DC PA-22 fuel tanks in PA-12

[MT54]

HI. We are restoring a customer's 1946 PA-12 and he wants the Aerospace Logic fuel gauge with the CiES digital senders. Looks like this can only be done using Dakota Cub's tanks that are STC'd for PA-20/22 only. Anyone out there have experience in getting field approval for these tanks in a PA-12? Thank you.

[wireweinie]

What's the limiting factor on the gauges/senders? Fit or paperwork?

Web

[MT54]

Paperwork. The gauge is STC'd for the airplane when using these senders. Unfortunately the tanks are not. They seem to be identical to the 23 gal tanks that are STC'd for the PA-12 but have the cutout to accept the senders. The PA-12 tanks are made to accept the sight gauge, which the owner would rather not use.

[stewartb]

Your owner is nuts. Properly oriented sight gauges are far better than digital. That from a guy with AL fuel gauges, who had to add an FS-450 to know what the fuel level really was.

[wireweinie]

I just did a quick check of the AML on Aerospace Logic's website and I can't find a PA12 listed. Are you using the single gauge/dual sender setup?

Web

[MT54]

Yes. It's on line 70 of the AML

[wireweinie]

I see it now.

If the senders are the sticking point, contact CIES. Some companies will help since it means expanding their AML. Might be an easy add on if you have tanks that are physically identical to another already on the AML.

An aside here. I've installed these gauges and senders in a couple of Cessnas. I'm NOT a fan. Especially when you already have sight gauges that operate with no moving parts or power.

Web

[Gordon Misch]

Personal opinion - I like the wing root sight gages on the Atlee Dodge tanks. No metal housing and no corks or floating balls to malfunction. Very simple to install and maintain. A downside could be that they're sized for the deep 30.5 gal Atlee tanks.

For the metal housing style, Dakota Cub makes nice ones.

[Marty57]

Personal opinion - I like the wing root sight gages on the Atlee Dodge tanks. No metal housing and no corks or floating balls to malfunction. Very simple to install and maintain. A downside could be that they're sized for the deep 30.5 gal Atlee tanks.

For the metal housing style, Dakota Cub makes nice ones.

If not using the deep 30.5 gal tanks; any reason to not just use a piece of tygon tubing from the upper to the lower ports used for the site gauge? Seems simple enough.

Marty57

[Gordon Misch]

I wouldn't use plain ol' Tygon. Atlee uses Versilon in their pre-formed part. It's available bulk, as little as 5 ft lengths, from McMaster Carr for custom sizing. I'm sure it would need to be heated for forming to shape because it's quite stiff. 1/4" I.D., 1/2" O.D. Rugged stuff.

[Marty57]

I wouldn't use plain ol' Tygon. Atlee uses Versilon in their pre-formed part. It's available bulk, as little as 5 ft lengths, from McMaster Carr for custom sizing. I'm sure it would need to be heated for forming to shape because it's quite stiff. 1/4" I.D., 1/2" O.D. Rugged stuff.

Thanks; just need to figure out how to heat bend it.

Marty57

[stewartb]

Do Atlee’s tubes not fit standard tanks? My kit came with glass tubes and aluminum housings. I pitched them and used Atlee’s. I assumed my original tubes were standard Cub size.

[Gordon Misch]

I think not, because the Atlee tanks are deeper. However, if the gage ports were at a greater angle from vertical they could fit shallower tanks.

That's getting into the custom / EXP zone though, I think.

[Gordon Misch]

Thanks; just need to figure out how to heat bend it.

Marty57

Yeah, me too. Maybe hot water, then to a jig? I have enough raw material to do at least one pair, but I haven't yet made an effort at forming to spec.

[skywagon8a]

If not using the deep 30.5 gal tanks; any reason to not just use a piece of tygon tubing from the upper to the lower ports used for the site gauge? Seems simple enough.

Marty57

Clear flexible tubing from ACE hardware. Cut it to length, plug it in ... done. Still as good as new after 10 years. Reads to the bottom of the tank in level flight. Don't use this color for the backing plate.

[MT54]

I see it now.

If the senders are the sticking point, contact CIES. Some companies will help since it means expanding their AML. Might be an easy add on if you have tanks that are physically identical to another already on the AML.

An aside here. I've installed these gauges and senders in a couple of Cessnas. I'm NOT a fan. Especially when you already have sight gauges that operate with no moving parts or power.

Web

The senders are STC'd for the airplane when using A.L.'s gauge via the STC from Aerospace Logic. It's the tanks that are the issue. The tanks from Dakota Cub that are built to accept the senders are STC'd for PA-20/22 only, even though they seem otherwise identical to the tanks that are stc'd for the 12. My attempts to speak with the engineer at Dakota Cub on this matter have so far been fruitless. I realize though that they are probably very busy and short staffed as many companies are right now. What I am trying to do here is a fishing trip to find out if anyone out has applied for a field approval for putting DC's pa-2022 tanks into a pa-12. If they had been granted approval then the 337 would go a long way as acceptable data in trying to get one for this project. BTW, what sort of trouble did you encounter with these senders and gauges in the Cessnas?
Thank you, and all of you, for your replies!

[wireweinie]

-Install instructions were poor
-overly complicated diagrams
-difficulty just figuring out what specific gauges/senders work together
-mediocre fit of senders to tank

Still not clear on the issue with the tanks. If the gauges and senders are STC'd for all PA12's regardless of tanks, there will be instructions for installing the senders. Is the owner simply looking for an excuse to put in new tanks?

Web

[Steve Pierce]

I would think you would have adequate data for a field approval given a reasonable PMI but we all know how that can be. I would get a letter from Dakota stating the tanks are identical besides the fuel gauge configuration and provide your PMI with the STCs for both tanks, the senders and the gauges. They won't want to read all that but if you present the information the way he/she can understand it and they are reasonable it should be a slam dunk. You could also do a CAR3 compliance checklist. I give them so much data they are overwhelmed. Good luck. Other option is to educate the owner on the site gauges and an Electronics International FP5L fuel flow/totalizer. Way better information in my opinion.