My Acclaim's right fuel tank is leaking. Sigh.

[Joe Zuffoletto]

In the past month or so I've developed a fuel stain on my wing walk. Darn. Guess I'll be resealing at my next annual in a few months.

Any danger in operating the plane in this condition?

[N6758N]

7 minutes ago, Joe Zuffoletto said:

In the past month or so I've developed a fuel stain on my wing walk. Darn. Guess I'll be resealing at my next annual in a few months.

Any danger in operating the plane in this condition?

I can't speak for an Acclaim specifically, but on most other M20s the tanks don't go back that far. Could be something else going on.

[jaylw314]

Dumb question, maybe, but is it actually fuel?  Are you parked under a dripping hangar roof?

[Joe Zuffoletto]

The maintenance facility at my airport thinks it's fuel. It's definitely not a leaky hangar roof. It's dry season out here. Also, I tried to scrub it off but then it came back.

I'll shoot the photo to Mooney and see what they think.

[Marcopolo]

I agree with Terry,

  That looks  to be behind the rear fuel tank bulkhead (the spar), and I would expect the blue dye which doesn't evaporate to make a much darker stain.  

[rbridges]

could you put a white paper towel on it with pressure and see if it wicks up blue?  my tanks leaked through the wingwalk, but the stain wasn't that big and was located a little more forward.

[Joe Zuffoletto]

Keep the good ideas coming! I'm heading to the airport this afternoon to investigate further.

[N6758N]

Joe, 

The mooney tanks are located forward of the spar, see if these pictures of my recent entry into my fuel bay helps at all. The spar is only a few inches aft of the access plate in the middle of my pic. 

[mike_elliott]

Joe, I just sent your pic off to Paul Beck to get his expert opinion.

 

and here it is....

 

Hi Mike, it should be too far back, and nothing leading to it either. Look up at the wing walk underside,  see if you can see anything. 

 

Paul

 

 

 

Paul Beck

Weep No More/Oasis Aero 

320-295-1671

weepnomorellc.com

Oasisaero.com

[Jeff_S]

If it's fuel you can definitely smell it. I have a small leak under the wing walk in the usual place, and it's bigger when the tanks are full. But in my case you just rub your finger on it and you can smell the avgas.  Where yours is located, it's hard to imagine what else it could be besides fuel to produce that big a stain.  Have you noticed a difference depending on the level of fuel you keep in the tank?

[LANCECASPER]

If you use a heat gun you can peel back the wingwalk and see underneath.

It could be one of the screws under the wingwalk that's leaking and then maybe the fuel is running down to where you see it? If it is, those are easy to fix.

Go to this link and read the paragraph "Panel Screws" :     http://donmaxwell.com/publications/MAPA_TEXT/_overlay/Fuel Tank Repair_How We Fix Them 2-05.htm

 

[RobertGary1]

Even if that were fuel is an almost comically small leak. The manual doesn't require action taken for that small of a seep. They come from the factory losing more fuel than that. These are wet wings.

 

-Robert

[N6758N]

2 minutes ago, RobertGary1 said:

Even if that were fuel is an almost comically small leak. The manual doesn't require action taken for that small of a seep. They come from the factory losing more fuel than that. These are wet wings.

 

-Robert

Wet wings aren't supposed to leak fuel...and they aren't meant to be patched once a week either. I would hope a 10 year old Mooney wouldn't need fuel tank work done yet...

[Bob_Belville]

Just now, RobertGary1 said:

Even if that were fuel is an almost comically small leak. The manual doesn't require action taken for that small of a seep. They come from the factory losing more fuel than that. These are wet wings.

 

-Robert

Now, excuse me but that statement, not the leak, seems silly to me. 

Of course my old E model has 20 year old bladders, something an Acclaim should never need since it was built after wet wing technology was absolutely perfected and owners would never have to deal with tank leaks again.

[peevee]

Sorry Joe.

 

If there are indeed screws under there the Maxwell procedure will work, I have used it myself. I'm not familiar with what's under that compound.

[Oldguy]

12 minutes ago, Hyett6420 said:

If the wing is the same (ish) to a J then that line of rivets coming out of the bottom left of the pic is roughly where your spar is and that is the rear of your tank.  

If this is fuel, then

1. it will dry out if the tanks are not full so will leave a blue patch, not what looks like an oil stain
2. it would unlikely leak at that spot.
3. having said 2, it could be a leak in front of the spar and is showing itself at that pint, a bit like a water leak in a house roof.

so what else runs out there?

1. do you have deice?  If so is the deice leaking out at this point? 
2. Has someone dripped some oil and not owned up?

suggest you empty the tanks, look with a boroscope in the far right side for bubbling etc that indicates weak sealant.  Im pretty sure its not a leaking tank though.

if FIKI follow the piping to see if it goes anywhere near there.

Just a Brits ideas, and what the heck do we know.  

Andrew

Good thought. Unless he has some custom leading edges on the rear of the plane, it looks to have a deice system.

[thinwing]

14 minutes ago, Hyett6420 said:

If the wing ismthe same (ish) to a J then that line of rivets coming out of the bottom left of the pic is roughly where your spar is and that is the rear of your tank.  

If this is fuel, then

1. it will dry out if the tanks are not full so will leave a blue patch, not what looks like an oil stain
2. it would unlikely leak at that spot.
3. having said 2, it could be a leak in front of the spar and is showing itself at that pint, a bit like a water leak in a house roof.

so what else runs out there?

1. do you have deice?  If so is the deice leaking out at this point? 
2. Has someone dripped some oil and not owned up?

suggest you empty the tanks, look with a boroscope in the far right side for bubbling etc that indicates weak sealant.  Im pretty sure its not a leaking tank though.

if FIKI follow the piping to see if it goes anywhere near there.

Just a Brits ideas, and what the heck do we know.  

Andrew

That's a good suggestion about the antiice...because it is so far aft and he hasn't reported and blue stains under wings..I thought tks fluid also

[RobertGary1]

If this was a "leak" it would be evaluated per the Manual. Just because fuel comes out of the tank does not make an airworthiness item.

-Robert

[thinwing]

Of course. His plane is blue..so early staining might not show

[RobertGary1]

22 minutes ago, thinwing said:

Of course. His plane is blue..so early staining might not show

When in doubt just taste it. You'll know if its fuel if you rub your finger on it and stick it in your mouth.

-Robert

[thinwing]

No thanks to taste test

[steingar]

Never saw anything leak up before, but perhaps I'm only inexperienced.

[LANCECASPER]

52 minutes ago, Hyett6420 said:

If the wing ismthe same (ish) to a J then that line of rivets coming out of the bottom left of the pic is roughly where your spar is and that is the rear of your tank.  

If this is fuel, then

1. it will dry out if the tanks are not full so will leave a blue patch, not what looks like an oil stain
2. it would unlikely leak at that spot.
3. having said 2, it could be a leak in front of the spar and is showing itself at that pint, a bit like a water leak in a house roof.

so what else runs out there?

1. do you have deice?  If so is the deice leaking out at this point? 
2. Has someone dripped some oil and not owned up?

suggest you empty the tanks, look with a boroscope in the far right side for bubbling etc that indicates weak sealant.  Im pretty sure its not a leaking tank though.

if FIKI follow the piping to see if it goes anywhere near there.

Just a Brits ideas, and what the heck do we know.  

Andrew

I think we have a winner - a TKS leak makes the most sense especially since he doesn't notice a fuel smell.

I bet the fitting where the arrow is pointed is the culprit. When was the last time you ran the TKS pump Joe?

 

 

[Guest]

2 hours ago, RobertGary1 said:

If this was a "leak" it would be evaluated per the Manual. Just because fuel comes out of the tank does not make an airworthiness item.

-Robert

Can't really use a 1980 Maintenance manual on a mid 2000's TN.  And I can't see fuel leaking from the panel under the wing walk running back that far.

Clarence

[smccray]

20 minutes ago, M20Doc said:

Can't really use a 1980 Maintenance manual on a mid 2000's TN.  And I can't see fuel leaking from the panel under the wing walk running back that far.

Clarence

Same type certificate though.  Caution is certainly recommended using old documentation for anyone signing off on airworthiness, but somehow I doubt the documentation has changed. I'd give the proverbial 2 points to Robert unless someone finds more recent documentation.