New fuel tank gas caps

[N2613V]

I have been fighting with water in the fuel tanks for years on my C-170. Replaced the o rings and split washers, used the over wing fabric covers. After having N2613V turn into a sail plane a couple of miles from the airport I decided that something had to be done. After a lot of thought and research I submitted and idea to the local FSDO and got a 337 approved for a modification with Cessna 206 fuel tank caps. since installing the modification I have not had a single drop of water in the fuel.

The modification was a pretty simple process, wish I'd done it years earlier.

Send me a note if you have any questions. N2613V@sbcglobal.net

Mike

[spduffee]

The 206 conversion sounds pretty interesting. Do you have any photos available? You have fabric wings - would there be much difference applying this to an aluminum wing? What do you think the mod cost at the end of the day?

Thank you,

Shawn

[Bruce Fenstermacher]

The 206 conversion sounds pretty interesting. Do you have any photos available? You have fabric wings - would there be much difference applying this to an aluminum wing? What do you think the mod cost at the end of the day?

Shawn

Here is the problem with the 206 caps on an A or B model. AD 79 10 14 R1 applicable to all A and B models specifies at least one vented fuel cap. The 206 caps are not vented.

[spduffee]

So we have the center top mounted aerator, is this AD to provide for a redundant vent, in case that gets clogged by a bee or other debris?

[Bruce Fenstermacher]

So we have the center top mounted aerator, is this AD to provide for a redundant vent, in case that gets clogged by a bee or other debris?

Yes, I believe that was the final story.

[C170U2]

Got mine from spruce. http://www.aircraftspruce.com/catalog/a ... key=551152

Put a plunger over them when it rains and it keeps the water out. If you forget them they will blow off before takeoff.

[N2255D]

Believe it not, I got mine from Cessna about two years ago for $32 from Cessna. Spruce wanted $50. Looks like right now Spruce wants 56.75, Premier wants 43.20 http://www.parts123.com/PartFrame.asp?Z ... r_Aviation and Cessnaparts.com wants 46.50 http://cessnaparts.com/search.cfm

[GAHorn]

The 206 conversion sounds pretty interesting. Do you have any photos available? You have fabric wings - would there be much difference applying this to an aluminum wing? What do you think the mod cost at the end of the day?

Shawn

Here is the problem with the 206 caps on an A or B model. AD 79 10 14 R1 applicable to all A and B models specifies at least one vented fuel cap. The 206 caps are not vented.

Bruce, wouldn't a field approval negate the AD since it comprises a change of design?

[Bruce Fenstermacher]

The 206 conversion sounds pretty interesting. Do you have any photos available? You have fabric wings - would there be much difference applying this to an aluminum wing? What do you think the mod cost at the end of the day?

Shawn

Here is the problem with the 206 caps on an A or B model. AD 79 10 14 R1 applicable to all A and B models specifies at least one vented fuel cap. The 206 caps are not vented.

Bruce, wouldn't a field approval negate the AD since it comprises a change of design?

George the field approval, the one that was done, was done on a '48. It does not have vented caps and is not covered under the AD. So this particular field approval did not address AD 79 10 14R. And the problem I see IS covering this AD on any approval for later years. Replacing fuel caps with 206 caps is not terminating action for the AD.

[GAHorn]

A field approval being a form of one time STC"....altering a later airplanes fuel caps......I believe would negate the AD requirement, unless the FAA signatory restated it. It might be an erroneous oversight....but I think it would. (Not arguing about the airplane needing a secondary vent....only discussing how oversights can occur when modifications are involved, exactly as you noticed reference the ragwing conversion.)

[Bruce Fenstermacher]

I agree, if one got a field approval for the 206 caps on a A or B model and the field approval specifically addressed the AD, it would be fine. The AD addresses what is a terminating action. It also spells out who to check with for other means of compliance. All A and B models are required to comply with the AD in some form as spelled out in the AD or by alternate means granted by the approving authority in the AD otherwise the aircraft would not be in compliance.

[n2582d]

The the Aircraft Spruce link you provided made reference to "300 series caps and necks". On another post Richard provided a link to F.A. Dodge's fuel cap adapters. One was for a Wisco adapter. If you go to Wisco's website you can see that they offer a 300 series neck in several different styles. This leads me to believe that Aircraft Spruce gets their gas necks from Wisco. The one pictured in the Aircraft Spruce catalog looks like the 327 neck on Wisco's website. I'd call Spruce to confirm it's threaded then call Wisco to try and get a better price straight from the manufacturer. Is 2-5/16 X 18 NF the right thread to match the 170 tank?

I called Wisco regarding their zinc plated stainless filler necks. They can be special ordered with a chain anchor. $26 each with a minimum order of $150. Lead time is several months. The filler neck, Cessna p/n 0311240-17, is “not available” from Cessna. The steel filler neck from Aircraft Spruce is not FAA-approved nor is this stainless steel one from Wisco so a 337 field approval would be required in either case. Are there at least two others that would be interested in being part of group purchase? Send me a PM if interested. Get rid of the rust and get your fuel caps clocked straight!

[Ryan Smith]

Count me in, Gary.

[GAHorn]

Just curious why one wouldn’t order the Spruce caps…and “Quality Control Inspect/Modify” under Owner Produced parts…

…or I suppose since you are special ordering…simply include the instructions to “duplicate by reverse engineering” those you’re ordering and install them under OPP.. no 337 req’d.

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[n2582d]

Going to this much trouble to replace them, for a couple more buck, might as well get them made from stainless steel -- which is not available from ACS. Ryan's on the list --need one more order.