Cessna Rigging

JAWS said:
FAR 43.9 is maintenance records. 43.13 is maintenance performance. Are you trying to say that FAR 43.13 is not required, even for a simple cowl patch? :rolleyes:
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Not at all.. read the rule.

I should add, reference not required, in the return to service entry.
a simple statement of work is all that is needed.

"" repaired cracked cowling ""
 
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JAWS said:
And Cessna would like you to buy engine oil and filters and screws and light bulbs from them too. What about the SIDS inspections that Cessna wants done? What about service bulletins?

The FAA makes the rules, not Cessna.
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Exactly. and Cessna uses those rules to their best advantage.
A SBs, SIBs are not a maintenance manuals.

Cessna placed that statement in their manual just as a CYA thing, When the accident happens they will avoid responsibility by simply saying the A&P/or ? did not our get data to repair yada yada.
When you ask the FSDO for a field approval and base it on the AC43.? page and para. it will be denied for lack of Cessna, (OEM) data.
I deal with antique and classic aircraft that have no pubs, the 43,13 data is readily accepted in these cases.
 
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Tom-D said:
When you ask the FSDO for a field approval and base it on the AC43.? page and para. it will be denied for lack of Cessna, (OEM) data.
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337 not approved? Maybe in your end of town, but not with the FSDO/MIDOs I've dealt with. Maybe your FSDO simply prefers the SRM method. It's definitely easier in most cases to use the SRM methods but there is no FAA hierarchy between the Cessna SRM and AC43-13. They're both acceptable data as stated above.

Even if the Cessna SRM was an FAA-Approved document you still have the option of using the AC. I've seen it go various ways regardless of data used. I personally believe it depends on the PMI, complexity of repair, what he ate for lunch, and the moon phase.

But to each their own. It's your certificate and opinion. However, to emphatically state one method is required over another when there is established FAA guidance to the contrary is not correct either.
 
Bell206 said:
337 not approved? Maybe in your end of town, but not with the FSDO/MIDOs I've dealt with. Maybe your FSDO simply prefers the SRM method. It's definitely easier in most cases to use the SRM methods but there is no FAA hierarchy between the Cessna SRM and AC43-13. They're both acceptable data as stated above.

Even if the Cessna SRM was an FAA-Approved document you still have the option of using the AC. I've seen it go various ways regardless of data used. I personally believe it depends on the PMI, complexity of repair, what he ate for lunch, and the moon phase.

But to each their own. It's your certificate and opinion. However, to emphatically state one method is required over another when there is established FAA guidance to the contrary is not correct either.
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Yep! Nice to see that someone gets it! :) I use AC43.13 sometimes, the SIRM others - depends on what the job is.

Here is a nice write up and a few pictures of a similar area in question.

http://www.cessna170.org/forums/viewtopic.php?f=24&t=10163

The original poster is asking the right questions and sounds like he has the right attitude. Also nice to see.
 
In your cover letter requesting a field approval, tell the ASI that Cessna says to do it one way but you want to do it IAW the 43,13.
see if they approve it.
 
JAWS said:
Y
The original poster is asking the right questions and sounds like he has the right attitude. Also nice to see.
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Yep, he will get the supervision he needs from the only one who counts. betcha.
 
Something to ponder. Whether you dig into the flight control rigging or the fuel tanks, just be prepared for the "surprises" that will come up. You might wind up having to reskin ailerons, or repair the horizontal stab forward attachment (years of pushing down on the tail), or replace cables, or, etc, etc.

Cessna has specialists that know the pitfalls of each model and how to properly get your plane rigged for best performance. Unless you have the time and ability to start checking items yourself.

Something to get started with.

http://cessnaowner.org/magazine/the-right-way-to-rig-a-crooked-flying-plane/

Edit: Should read above "There are Cessna rigging specialists around. The Cessna Pilots Association has a list of individuals."
 
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Tom-D said:
A Hat Section is an aluminum channel that is riveted to the bottom skin of the wing, that support the tank.
url
The rubber that you linked is the protection for the tank that is placed on the hold down straps on top of the tank.

the hat section usually simply have a felt strip glued to the hat section to prevent chafing. they sell the felt in most hardware stores as insolation.
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Cessna wants the rubber on the bottom, too. No felt. I have never seen felt there. The OP's problem is likely partly that the rubber is gone and the tank is sitting on the hat sections. I will look it up tomottow.
 
Tom-D said:
A Hat Section is an aluminum channel that is riveted to the bottom skin of the wing, that support the tank.
url
The rubber that you linked is the protection for the tank that is placed on the hold down straps on top of the tank.

the hat section usually simply have a felt strip glued to the hat section to prevent chafing. they sell the felt in most hardware stores as insolation.
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Duplicate
 
Tom-D said:
In your cover letter requesting a field approval, tell the ASI that Cessna says to do it one way but you want to do it IAW the 43,13.
see if they approve it.
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I guess you missed my comment in the last post. Already have in the past, but I would usually meet the ASI in person first. Even had one ASI not accept SRM data on face value and had to contact OEM to get letter. No problem but cost a little more. Most ASIs prefer SRM data because their 8900-1 guidance states the SRM is preferred because the data doesn't need to be "re-approved" even if the SRM manual itself is not FAA-approved. So most ASIs won't "extend" themselves. But no where in the 8900 does it state the SRM overrules other available data. I've never had major issues with the various types of data I used on field approvals, but YMMV.
 
Dan Thomas said:
Cessna wants the rubber on the bottom, too. No felt. I have never seen felt there. The OP's problem is likely partly that the rubber is gone and the tank is sitting on the hat sections. I will look it up tomottow.
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but it is a different rubber than he posted. what he posted is for the top straps. the bottom is flat and glued in. the C-175 came with felt.
 
Bell206 said:
I guess you missed my comment in the last post. Already have in the past, but I would usually meet the ASI in person first. Even had one ASI not accept SRM data on face value and had to contact OEM to get letter. No problem but cost a little more. Most ASIs prefer SRM data because their 8900-1 guidance states the SRM is preferred because the data doesn't need to be "re-approved" even if the SRM manual itself is not FAA-approved. So most ASIs won't "extend" themselves. But no where in the 8900 does it state the SRM overrules other available data. I've never had major issues with the various types of data I used on field approvals, but YMMV.
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I'll not argue this at nauseam, Because FSDOs are maned by humans, and my ASI has reminded me that they have guidance to not approve data when there is manufacturers approved methods to get the repair done.
And the Cessna SRM is pretty explicit about, If it ain't here, call us.
When I manufactured new Spars for a friends Fairchild 24 We could not find a spar blank large enough to cut a new one. I submitted a field approval to laminate the blank from smaller strips of spruce.
My ASI returned the package, wanting to now spec on the glue used, I supplied that, smoothed the cover letter and sent it In again he then approved it.
 
Dan Thomas said:
Cessna wants the rubber on the bottom, too. No felt. I have never seen felt there. The OP's problem is likely partly that the rubber is gone and the tank is sitting on the hat sections. I will look it up tomottow.
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When you look at the PIB it shows the rubber on the straps, (fig -7 & 8) view the bottom in Fig-3, it does show Item #12 to be a "pad neoprene"
 
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Tom-D said:
When you look at the PIB it shows the rubber on the straps, (fig -7 & 8) view the bottom in Fig-3, it does show Item #12 to be a "pad neoprene"
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That's what my current copy shows. Neoprene strip. Cessna has changed up the number a couple of times and now it's a bulk item, R881203, and is only about 1/16" thick. The old green stuff was around 1/8".
 
Dan Thomas said:
That's what my current copy shows. Neoprene strip. Cessna has changed up the number a couple of times and now it's a bulk item, R881203, and is only about 1/16" thick. The old green stuff was around 1/8".
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Thanks for the part number, i was having trouble tracking this down. a little bit confused because it would seam that my tank is sitting more than 1/16 or 1/8" low, so i wonder if i have another problem aside from the pad being worn thin. Only one way to find out.
 
alexl said:
Thanks for the part number, i was having trouble tracking this down. a little bit confused because it would seam that my tank is sitting more than 1/16 or 1/8" low, so i wonder if i have another problem aside from the pad being worn thin. Only one way to find out.
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Just remember, rubber decays, felt never does. :)
 
Tom-D said:
Just remember, rubber decays, felt never does. :)
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Tom - there seams to be some question on whether this strip should be felt or rubber, and whether it is legal or acceptable to use one or the other. It is apparent that the parts catalog lists the pad as being neoprene. However, i also know that just because neoprene was selected as the service part, does not mean that the factory part was the same. I do this every day (subbing out different service parts which are acceptable in place of the original).

Just so i am clear, you would opine that something like this would be acceptible to use:
http://www.acehardware.com/product/index.jsp?productId=68347416
 
That's what I use.
 
alexl said:
Tom - there seams to be some question on whether this strip should be felt or rubber, and whether it is legal or acceptable to use one or the other. It is apparent that the parts catalog lists the pad as being neoprene. However, i also know that just because neoprene was selected as the service part, does not mean that the factory part was the same. I do this every day (subbing out different service parts which are acceptable in place of the original).

Just so i am clear, you would opine that something like this would be acceptible to use:
http://www.acehardware.com/product/index.jsp?productId=68347416
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I believe some civil lawyer could make a case of not using the latest version of the part.
I don't believe the FAA ever would.
The only precaution would be, not to place too much in, there is a limit to how much the upper strap can reach.
 
alexl said:
whether it is legal or acceptable to use one or the other
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FYI: felt/rubber fall under standard parts and substitution in this install should be no problem. If you have any second thoughts about using the felt call it a minor alteration, make entry, and be done with it. And as mentioned above felt lasts a long time.

If you need a denser or thicker felt than what you referenced above, look for a S.A.E. Pressed Wool Felt. It comes in various colors, thicknesses and densities. It's a bit pricier but I have used it to make replacement bearing grease gaskets, chafe strips, vibration absorbers, etc.
 
JAWS said:
But Cessna wants a specific neoprene part, not felt. Hmmmm? o_O
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Felt will let the tank slide around a small bit in slips or skids, and that places strain on the filler neck assembly and vent and fuel outlets, and chafing against the straps will occur especially if the neoprene is gone off them.

Cessna specifies felt around the edges of the windshield so that it will slip. The airframe flexes in flight, and temperature variations expand and contract it, and if the windshield was bonded or clamped in tightly it would crack. You might hear it squeak some when starting the engine and the firewall twists everything a bit.

I have seen that the adhesive holding the neoprene often ages and lets go before the rubber itself is shot. Felt would suffer the same thing, and self-stick felt would not stay put long at all. Pulling old tanks out you will find the old strips laying in the areas between the hat sections. The glue failed and they worked their way out. The tank then chafes against the aluminum hat sections.
 
I have never seen felt slip in the way Dan says it does. The 170 that I restored was a 48 the tanks had been in since day 1, they were set on felt, no glue, and were as good as new.
Put some gas on a neoprene rubber strip and see how slippery it gets, On felt it does not get slippery.
most of the A&Ps will glue the rubber in place using contact cement, fuel resolves it, so as soon as you have any leak, the whole assembly comes apart.
I lay the felt in epoxy, on clean and treated aluminum. it stays put.
 
Dan Thomas said:
Felt will let the tank slide around a small bit in slips or skids, and that places strain on the filler neck assembly and vent and fuel outlets, and chafing against the straps will occur especially if the neoprene is gone off them.

Cessna specifies felt around the edges of the windshield so that it will slip. The airframe flexes in flight, and temperature variations expand and contract it, and if the windshield was bonded or clamped in tightly it would crack. You might hear it squeak some when starting the engine and the firewall twists everything a bit.

I have seen that the adhesive holding the neoprene often ages and lets go before the rubber itself is shot. Felt would suffer the same thing, and self-stick felt would not stay put long at all. Pulling old tanks out you will find the old strips laying in the areas between the hat sections. The glue failed and they worked their way out. The tank then chafes against the aluminum hat sections.
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When you install a tank in properly, tighten the straps properly, it will not slip.
Felt is a organic substance (wool) fuel does not effect it, it will not get slippery and move around.
Windshields are a whole different structure, it is allowed to slip to relieve stresses that would crack it.
 
Quick update

It appears the tank has collapsed in the past due to a clogged vent possibly. Someone tried to “fix” the issue with compressed air, which of course made the tank into a balloon and caused it to swell. Sourcing a replacement tank now.

Alex
 
Hilarious! (the-blow-it-up-to-fix-it technique)
Thanks for returning to report.
 
Tom-D said:
When you install a tank in properly, tighten the straps properly, it will not slip.
Felt is a organic substance (wool) fuel does not effect it, it will not get slippery and move around.
Windshields are a whole different structure, it is allowed to slip to relieve stresses that would crack it.
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Tom- something doesn't follow in your statements. Both wool and neoprene are "organic" substances. By the logic above, neither should be affected by fuel. Felt in general may be made from a variety of fibers, not just wool. Please consider rewording your statement to reflect the meaning you intend.
 
Final Update:

The tank was replaced and the airplane fully re-rigged. Airplane now flies hands off, about 8-10 knots faster and the door no longer interferes with the fuel sump. Both wings appear to be very close to neutral position. I am very pleased with the results.
 
So...curious...who'd you have rig it?

Whoever it was, it sounds like they did a great job!
 
Funny how proper maintenance fixes stuff, Goodonya!
 
alexl said:
Mr. Richard Kaczmarek out of Sandersville
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I know him! (I think)

Has he been there for a dozen years or more? And does he build/help people Build RVs? If so, I know that guy! I came close to buying an RV from him when I was down there.

Great guy, if that's him, I got to know him when I was building an O'Reilly in Sandersville and rented a hanger there.
 
Wow i have the same exact problem! Notch cut at top of pilot door and drain considerably lower than co pilot side drain. Ill add that my plane cruises uncoordinated with ball to the right. I try to hold the ball center but my foot gets tired. Im also burning way more fuel from left tank during cruise. I mean it will almost go to empty before fuel starts being fed from right tank.
 
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