KFC auto pilot buttons sticking

[DaveMC]

So I go out to my hanger which is in mid Missouri and it’s an insulated hanger but it does not have AC in it or any other air-conditioning type of unit. I open the hanger door and I walk out onto the hanger floor and nearly slip and fall  because there’s so much condensation inside the hanger. I pull my aircraft out line it up get inside do a start get the engine up and push the KFC 150 test button in and it stays in and of course it’s staying in a stat test condition and will not come out of it. I take a small pair of pliers pull it out and go through it again and it works fine. Anybody ever experienced this or know what the heck is going on

[moxfox]

Not good I would say ? I would put a dehumidifier inside of that airplane.  That much moisture cannot be good for the radios or any other electrical connections I would think. 

[PeteMc]

Dehumidifier is one option.  But if there is that much humidity, I'd look into putting a couple of little hatches in the walls on either side of the hangar.  On one of them I'd put a little fan to make sure there is air movement.  If no power, make it a solar fan and put it on the sunnier side of the hangar.  (And screening to keep out the bugs and birds.)

[spistora]

I was surprised at how well a dehumidifier works in a t-hangar.  I picked one up for under $200 on amazon and it has worked great.

[DaveMC]

Yeah  That's my plan.  Still wondering about the test button though  maybe i just broke a spring

[jaylw314]

If you don't have power (or have to park outside for an extended time), you can get cans of silica gel drying agent.  Stick them in an electric convection oven for a couple hours, then seal them in zip loc bags when they're dry.  If you have a few, you can bring them with you on trips and leave them in the plane to keep things reasonably dry.  Also reduces windshield fogging up on cold days

I haven't tried this one, but I can't find the ones I bought a few years ago.

Be careful with calcium mineral dessicant, some of them simply dissolve in moisture into brine, which you don't want to spill in the plane.

[LANCECASPER]

16 hours ago, DaveMC said:

Yeah  That's my plan.  Still wondering about the test button though  maybe i just broke a spring

I would call Jake at Bevan Rabell in Wichita KS. They special in these autopilots. https://bevanaviation.com/

[PeteMc]

On 7/1/2021 at 7:17 PM, DaveMC said:

I take a small pair of pliers pull it out and go through it again and it works fine.

So the Text Button works (comes out on its own) after you've pulled it out after the first time?

Some contact cleaner may do the trick to clean up whatever is gumming up the button.  If you don't have any electronic stores around, WD-40 actually makes a contact cleaner and is usually available at Home Depot.  (Regular WD-40 would actually work too, but much thicker and then there's the smell on your fingers.)

[Jake@BevanAviation]

I would advise to not use regular WD-40 on any electrical connection.   If you are looking for something to clean a switch or connector find a specific cleaner that dries fast and leaves no residue like Hi-Line.  HI-Line is what I use on a daily basis to clean contacts and connectors on the vast majority of systems I work on.  I have seen first hand what regular WD-40 can do to a unit if the residue is not properly cleaned off.

 

[PeteMc]

Yea, good catch.  I should have clarified if you had to, a tiny bit of regular WD-40 on a Q-Tip or something.  Was thinking more the Contact Cleaner as stated. 

 

[tls pilot]

Agree that you should not use WD40

We have had great success with Caig DeOxIT5 and if additional lube needed use DeOxIT Fader

both safe on plastics

 

[DaveMC]

OK so here’s an update

 

First thank you all for your input and I may end up needing to put some contact cleaner on a few things so those resources were amazing

 

So it sat inside a climate controlled hanger at the FPO where I was launching from then it was moved outside where it could get some ventilation.

 

so it sat inside a climate controlled hanger at the FPO where I was launching from then it was moved outside where it could get some ventilation.

 

When I climbed into it to take my flight from Columbia Missouri to Denver Colorado all buttons were working normally and it is as if nothing had happened

 

with that I am absolutely convinced that it was the excessive humidity for an extended period of time that caused the buttons to do that. When I push the test button in and pulled it out with a pair of pliers it was as if the spring did not exist. Yesterday and today everything is functioning normally but I am in a dry environment. 

[thinwing]

with that kind of humidity...i would worry about corrosion inside the engine,especially cam lobes and tappets,cylinder walls...

[tmo]

I put kitty litter in an open plastic box in the cockpit; after a few weeks, I replace it with another batch, which I have previously baked in an oven at 125C / 260F for 2h.

[LANCECASPER]

2 hours ago, tmo said:

I put kitty litter in an open plastic box in the cockpit; after a few weeks, I replace it with another batch, which I have previously baked in an oven at 125C / 260F for 2h.

And if any polite vermin wander into your airplane maybe they would use it.