Flap Problems - Intermittent On Auto Select

[Isham]

I almost hate to post this topic because there are so many on flaps already.  I have studied all of the other posts and have not found this same problem.  As background I did have a cracked solder joint in the board and soldered it as I found on this site.  This made the flap work, but with the issue I describe below.  I just replaced the flap relay board on the firewall with a new one, based on discussion with Arian at Flight Design.  Took 2-months to get the new board.  No change. 

Here is the issue:

1.  Occasionally the flaps work perfect.  Maybe one out of ten times.

2.  If I set any flap position with the Master Switch OFF, when I turn on the Master the flaps go to the correct position.  After that, when I turn the switch to any other auto position the indicator changes but the flaps do not move.  If I go to manual I can move the flaps up and down okay.

3.  When I turn the Master OFF then back ON the flaps go right to the correct position and the same process as (2) above starts over.

I'm really pulling out my hair on this one.  Any ideas for how to troubleshoot this to narrow down the issue will be greatly appreciated.  I am hoping someone has had this same problem (not wishing it on anyone) and knows the fix.

[Isham]

One other thing I just thought of.  When I purchased the airplane the previous owner had just had the annual condition inspection done.  They did the 2-year wing structure inspection as part of that.  When I picked up the airplane he was baffled that the flaps only worked in manual mode.  Is it possible there could be a loose connection that causes the intermittent operation as a result of the wing inspection?

[Tom Baker]

1 hour ago, Isham said:

One other thing I just thought of.  When I purchased the airplane the previous owner had just had the annual condition inspection done.  They did the 2-year wing structure inspection as part of that.  When I picked up the airplane he was baffled that the flaps only worked in manual mode.  Is it possible there could be a loose connection that causes the intermittent operation as a result of the wing inspection?

The wing inspection would have no effect on the flap operation.

[GrassStripFlyBoy]

Here's a tale and a question around flaps / manual operation.  First - I've been searching past posts on this topic, and see my SW should be in the window of time with "180 from 15 degrees" manual feature as July 14, 2006 build date.  The factory manual with my serial # on it includes reference to this feature, I reviewed to see if I was missing something, and what I gather is it simple rotates around continuing beyond the -40 detent, correct?  I ask this because as other threads indicate, there is a stop for switch at +6 & -40, and I pushed pretty hard to confirm both ways.

So, here's the strange thing - I swear when I had the switch removed from panel (entire unit detached, pot nut, lever, 2x screws above the LED, etc) for the new panel updates I've been sharing, I turned the pot and was surprised it went almost all the way around into that manual region 180 over from 15.  I distinctly recall thinking - I wonder why I never noticed that much travel before.  Now, maybe I was confused with the flap lever being off pot and apart, but I generally have a pretty good sense of expecting 5 notches and seemingly being a lot more, like double.  So, before I open all this back up - thought I'd ask the question.  Perhaps I influenced something with my new panel, unlikely, I examined closely the size of hole for pot as well as the tiny hole for keying post that engages backside panel for anti-rotation forces.  I also just went and pushed on that small keying post to confirm it is not a release or stop / catch, not that either.  I think this is a mystery worth opening back up, but also wanted to toss up here.

[GrassStripFlyBoy]

I'm on to something here - I just removed panel section, removed flap lever and pot nut, rotated around to detents and it remained to stop at -40.  I thought I must have been confused before, but I also then pushed the pot / board looser to panel and noticed a washer float up off top of pot - and then it rotates around into the manual mode region!  I'll grab phone and remove the rest of assembly off panel to determine the mechanics in this.  More to come.

[Isham]

I had a prior issue with my rotary switch.  Here is a post that shows the fix and how the rotating positions work:

https://planetools.com/ctsw-rotary-flap-switch

There is also discussion about the switch at this link:

 

 

[GrassStripFlyBoy]

And the rest of story, here is pic of when pot released off back of panel and washer lifted up:

And here is a view of washer (with stop tab / tang) and the face of pot with multiple locations to install that tab.  Have not proceeded into what tab slot combo is needed, likely each location is one more detent stop forward and this needs to be reinstalled to all the way over to "flap up / manual" final detent stop.  Unsure if someone changed this to limit -40 setting as max prior to my ownership, or if the factory build it as such - but nice to know I'm rocking the manual flaps!

[Isham]

Darrell, glad you figured it out.  Back to my original issue of intermittent auto flaps.

Tom, thanks for the input on the wings.  I didn't know if there were any connectors that could potentially cause this issue when they removed them for the inspection.  I'm just really baffled by the intermittent nature of this issue.  It would not be bad if it worked 9 out of 10 times, but failing to work 9 out of 10 times is really disturbing. 

Do you think the flap controller could cause this?

[Tom Baker]

Other than replacing a flap board I have not had to address any flap issues. 

[Anticept]

On 6/6/2020 at 2:56 PM, GrassStripFlyBoy said:

And the rest of story, here is pic of when pot released off back of panel and washer lifted up:

And here is a view of washer (with stop tab / tang) and the face of pot with multiple locations to install that tab.  Have not proceeded into what tab slot combo is needed, likely each location is one more detent stop forward and this needs to be reinstalled to all the way over to "flap up / manual" final detent stop.  Unsure if someone changed this to limit -40 setting as max prior to my ownership, or if the factory build it as such - but nice to know I'm rocking the manual flaps!

 

That washer is exactly for that purpose, it's the stop. Depending on the controller model, the additional steps won't even be wired anyways.

What likely has happened is the nut came loose, vibration loosened the ring, and then someone tightened that back up. Happens a lot.

[Isham]

Back to my very first post on this topic: The last two flights the flaps have worked flawless.  But, in the hangar (battery power only) I still have the issue originally described.  Any ideas?

[Roger Lee]

It may be just low voltage. This used to be able to be adjusted. Should be a plastic screw on the circuit board on the back of the firewall. If you push the plane out and try to run the flaps and they don't work and then start the plane and run it up around 3K rpm and they work ok then you have your answer. Low voltage to the flaps.

[Isham]

Thanks for the input Roger.  I will check that out.  If I remember right mine has a place for a small screwdriver to make an adjustment.  Any idea how much or which way to turn the adjuster?

[Roger Lee]

It's been so long I'm not 100%. Clockwise and try a 1/4 turn first.

[FlyingMonkey]

So I reported intermittent slow flap movement speeds in another thread.  I have greased the sliding arm and did another fix Roger suggested in a phone call.  No dice, it's still slow, but usually only on the first flap movement or two of the day, then it's fine, which to me points to inadequate lubrication *somewhere*...

Yesterday when doing a little troubleshooting I noticed on some flap movements, especially when the flaps are going down from -6° or 0°, there is a momentary "bang" noise from the right side wing as the flaps fist start their travel.  To me that sounds again like lack of lube, like something is binding up and breaking free.

My next step is to get out the INOX and hose down all the pivot points and rod ends in every flap position, to see if I can eliminate any issues with lack of free play.  I'm open to any other suggestions if anybody has them.  Maybe turn up the flap voltage as Roger mentioned above?  I could also take apart the pivots and grease the hell out of them.  I am trying really hard to avoid disassembly of the flap jack screw and motor assemblies, but that's in the mix too if I have to.

[Isham]

My flaps have never seemed too slow.  When they work they move relatively fast. 

I flew yesterday.  Flaps worked perfect in the air, then in the hangar after the flight.  I have not tried to adjust the voltage yet but if I have any more issues I will try that.  For now I am going to just continue to fly and monitor. 

I didn't realize the CTsw had a self repair feature on the flaps!

[Roger Lee]

You should always test the flaps under at least 3K) rpm to make sure the voltage output to the aircraft is up. Running at idle with all lights, instruments and any other voltage draw brings the entire voltage to the system down. This is why usually people report slow flaps on the ground, but are okay at cruise rpms.

[FlyingMonkey]

37 minutes ago, Roger Lee said:

You should always test the flaps under at least 3K) rpm to make sure the voltage output to the aircraft is up. Running at idle with all lights, instruments and any other voltage draw brings the entire voltage to the system down. This is why usually people report slow flaps on the ground, but are okay at cruise rpms.

My flaps are slow even at 3000+ rpm on the first cycle or two of the day, then they are fine.  It's really seeming like a lubrication issue somewhere.

I did drill a hole into the motor case as we discussed, and shot INOX over the little gearset in there.  Minimal difference, so I think the issue might be the pivots on the wing end.  I'll report after lubing all that stuff.