but power at just the right time to ease it on.

So guys when I head to the airport tomorrow to figure out what happened where do I start?

 

The trim wheel sticking at full nose up trim is a known issue with the K's. There is a fix for it.

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Glad you had another soul aboard to help muscle the trim free and you both survived! Your scenario sounds eerily similar to one that [mention=6983]Amelia[/mention] experienced.  Hopefully she can chime in. Also the search feature can be your friend. "Amelia", "runaway trim", "trim failure", "trim", etc... Following the search result strings are each an opportunity for high velocity learning.


That’s the one I recalled!


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15 minutes ago, Arthur said:

So guys when I head to the airport tomorrow to figure out what happened where do I start?

Order the kit for Mooney Service Instruction M20-325 & M20-88A, it was introduced in 1990 I believe and fixes this issue permanently . One K model was recently totalled because of this issue. But the SI is not terribly expensive, nor hard to install and totally eliminates the chance of this happening again. You obviously needed it yesterday! You can download the SI on https://www.mooney.com/service and scroll down to support.

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37 minutes ago, Arthur said:

After 22 years of not flying I got back to it. Bought a Mooney 231 in Spring Branch. 400 hours in M20E 845 in M20K.Took my CfII along for the trip to Fort Lauderdale. Thankfully I did. Small squawk issues  on the way. IFR  half of  the way with ATC sliding us through a hole near Lakeland. Headed for a night landing in the light rain at KHWO. My CFII had been working on trying to get my landings set up a little  better by extending the downwind and getting the speeds right. We both decide on a go around for a better set up Power in trim down, but no movement on the trim. Nose up and near a stall we were both pushing with all of our strength to  hold the yoke down. He thought I was pulling when we were both pushing with as much force as we could manage. we worked out that I would try to hold the nose in an up position, but not quite stall speed. I TOOK HIM TWO HANDS TO FINALLY BREAK THE TRIM FREE. He made the landing the next time around not using the trim for speed, but power at just the right time to ease it on.

So guys when I head to the airport tomorrow to figure out what happened where do I start?

 

 

 

 

 

This is probably the one with the most answers:

https://mooneyspace.com/topic/20707-stabilizer-trim-alert/?tab=comments#comment-314055

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32 minutes ago, kortopates said:

Order the kit for Mooney Service Instruction M20-325 & M20-88A, it was introduced in 1990 I believe and fixes this issue permanently . One K model was recently totalled because of this issue. But the SI is not terribly expensive, nor hard to install and totally eliminates the chance of this happening again. You obviously needed it yesterday! You can download the SI on https://www.mooney.com/service and scroll down to support.

The old style trim stops are plain nuts on the forward trim screw (under the trim wheel) and can jam. The mod replaces them with stepped stop nuts that are jam proof. Until you get this fixed, avoid running the trim all the way to the stops.

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7 hours ago, ziggysanchez said:

The trim wheel sticking at full nose up trim is a known issue with the K's. There is a fix for it.

That’s why some folks are very adamant about not trimming in the flare. It makes a nice smooth landing but a go-around can kill. If not for the far too nose-up trim, but also that nose up trim jamming  against the stop. 

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“Now, you are looking for your Mooney specific maintenance professional...”  -CAM

 

With PJ, you have this base covered... :)

See if you can get a pic of whatever it is that isn’t working properly...

Best regards,

-a-

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On ‎4‎/‎9‎/‎2019 at 8:52 PM, kortopates said:

Order the kit for Mooney Service Instruction M20-325 & M20-88A, it was introduced in 1990 I believe and fixes this issue permanently . One K model was recently totalled because of this issue. But the SI is not terribly expensive, nor hard to install and totally eliminates the chance of this happening again. You obviously needed it yesterday! You can download the SI on https://www.mooney.com/service and scroll down to support.

I had this kit installed.  Worth every penny, completely solves the problem of sticking but... you really do need to have a plan for go around solo without the assistance of electric trim.  Those crummy BK trim switches fail from time to time and often with little to no warning.  If they give warning it is in the form of periodically not working until the microswitches finish arcing themselves to death.  I'm not exactly buff (Q: Do you even lift bruh?  A: Do pint glasses count?) and I can hold the plane level at maximum up trim at climb power long enough to use the trim wheel to crank the trim down, so it doesn't require too much strength -- maybe a little more than a pushup.  (Had this happen once with a CFI in the plane.  His comment, "That looked like a lot of work.  Glad you're doing the flying.")

Strategy to make this easier:  Start running the electric trim as soon as you choose to go around.  Make it muscle memory item 1 on go around, before adding power.  This gives you a few  advantages:

  1. Nose down trim ahead of power reduces the maximum arm power necessary to hold it at go around attitude.
  2. If your electric trim switch decides to pick that exact moment to fail, you know about it before you jam the throttle forward.
    1. Which gives you the option to feed in partial power to arrest the descent, then wheel in a few handfuls of nose down, then adjust the power again.
    2. Or if the trees look uncomfortably close, at least you know you're going to need to push hard and wheel in trim fast after applying climb power.

Additional:  Flap retraction makes the problem worse.  Take a beat or two before flipping the switch to make sure everything is working right.

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1 minute ago, johncuyle said:

Those crummy BK trim switches fail from time to time and often with little to no warning.

My BK trim switch failed a few years ago, resulting in runaway trim towards the terrafirma. I had written about it at the time, but I didn't know what was going on and nearly lost the ship. It was not obvious as it was happening, I will say that.

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My BK trim switch failed a few years ago, resulting in runaway trim towards the terrafirma. I had written about it at the time, but I didn't know what was going on and nearly lost the ship. It was not obvious as it was happening, I will say that.

I wonder if a LED connected to the trim circuit would be a useful hangar fairy project?


Tom
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the following sounds sketchy written down, however in demonstration it makes perfect sense.

 

I used to teach the G550... One scenario was a jammed elevator on rotation ( lots of UP).  The guys who crashed were the ones who tried in vein to push the nose down as the attitude continued to increase until a sharp stall and resulting nose low attitude.  The proper response was to enter a bank thus reducing your vertical lift component.  this puts you in a turn but stops the nose from getting higher.  While in the level or climbing turn turn the pilot(s) are then able to work the problem without dealing with high control forces or worrying about an exaggerated stall.   Obviously obstacles and speed are of concern, however even in a Mooney, Entering an acceptable bank for the speed will at the very least reduce the control forces needed to keep the nose down.  Clearly you do not want to go into a 45 degree bank without acceptable speed as you could enter an accelerated stall if the up trim is high enough.

Edited by Austintatious
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13 hours ago, Austintatious said:

the following sounds sketchy written down, however in demonstration it makes perfect sense.

No, that sounds exactly right. A coordinated turn is a pitching and yawing maneuver.  (A flat turn would be all yaw, a 90 deg banked turn would be all pitch. A coordinated turn is a combination of both). The g in the turn comes from the pitch rate. 

Rolling into a turn to counteract a pitch up is the counterpoise to leveling the wings to stop a spiral. 737 MAX guys would have to roll inverted first though. 

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