Anyone seen this odd tank in the wing?

[khedrei]

Long story short. Plane is in for auto pilot and panel redo and while working on the roll servo install this was found. He has no idea what it is and neither does a mooney mechanic in the area. 

Called mooney and they also have no idea. It's not in my canadian logs and I dont have all the american logs. 

He says it appears to be some sort of surge tank which is hooked in line with the fuel vent line. It hooks right into the fuel tank. 

We are at a loss and aparently it cant be relocated and will interfere with the bolts that mount the roll servo.

Thoughts? Anyone know what it is?

[N201MKTurbo]

Redneck field modification.

Is it on both sides?

[ArtVandelay]

On boats we have air/fuel separator, prevents fuel from coming out of the vents:

 

https://www.westmarine.com/buy/racor--lifeguard-fuel-air-separator-vent-protector--437301

 

This could be a homemade version of above. Get a borescope, put it through closest screw in inspection plate to see if you have it on other side.

 

Tom

 

 

[khedrei]

Dont know. It was under a riveted panel. They only needed to remove one side for the roll servo so they didnt drill out the same panel on the opposite side. I just dont get what the mod is for. Too small to be any kind of range extender. Aparently it has a vent line connected and then it connects to the fuel tank.

It looks to have been customized to fit around the stiffeners. 

[anthonydesmet]

Hmmmm, only because I’ve been on the limited DOD enforcement side of things and have observed “weird” encounters I will ask this question .....uhh history of plane? Southwest plane, Florida?.....it does look like a hanger elf fuel mod though....and you may have the makings of your own patent.....

[khedrei]

Thanks. I'll suggest he check that. Its killing my auto pilot install. Hes not sure what it is so he cant just remove it. 

[khedrei]

It was owned by the Illinois state police in the 90s. I dont have the whole history but I think its spent most of its life in the North. Imported to Canada in 2013 I think. 

[anthonydesmet]

Hmm, I’m guessing state police mod for extra loiter time.......anybody else?  No logbook entry in the 90’s? I  may have missed it but did you look under other wing? I bet there is another.  I’m guessing they are two to three gallons each....total approx time 20-30 minutes extra flight gravity fed with external pressure......pretty slick though......and before Jose’s fuel tank mod if it was in the 90’

[INA201]

1 hour ago, khedrei said:

Long story short. Plane is in for auto pilot and panel redo and while working on the roll servo install this was found. He has no idea what it is and neither does a mooney mechanic in the area. 

Called mooney and they also have no idea. It's not in my canadian logs and I dont have all the american logs. 

He says it appears to be some sort of surge tank which is hooked in line with the fuel vent line. It hooks right into the fuel tank. 

We are at a loss and aparently it cant be relocated and will interfere with the bolts that mount the roll servo.

Thoughts? Anyone know what it is?

I’d ask a couple of MSCs on this one. Looks fairly well constructed.  I’d get some input on removal regardless of what it is. However, we all wanna know this one.

[ohdub]

Maybe it's the chemtrail tank? 

[khedrei]

Haha. Or it's full of crystal meth...

[anthonydesmet]

4 minutes ago, khedrei said:

Haha. Or it's full of crystal meth...

Hah!  That was my initial thought or something like it.....but I’m thinking the state police needed more flight time in the 90’s and @jose hadn’t come out with his STC yet.

[takair]

I was going to guess smoke tank, except it wouldn’t be tied to the main tank.  There were a couple of air show Moonies in the 80s, one was a K, I believe.  

[khedrei]

Hes telling me it's only about a half gallon. Even if hes wrong it's probably no more than 1 or 1.5... seems odd as an extender. 

Edited December 20, 2019 by khedrei

[kortopates]

Thanks. I'll suggest he check that. Its killing my auto pilot install. Hes not sure what it is so he cant just remove it. 

I would think as soon as you can determine it's not an approved mod, through a combination of factory input and review of logs, 337's and Wt&Bal updates you should have no problem pulling it and returning the planes tank vent to factory specs.

 

 

Sent from my iPhone using Tapatalk

[anthonydesmet]

1 minute ago, kortopates said:

I would think as soon as you can determine it's not an approved mod, through a combination of factory input and review of logs, 337's and Wt&Bal updstes you should have no problem pulling it and returning the planes tank vent to factory specs.


Sent from my iPhone using Tapatalk

Im with @kortopates ......but it sure is fun to hypothesize.......

[khedrei]

5 minutes ago, kortopates said:

I would think as soon as you can determine it's not an approved mod, through a combination of factory input and review of logs, 337's and Wt&Bal updates you should have no problem pulling it and returning the planes tank vent to factory specs.

 

 

Sent from my iPhone using Tapatalk

Thanks. I'll look for a mobile mechanic willing to head there, implement and sign off on the removal/ fix.

Edited December 20, 2019 by khedrei

[tmo]

@khedrei - can you get the FAA history from when the plane was under FAA?  The stuff you order online through here.

[takair]

1 minute ago, khedrei said:

Hes telling me it's only about a half gallon. Even if hes wrong it's probably no more than 1 or 1.5... seems odd as an extender. 

I suspect Tom had it right.  Police can operate under public use rules, so paperwork may be lacking.  Perhaps they had a policy to top the planes off prior to hangar in.  Then, when fuel would come out of the vents, perhaps they had no tolerance for fuel on the hangar floor, so someone came up with this solution?  Might be a cool solution for that scenario.  If done right, the fuel would always be topped off, even after moving it cold to warm.

[khedrei]

1 minute ago, takair said:

I suspect Tom had it right.  Police can operate under public use rules, so paperwork may be lacking.  Perhaps they had a policy to top the planes off prior to hangar in.  Then, when fuel would come out of the vents, perhaps they had no tolerance for fuel on the hangar floor, so someone came up with this solution?  Might be a cool solution for that scenario.  If done right, the fuel would always be topped off, even after moving it cold to warm.

That does make a bit of sense.

 

Thanks tmo. I looked at that. I will order mine and see what comes out of it. I'm not in a rush to get the plane back but he may want it out of his shop if I cant sort this out in a reasonable time. 

[EricJ]

Smuggle tank or nitrous.   

Maybe there is cash inside.   Or equivalents.

[chrisk]

Header tank for inverted flight?

[Shadrach]

5 hours ago, khedrei said:

It was owned by the Illinois state police in the 90s. I dont have the whole history but I think its spent most of its life in the North. Imported to Canada in 2013 I think. 

Why not reach out to the Trooper's Aviation dept.  25 years isn't that long ago. Doubtful any of the current staff are familiar with the plane but maybe they can point you to someone who might be.  I think Takair's theory is most plausible but it seems like a lot of work compared to just wiping up a small blue stain ever now and then. 

Edited December 21, 2019 by Shadrach

[carusoam]

Check for the pair...

The only explanation for a tank on the vent tube is to handle the over-flow...

I have yet to see a Mooney tank overflow out the vent... the vents are often, way up hill... Most often, I can’t afford to fill them all the way up...  

It takes studying the height of the fill hole vs. the Location of the vent... 26gallon tanks may be able to overflow the vent...?

There are two types of Mooney tank vents... tube in a tube... or a high corner of the tank vented to a reverse NACA duct on the bottom of the wing...

Only one problem with this explanation... if fuel overflows and fills this tank.... where does it go after that?  How does it get emptied...?

What type of tank vent does the plane have...?  Tube in a tube, doesn’t have a way to connect an aux tank in the wing...

+1 on returning the fuel tanks to the original design...

PP thoughts only, not a mechanic...

Best regards,

-a-

[xcrmckenna]

Haha. Or it's full of crystal meth...

In that case you’ll have a new Acclaim...


Sent from my iPhone using Tapatalk