Electric Flaps Troubleshooting

[Marauder]

I’m hoping I can assess without taking the belly skin off. But, I think it’s inevitable. The way it’s moving, leads me to believe it’s some sort of disconnect like that. 
Both flaps still move (with manual pressure) in sync, so they’re attached. The fact that the flaps dropped after landing makes me think it “jarred” down when the wheels touched. 

To get access to the flap mechanism you will need to remove the belly panel that sits in between the flaps. Little bit of a pain, with lots of screws.


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[GDGR]

Can’t be worse than taking the lower cowl off to get at a starter

Edited January 13, 2019 by GLJA

[Yetti]

3 hours ago, GLJA said:

I’m hoping I can assess without taking the belly skin off. But, I think it’s inevitable. The way it’s moving, leads me to believe it’s some sort of disconnect like that. 

Both flaps still move (with manual pressure) in sync, so they’re attached. The fact that the flaps dropped after landing makes me think it “jarred” down when the wheels touched. 

Try running them all the way down and then see if they come back up.   Gently wiggle the flap and see if that works.   if so clean the limit switches with contact cleaner.

[GDGR]

2 minutes ago, Yetti said:

Try running them all the way down and then see if they come back up.   Gently wiggle the flap and see if that works.   if so clean the limit switches with contact cleaner.

They don’t move with the switch. Once in the ground, engine off, I tried the switch. I could hear the motor engaging, with no movement. There’s zero resistance until it hits their current position  

If you step out, you can lift the flap. Once you let go, it drops back to the position they are in (roughly 20 deg flap).

 

[Yetti]

Well that certainly seems more expensive than a $2.00 can of contact cleaner.   I believe that is a side window motor off a car.  There is a plastic material that degrades in the round part off the motor..   On Ford trucks, I used to pull the broken stuff out and fill them back with polyester resin and cut up fiberglass cloth.   I think they were designed break and not crush your little brother's head in the window.

Edited January 13, 2019 by Yetti

[N201MKTurbo]

13 hours ago, Yetti said:

Well that certainly seems more expensive than a $2.00 can of contact cleaner.   I believe that is a side window motor off a car.  There is a plastic material that degrades in the round part off the motor..   On Ford trucks, I used to pull the broken stuff out and fill them back with polyester resin and cut up fiberglass cloth.   I think they were designed break and not crush your little brother's head in the window.

It is made by Commercial Aircraft Products. It is the same flap actuator used on a lot of Cessnas. It is an aircraft part not a repurposed auto part.

You will see a rubber coupler between the motor and gearbox. it is the most likely culprit if the motor is running but the flaps are not moving.

[GDGR]

22 minutes ago, N201MKTurbo said:

It is made by Commercial Aircraft Products. It is the same flap actuator used on a lot of Cessnas. It is an aircraft part not a repurposed auto part.

You will see a rubber coupler between the motor and gearbox. it is the most likely culprit if the motor is running but the flaps are not moving.

Is it a replacement part? I’m headed to the hangar after lunch to figure it out. Really don’t want this plane sitting for another month for one small rubber part. 

[carusoam]

Also look for both square blocks to be there...

They appear to be the up and down limits... for this system...

They also appear to be held in place with a single set screw...

For all parts mounted on Mooneys... the fine folks, including Dan at @LASAR can help with replacements...

PP thoughts only, I have not seen this system up close at all...

Best regards,

-a-

[GDGR]

Result was actuator spun off the motor. The 40 year old grease was not allowing for smooth travel. 

My guess is it finally seized, and the actuator removed itself. 

1.25 hours of removing belly pan, cleaning grease, and reattaching and it works great. 

Thanks to everyone for the suggestions 

 

Edited January 14, 2019 by GLJA

[Guest]

1 hour ago, GLJA said:

Result was actuator spun off the motor. The 40 year old grease was not allowing for smooth travel. 

My guess is it finally seized, and the actuator removed itself. 

1.25 hours of removing belly pan, cleaning grease, and reattaching and it works great. 

Thanks to everyone for the suggestions 

Did you remove the mounting end cap and clean and repack the gear box as well?

Clarence

[carusoam]

Now that you know how the old grease turns to rocks.... over the decades...

Get a good gander at the tail trim while you are in there... 

They have a similar screw and grease...

PP thoughts only, not a mechanic of any sort...

Best regards,

-a-

[GDGR]

21 minutes ago, M20Doc said:

Did you remove the mounting end cap and clean and repack the gear box as well?

Clarence

Didn’t repack the gear box. But, annual is in March. I’ll definitely put it on the list to my AME. 

[anthonydesmet]

Resurrecting this thread due to flap issue this past weekend......

 

Left Illinois Saturday to return to home base in Florida.  Flap extension and retraction during pre-flight worked normally.  Flaps on takeoff and retraction airborne worked normally.  Used half flaps on landing for high winds and wind gusts.  During rollout hit the flap switch to bring them up (and assumed they did) until post flight walk around and noticed flaps still in half position.  Turned master back on and cycled switch - no joy and could not here any sign of motor running or engaging...just dead.  Cycled flaps circuit breaker and switch again and no joy moving up or down. Physically put pressure with my hands on flaps to see if there was any play pushing up or down but felt normal to pre-flight.

I didn't try to force anything and have not had time to go back to hanger and start playing with limit switches but plan to this weekend.  Before I do I wanted to get thoughts from the group to help focus my efforts this weekend.

limit switches?, flap switch?, motor?

Model: 1980 M20K

switch - normal 1980 J/K switch on console next to cowl flaps.

[GDGR]

16 minutes ago, anthonydesmet said:

Resurrecting this thread due to flap issue this past weekend......

 

Left Illinois Saturday to return to home base in Florida.  Flap extension and retraction during pre-flight worked normally.  Flaps on takeoff and retraction airborne worked normally.  Used half flaps on landing for high winds and wind gusts.  During rollout hit the flap switch to bring them up (and assumed they did) until post flight walk around and noticed flaps still in half position.  Turned master back on and cycled switch - no joy and could not here any sign of motor running or engaging...just dead.  Cycled flaps circuit breaker and switch again and no joy moving up or down. Physically put pressure with my hands on flaps to see if there was any play pushing up or down but felt normal to pre-flight.

I didn't try to force anything and have not had time to go back to hanger and start playing with limit switches but plan to this weekend.  Before I do I wanted to get thoughts from the group to help focus my efforts this weekend.

limit switches?, flap switch?, motor?

Model: 1980 M20K

switch - normal 1980 J/K switch on console next to cowl flaps.

In my F, I could hear the flap motor engage. I’d either assume wiring, or the motor is kaput. 

Remove the belly skin, check connectivity at the motor. If you have power there, it’s the motor. If you don’t, it’s a wiring issue you’ll have to chase. 

[elehman3]

I am not trying to resurrect an old topic. 

My daughter "acquired" a 1975 M20K.  Two weekends ago her and her instructor made a 4+ hour round trip so she could get her hours in "her" plane.  Her mentor, Rick, noticed that the flight took longer then planned, and they were not achieving proper air speed.  Once they touched down at the airport she uses and hangers her plane they did their walk around and noticed that the flaps were still in 15.  So they flew it to where her Rick's hanger is here in Temple.  Rick and his mechanic looked it over.  They removed the panel to the flaps motor and cleaned all the switches as stated in this thread. 

I went by the next day to see if I could help.  I am not an electronics engineer, but do have some skills of working around pinball machines, arcade machines, 70's-90's computers, and model railroading. I've always been fascinated with many things electronic. I have been scouring the internet (GTSing (Googleing That Stuff)) about this issue with her plane for days. That is what led me to finding this thread, and group. 

I did find the wiring diagram that is posed above, but it is not 100% readable. 

We did take the connections off the relays and switches and cleaned them with CRC, and fine sandpaper.  Rick also has been on the net looking things up, and he does have some access to service manuals, etc.  He was able to find the part numbers for the relays and I was able to get a diagram of the relays.  They are DPDT 12v 25A.  After removing one, Rick did take it apart and found that there was a lot of corrosion in and around the coil.  Using his "connections" he was able to get 2 replacement relays.  They got them installed this weekend, but the issue continues.  Like everyone above has said they will go full and retract, 15 but no retract, etc.  

So what my questions are, is there any "newer (modern)" replacement parts for the relays and the micro switches?  And what are our next steps?  Is there a way I can get a better wiring diagram of the flap controls and the flap motor controls?

Using the data sheet for the relays I did find TP96P7D22-12 as a possible replacement for the relay and are about $25 each.

Also from this post I did find the V3L-3 microswitches on a few electronic vender sites.  Digikey and Mouser both carry the microswitches, but at $160 each, I want to make sure that this is where the issues are.

Thank y'all for the help.

Tex-Hogger

 

[LANCECASPER]

1 hour ago, elehman3 said:

I am not trying to resurrect an old topic. 

My daughter "acquired" a 1975 M20K.  Two weekends ago her and her instructor made a 4+ hour round trip so she could get her hours in "her" plane.  Her mentor, Rick, noticed that the flight took longer then planned, and they were not achieving proper air speed.  Once they touched down at the airport she uses and hangers her plane they did their walk around and noticed that the flaps were still in 15.  So they flew it to where her Rick's hanger is here in Temple.  Rick and his mechanic looked it over.  They removed the panel to the flaps motor and cleaned all the switches as stated in this thread. 

I went by the next day to see if I could help.  I am not an electronics engineer, but do have some skills of working around pinball machines, arcade machines, 70's-90's computers, and model railroading. I've always been fascinated with many things electronic. I have been scouring the internet (GTSing (Googleing That Stuff)) about this issue with her plane for days. That is what led me to finding this thread, and group. 

I did find the wiring diagram that is posed above, but it is not 100% readable. 

We did take the connections off the relays and switches and cleaned them with CRC, and fine sandpaper.  Rick also has been on the net looking things up, and he does have some access to service manuals, etc.  He was able to find the part numbers for the relays and I was able to get a diagram of the relays.  They are DPDT 12v 25A.  After removing one, Rick did take it apart and found that there was a lot of corrosion in and around the coil.  Using his "connections" he was able to get 2 replacement relays.  They got them installed this weekend, but the issue continues.  Like everyone above has said they will go full and retract, 15 but no retract, etc.  

So what my questions are, is there any "newer (modern)" replacement parts for the relays and the micro switches?  And what are our next steps?  Is there a way I can get a better wiring diagram of the flap controls and the flap motor controls?

Using the data sheet for the relays I did find TP96P7D22-12 as a possible replacement for the relay and are about $25 each.

Also from this post I did find the V3L-3 microswitches on a few electronic vender sites.  Digikey and Mouser both carry the microswitches, but at $160 each, I want to make sure that this is where the issues are.

Thank y'all for the help.

Tex-Hogger

 

It is very unlikely that she has a 1975 M20K, since they weren't introduced as a 1979 model in late 1978. (https://books.google.com/books?id=S8rkR5Hozv8C&printsec=frontcover#v=onepage&q&f=false)

If the relays aren't the issue, the next step might be the limit switches. But rather than just throw parts at it, if you're in Temple, TX you might call Don Maxwell (Longview TX) or Brian Kendrick (San Marcos TX) and let them know what you've done and see where they would go next. If they will agree to look at it then you can also get an A&P logbook sign-off which you'll need anyway since you're past what owner preventive maintenance allows.

[elehman3]

1 hour ago, LANCECASPER said:

It is very unlikely that she has a 1975 M20K, since they weren't introduced as a 1979 model in late 1978. (https://books.google.com/books?id=S8rkR5Hozv8C&printsec=frontcover#v=onepage&q&f=false)

If the relays aren't the issue, the next step might be the limit switches. But rather than just throw parts at it, if you're in Temple, TX you might call Don Maxwell (Longview TX) or Brian Kendrick (San Marcos TX) and let them know what you've done and see where they would go next. If they will agree to look at it then you can also get an A&P logbook sign-off which you'll need anyway since you're past what owner preventive maintenance allows.

Thanks for the update.  I wasn't exactly sure what year or make.  I've only been around it once, and didn't get to look thru the paperwork on it.  My dad is the one who "helped" her acquire it.  I'm here to help in what way I can, and let the A&P and them do the work.  I am just trying to find how and what would need to help them and point them in the right direction.  Like you said, I just don't want to start to throw parts at it, and really figure out where the issue is.

I get it, it's a 50 year old plane, with 60's technology.  Just like some of the EM pinball machines I've been around, there is just that one part that causes the issue, and sometimes it just takes moving the right wire to find that bug.

Now that I did a little more research it is actually a 1975 M20F.

 

[PT20J]

Most likely, it’s a later model K since it has the relays and the three position flap switch with the 15 deg. position. Since the relays have been replaced, it must be a switch causing the problem.  Within the box that contains the relays are two microswitches that control the 15 deg position. The schematics can be found in service and maintenance manual. Someone posted this simplified version a while back.

Flap switch logic.pdf

[Justin Schmidt]

I would like to point out something that I don't think as been mentioned,  take a look at the barrel connector,  behind pilot side panel. In my 75 F the connector was corroded, causing that behavior with an additional issue of power shorts. Connectors need to be inspected every so often as well

[elehman3]

11 hours ago, Justin Schmidt said:

I would like to point out something that I don't think as been mentioned,  take a look at the barrel connector,  behind pilot side panel. In my 75 F the connector was corroded, causing that behavior with an additional issue of power shorts. Connectors need to be inspected every so often as well

Will do.  Thanks.  I think this "may" be the issue.  They are going to look at the connectors to the flap switch, and follow the wiring to the connector(s) and clean them next.