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Posted

Hello, I own an M20K 231, yesterday I went flying and while I was climbing with the autopilot the place was porpoising up to about 5K and then it stopped. Altitude hold was fine and after landing in auburn, took off climbed again and not porpoising. After much research looks like I may have water in the static line ( didn't try the alternate as I didn't know at that time the problem). Perhaps the water drained or evaporated but reading the manual looks like I have a static port drain. 

I am so sorry but can someone send me a pic of where it is?  I noticed a port by the static under the tail so I am assuming that's the one and how do I drain it? 

 

thank you so much 

Posted
5 hours ago, gabez said:

Hello, I own an M20K 231, yesterday I went flying and while I was climbing with the autopilot the place was porpoising up to about 5K and then it stopped. Altitude hold was fine and after landing in auburn, took off climbed again and not porpoising. After much research looks like I may have water in the static line ( didn't try the alternate as I didn't know at that time the problem). Perhaps the water drained or evaporated but reading the manual looks like I have a static port drain. 

I am so sorry but can someone send me a pic of where it is?  I noticed a port by the static under the tail so I am assuming that's the one and how do I drain it? 

 

thank you so much 

It’s a tiny spring loaded push button.  Look for a small metal “button” barely protruding below the aircraft skin. There’s one on the left wing root for the pitot too.  Just push and it should drain.

Posted
14 hours ago, Ragsf15e said:

It’s a tiny spring loaded push button.  Look for a small metal “button” barely protruding below the aircraft skin. There’s one on the left wing root for the pitot too.  Just push and it should drain.

thanks I found it. Nothing came out when I pushed it so perhaps all the water evaporated/drained as I was flying. I will try again this weekend. 

Posted
6 hours ago, gabez said:

thanks I found it. Nothing came out when I pushed it so perhaps all the water evaporated/drained as I was flying. I will try again this weekend. 

Good luck.  Possibly it wasn’t water in there.  Occasionally silicon lube on both control shafts to make sure they are sliding through the instrument panel very smoothly could help too.  Spray on, and wipe it really clean.

Posted
7 minutes ago, Ragsf15e said:

Good luck.  Possibly it wasn’t water in there.  Occasionally silicon lube on both control shafts to make sure they are sliding through the instrument panel very smoothly could help too.  Spray on, and wipe it really clean.

thanks! is there a specific brand that I should use? 

Posted
1 hour ago, gabez said:

thanks! is there a specific brand that I should use? 

No, and there’s some debate on this.  The “eyeball joint” that the shaft slides on is touchy.  Initially mooney suggested silicone, then they said leave it dry.  Either way, you need that shaft to slide very smoothly (both pilot and copilot) or it can cause fluctuations.  After a while they will get dirty, so using silicone is mostly about cleaning them.  I wouldn’t recommend anything with oil in it as it may cause dirt to stick and eventually make it worse.  Lube it, wipe it down, make sure there’s no “sticktion”.

Good luck!

  • Like 1
Posted
1 hour ago, Ragsf15e said:

No, and there’s some debate on this.  The “eyeball joint” that the shaft slides on is touchy.  Initially mooney suggested silicone, then they said leave it dry.  Either way, you need that shaft to slide very smoothly (both pilot and copilot) or it can cause fluctuations.  After a while they will get dirty, so using silicone is mostly about cleaning them.  I wouldn’t recommend anything with oil in it as it may cause dirt to stick and eventually make it worse.  Lube it, wipe it down, make sure there’s no “sticktion”.

Good luck!

thank you so much! 

  • Like 1
Posted
46 minutes ago, gabez said:

thank you so much! 

Silicone spray on a clean shop towel, pull the yoke all the way back and wipe the chrome tube clean and dry.

Posted

The yoke shafts don't move in a linear manner. You can see this clearly if you move the elevators from full down to full up and note that the yoke moves vertically as well as fore and aft. Because of this the penetration needs to articulate. Over the years, Mooney has used several different arrangements. Starting during the J run and later models, a black Nylatron eyeball and socket is used. Spraying lubricant into the eyeball eventually gums it up causing it to become stiff. When this happens, it doesn't articulate well and binds the yoke shaft. Lubricating the shaft lightly with silicone spray sometimes helps for a while, if it's not too bad. 

Posted
21 hours ago, PT20J said:

The yoke shafts don't move in a linear manner. You can see this clearly if you move the elevators from full down to full up and note that the yoke moves vertically as well as fore and aft. Because of this the penetration needs to articulate. Over the years, Mooney has used several different arrangements. Starting during the J run and later models, a black Nylatron eyeball and socket is used. Spraying lubricant into the eyeball eventually gums it up causing it to become stiff. When this happens, it doesn't articulate well and binds the yoke shaft. Lubricating the shaft lightly with silicone spray sometimes helps for a while, if it's not too bad. 

Same thing with the j-bar slider… just keep it clean…

  • Like 1
Posted
On 3/19/2023 at 2:32 PM, Ragsf15e said:

It’s a tiny spring loaded push button.  Look for a small metal “button” barely protruding below the aircraft skin. There’s one on the left wing root for the pitot too.  Just push and it should drain.

There is also an identical drain "button" under the pilot side wing, near the fuselage, for the pitot circuit.  

  • Like 2
Posted
On 3/21/2023 at 1:56 PM, Bolter said:

There is also an identical drain "button" under the pilot side wing, near the fuselage, for the pitot circuit.  

damn really? went up yesterday all checked out fine no issues. we had a ton of rain. I pushed the button before the flight but nothing came out. The climb w/auto pilot was fine. I will check the button on the pilot side as well 

 

Thank you!!

Posted
2 minutes ago, gabez said:

damn really? went up yesterday all checked out fine no issues. we had a ton of rain. I pushed the button before the flight but nothing came out. The climb w/auto pilot was fine. I will check the button on the pilot side as well 

 

Thank you!!


very important…

Which autopilot do you have?

Cleaning controls has been reported as being very helpful for the light servos that the newest APs have….

It will help our statistics collection to know what AP you have.

Best regards,

-a-

Posted
Just now, carusoam said:


very important…

Which autopilot do you have?

Cleaning controls has been reported as being very helpful for the light servos that the newest APs have….

It will help our statistics collection to know what AP you have.

Best regards,

-a-

KFC 150

  • Like 1
Posted

For the older APs…

cleaning the control shaft is helpful…

If you get chatter when boxing out the controls pre-flight…

That is a hint the shaft isn’t moving a smoothly as it can.

Servo systems will have difficulty with the feedback that comes with that…

 

The next thing to look into… is the wear on the old servos… the elevator servo gets used a lot controlling attitude during the flight…

There are a lot of KFC servos coming out lately… you might be able to test a servo that is on the shelf locally…

 

PP thoughts only, we have a couple of good AP techs around here…

Best regards,

-a-

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