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Mooneys are water resistant not water proof...


Trenta

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I found out the hard way that the avionics access panels are less than good as keeping rain out let alone a hurricane.

I completed my cross country trip today with my return back to John Wayne however 3 days ago I cringed when I returned to the condition my plane was in after being stranded on the ramp during Eta this last week. I was at St. Pete Fl (KSPG) and they were fresh out of any hangar or covered space. I also foolishly left my Bruce’s cover at home because I was concerned about W&B. Suffice it to say I will NEVER leave it at home again. I will leave a couple pair of jeans home next time instead. 
 

Long story short, my carpet was soaked through. My entire panel had a bath and I was rather startled by the amount of water that shot out of the nose cone on start up. It was very soon clear that my radios were totally InOp. Good news is wasn’t any new dings, dents, or control surfaces damage. Also luckily I met a really nice Aussie named Hayden at the avionics shop on base after an hour of labor, compressed air, and some preventative corrosion countermeasures everything was back in working order. 
 

That night I started my journey back west and found hangar space at Austin Executive where I pulled the carpets, did a little rinse with distilled water, and set up a fan to blow the interior dry for 48 hours. Upon my return I found that there was some lubricating to be done mostly on the step wheel, fuel selector, and trim wheel.

This week I am going to do an oil change and will be pulling the cowl. I will be inspecting for the signs of salt water in there and will be doing some rinsing and lubricating there. I also saw that we have a distilled water hose at John Wayne. Outside of a good rinse with that what else can I do?

Also my CHT gauge is getting stuck and needs some tapping to catch up and my EGT gauge is intermittent. Any thoughts here? 
 

What other precautions should I take to ensure that I don’t have really big knock-on consequences down the road from having my plane covered in hurricane salt water? 

-Trent

 
 

 

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Just now, carusoam said:

Looks like the strong winds may have tipped you sideways....

:)

Glad you are getting everything dried out...

Did you see any water in the static system too?

Best regards,

-a-

 

5201873A-0BED-4DCC-943A-361F4E80426F.jpeg

Thanks for the rotation! I didn’t notice any issues with the pitot static system however the previous owner rewired the static system tubing in the back to go along the top of the fuselage instead of the bottom to prevent clogging and allow better drain.  

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Ouch.

I think I’d take the 1000 screws out of the bottom panels and make sure all the gear and control rods dry out completely.  I’d have to assume water got down there if your interior was wet.  With it open, you can properly grease your trim too. Man that stinks.  Sorry to hear it.

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The avionics cover cowling piece in the early Mooneys (mine is a '65 C) is notorious for leaking water if it isn't really well sealed.  I had an experience similar to yours a few years ago, and didn't identify the problem at first. The carpet was wet at the very back -- where it meets the rear passenger seats -- so I thought it had something to do with water coming in the overhead air vent. Then my top radio in the stack started acting erratically and powered off sometimes.  I didn't connect the two issues, but then I noticed that the carpet over the nose gear hump directly beneath the avionics panel was also wet.  The water was leaking through the cowling, making its way through my avionics, dripping onto the carpet below, and then finding the lowest spot in the passenger compartment.

The solution is to seal up every millimeter of the cowling, with silicone sealant if necessary.  Just seal it every time you remove & replace.

My C has been a ramp aircraft all its life, and other than the avionics cowling, the only leak problem was years ago when water started getting through the little pilot window opening.  A new trim seal fixed that.

 

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My M20C had a couple of water leaks...

The ceiling air vent drain tube failed....

Having a cover took care of these issues...

When getting a new cover... make sure it extends over the radio access panels as well...

Each year these get opened at annual... and I would wonder how well they got sealed each time...

3M makes a great temporary sealing putty for this...

PP thoughts only, not a mechanic...

Best regards,

-a-

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https://www.aircraftspruce.com/catalog/appages/windowsealant.php

This stuff is nasty, gets stuck to your hands, clothes, etc. But a thin bead, applied to the airplane, and then squashed down with the avionics panel screws, will seal your panels and it is pliable enough to open them back up easily for service. Every so many openings, the dirty job of pushing the caulk around is done, adding a dab here or there as necessary to keep the seal continuous.

Maybe others use a different tactic but my IA suggested this and it works.

Edited by Immelman
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5 hours ago, Immelman said:

https://www.aircraftspruce.com/catalog/appages/windowsealant.php

This stuff is nasty, gets stuck to your hands, clothes, etc. But a thin bead, applied to the airplane, and then squashed down with the avionics panel screws, will seal your panels and it is pliable enough to open them back up easily for service. Every so many openings, the dirty job of pushing the caulk around is done, adding a dab here or there as necessary to keep the seal continuous.

Maybe others use a different tactic but my IA suggested this and it works.

That’s the stuff I use, on the air frame skin there is a bead roll for water drainage with weep holes on panels, do not block that groove 

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Contrary to popular beliefs around here it doesn’t rain salt water here in Florida. Don’t worry about that. 
 

the odds of that cover making it through the winds in 1 piece isn’t great, and if it didn’t you likely would have had the same issue and lost your cover. Where I’m at we remove the covers for major wind and rain events. 
 

poor waterproofing is your problem. You need to seal your panel with silicone. 

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12 hours ago, Bob E said:

The avionics cover cowling piece in the early Mooneys (mine is a '65 C) is notorious for leaking water if it isn't really well sealed.  I had an experience similar to yours a few years ago, and didn't identify the problem at first. The carpet was wet at the very back -- where it meets the rear passenger seats -- so I thought it had something to do with water coming in the overhead air vent. Then my top radio in the stack started acting erratically and powered off sometimes.  I didn't connect the two issues, but then I noticed that the carpet over the nose gear hump directly beneath the avionics panel was also wet.  The water was leaking through the cowling, making its way through my avionics, dripping onto the carpet below, and then finding the lowest spot in the passenger compartment.

The solution is to seal up every millimeter of the cowling, with silicone sealant if necessary.  Just seal it every time you remove & replace.

My C has been a ramp aircraft all its life, and other than the avionics cowling, the only leak problem was years ago when water started getting through the little pilot window opening.  A new trim seal fixed that.

 

Bob Where did you get the new seal?

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1 hour ago, rbridges said:

I know this is small consolation, but it may not have been salt water.  Unless it was spray from the ocean itself, the rain from the hurricane is prob fresh water.  Still cringy though.  Did all that come through the avionics panels?

So my knee jerk wasn't that it was salt water until I looked at my trim wheel and saw salt crystals forming. I was at albert whitted KSPG. They are right on the bay, the storm surge splashed enough salt water on to the runway and ramp for there to be some standing water and I think the wind blew it around everywhere.

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2 minutes ago, Trenta said:

So my knee jerk wasn't that it was salt water until I looked at my trim wheel and saw salt crystals forming. I was at albert whitted KSPG. They are right on the bay, the storm surge splashed enough salt water on to the runway and ramp for there to be some standing water and I think the wind blew it around everywhere.

That's lovely.  Hopefully your anticorrosion measures will keep the salt water from causing too much issue inside your plane.  

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Bob Where did you get the new seal?

It's just clear silicone sealant applied sparingly with a caulking gun and then pushed into the gaps with one's fingers.  When you have to open it up, the sealant can be removed pretty easily and when the cover is reinstalled new sealant applied.

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I like this thread .. especially as a wood wing owner.  I tell people to buy a wood wing mooney  - back in the day - and leave it out on the ramp day in/day out - would be like buying a Steinway grand piano and leaving it out on the driveway and then bitching cause it won't stay in tune.

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On 11/15/2020 at 9:35 PM, Immelman said:

https://www.aircraftspruce.com/catalog/appages/windowsealant.php

This stuff is nasty, gets stuck to your hands, clothes, etc. But a thin bead, applied to the airplane, and then squashed down with the avionics panel screws, will seal your panels and it is pliable enough to open them back up easily for service. Every so many openings, the dirty job of pushing the caulk around is done, adding a dab here or there as necessary to keep the seal continuous.

Maybe others use a different tactic but my IA suggested this and it works.

You got to remove it every year though at annual. I’ve been outside 20 years now and never had an issue with the rubber seals. Just inspect them at annual.  
 

-Robert 

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 search google "avionics bay weatherstripping site:mooneyspace.com" Turns up this thread:

This stuff WORKS.  No black goo. Also do fashion a roof for  your avionics stack as @Jerry 5TJ suggests.  That is covered in the above thread too.

Proof:

Earlier this year I penetrated the outskirts of decaying tropical storm Beta over Arkansas.  According to the radar, it wasn't convective, but it was raining from the aft overhead vents, and the air scoop was down. The drain tube on my aircraft is open, so I assume was overloaded.  I experienced no issues with any other leaks.    @Hector recommended this stuff, he flies a lot in rainy Florida.

My first experience with poorly sealed avionics panels cost me an approx 2AMU service bill from Garmin for my 430W a couple of years ago.  Since installing this stuff backed up by a little silicone in the central gap region, no problemo.

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On 11/16/2020 at 5:13 AM, Pete M said:

I had the same problem. A sheet metal guy made a one piece panel for my e. Tight as a drum after that. Oh, i also put some construction grade plastic from hd over the radio stack. 

Anyone have photos of their water deflectors/ "tents" inside the avionics bay that they can share?  I'd like to do this, but am thinking they should be easy to remove for avionics work; maybe Velcro?

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On 11/23/2020 at 10:37 PM, SLOWR426 said:

Anyone have photos of their water deflectors/ "tents" inside the avionics bay that they can share?  I'd like to do this, but am thinking they should be easy to remove for avionics work; maybe Velcro?

See the thread I linked above.  Photos there.

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