Flaps fail to retract on Ground (1990 J)

[DC_Brasil]

Hello, 

Wanted to know if anyone has experienced this issue.

In two out of my last 4 flights, during my departure checklists (i.e. engine ready running) I checked the full movement of the flaps. After extending to full, they will not retract. 

I had to pull the flap actuator CB, give it a minute or so, reset it, and then it works again.

They work well in flight and after landing (no issues whatsoever).

Any thoughts?

[Ragsf15e]

 

44 minutes ago, DC_Brasil said:

Hello, 

Wanted to know if anyone has experienced this issue.

In two out of my last 4 flights, during my departure checklists (i.e. engine ready running) I checked the full movement of the flaps. After extending to full, they will not retract. 

I had to pull the flap actuator CB, give it a minute or so, reset it, and then it works again.

They work well in flight and after landing (no issues whatsoever).

Any thoughts?

I had to work on mine a little while ago.  I doubt it has anything to do with the cb if it wasn’t popped.  There are two limit switches and two relays (in some models).  Both the relays and the limit switches eventually fail.  If they are sticking down, id first check the down limit switch.  Once you look at the schematic and open up the airplane to look, its not hard to figure out.  Mine wouldn’t come down all the time and the up limit switch was at fault.  A new one wasn’t expensive from online electronics sources (exact part number).

[N201MKTurbo]

With the flaps down, leave the master on with the flap switch in the up position. Get out of the plane and grab the trailing edge of the flaps and shake them up and down. They will probably come up. This will get you by until you GT new switches or clean the ones you have.

[Ragsf15e]

18 minutes ago, N201MKTurbo said:

With the flaps down, leave the master on with the flap switch in the up position. Get out of the plane and grab the trailing edge of the flaps and shake them up and down. They will probably come up. This will get you by until you GT new switches or clean the ones you have.

For sure.  When I replaced my up limit switch, it still worked ok when i bench tested it but there was a slight dead spot in its actuation that was causing it to stop retraction but not allow them back down.  I could easily see how a vibrating airplane or shaking the flaps could alleviate this.

Note though, when mine stuck up the first time I tried this and it didn’t do anything, so maybe not always going to help. Or maybe I needed to shake harder.

[DC_Brasil]

47 minutes ago, Ragsf15e said:

 

I had to work on mine a little while ago.  I doubt it has anything to do with the cb if it wasn’t popped.  There are two limit switches and two relays (in some models).  Both the relays and the limit switches eventually fail.  If they are sticking down, id first check the down limit switch.  Once you look at the schematic and open up the airplane to look, its not hard to figure out.  Mine wouldn’t come down all the time and the up limit switch was at fault.  A new one wasn’t expensive from online electronics sources (exact part number).

Thanks for sharing the pictures!

My plane is fresh out of the annual. I am guessing the flap screws must have been lubricated during the annual so the A&P should have accessed that part. That may have introduced some instability to the switch.

I will check those. Thanks!

[larryb]

My experience is that the relays are the weak link. Mooney made a few mistakes in the design of that circuit that impact reliability, at least in my 1997 Encore.

[PT20J]

When mine did that it was a relay. Mooney used a couple of different relays. The original design used socketed relays that are available and easily replaced. The “improved” design (which I’ve been told by a well known MSC is no better) uses soldered-in relays making replacement somewhat more difficult 

[Ragsf15e]

The interesting thing is that my 1987 K doesn’t have relays at all.  It’s just wired right to the limit switches.  And yes, that’s how it is in the wiring diagram too.

[PT20J]

I think the relays are only in the planes that have the takeoff position preselect. 

[Yetti]

For the limit switches go to Wally world and get the red can of "Contact Cleaner"   sometimes called "Electronics Cleaner"     Spray vigorously into the switch while exorcising them.   

While you are there clean off the jack screw and apply new grease and run it in and out a couple of times.   Probably has not been done since the plane left the factory. 

 

 

Same should work on your Stall Indicator on the wing.    May need the little red tube to get inside the box and hopefully direct at the limit switch. 

 

[tls pilot]

2 hours ago, Yetti said:

For the limit switches go to Wally world and get the red can of "Contact Cleaner"   sometimes called "Electronics Cleaner"     Spray vigorously into the switch while exorcising them.   

While you are there clean off the jack screw and apply new grease and run it in and out a couple of times.   Probably has not been done since the plane left the factory. 

 

 

Same should work on your Stall Indicator on the wing.    May need the little red tube to get inside the box and hopefully direct at the limit switch. 

 

Agree. The contact cleaner you mention is ok. But the DeoxIT 5 is a superior product. Available on Amazon.

I would hope the jack screw is greased at annual?? what access panel on a longbody gives access to the flap jackscrew?

 

[Yetti]

13 minutes ago, tls pilot said:

Agree. The contact cleaner you mention is ok. But the DeoxIT 5 is a superior product. Available on Amazon.

I would hope the jack screw is greased at annual?? what access panel on a longbody gives access to the flap jackscrew?

 

The belly panel.   It's all one. Oh and lube trim U joints and such. 

It probably does not need to be greased that often but every other time turns into never. 

 

 

[Ragsf15e]

17 minutes ago, tls pilot said:

Agree. The contact cleaner you mention is ok. But the DeoxIT 5 is a superior product. Available on Amazon.

I would hope the jack screw is greased at annual?? what access panel on a longbody gives access to the flap jackscrew?

 

You have to take the one piece belly off.

Normally im a fan of contact cleaner spray and deoxit, however, these switches are available and relatively cheap at the electrical supply places online.  Mine had a dead spot and initially the contact cleaner worked, but only for a week and a couple flights.  I had to take the belly off twice to eventually go back a replace the switch which I probably should’ve done the first time.

[Yetti]

I had to do the contact cleaner twice on the 50 year old F model.    Then it was the relay.   The cool thing about the relay was there were two sides to it.   So I just switched wires to the other side.