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safety wiring AN fitting nuts

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brianpublic2(at)starband.
Guest

Posted: Tue Dec 19, 2006 7:19 am Post subject: safety wiring AN fitting nuts

A kid recently asked me this question through EAA:



"Why aren't flare tube fittings and hose fittings safety wired?"



I have kinda wondered about this myself sometimes. I seem to vaguely recall that when I was a crew chief in the USAF in the early 70's that some AN fitting nuts were safetied, but I could be imagining it.



Does anyone have a good answer to this question?  I'd like to be able to answer this kid's question.



thanks,

brian

--

recapen(at)earthlink.net
Guest

Posted: Tue Dec 19, 2006 7:44 am Post subject: safety wiring AN fitting nuts

A recent Vans SB requires safety-wiring the AN fittings inside the fuel tank.



That doesn't answer the question though.....



My thoughts are that in order to get the fittings sealed, they require an amount of torque that can't be overcome by vibration.



Devil's advocate thought.....if the safety wire wasn't there, could the fitting loosen due to vibration....if the fitting were to loosen, what would be the result.  This line of thinking might cause you to safety everything - or think about it anyway......



My jarheaded thinking,

Ralph Capen

MGySgt USMC retired - A6's forever.......



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ronlee(at)pcisys.net
Guest

Posted: Tue Dec 19, 2006 7:57 am Post subject: safety wiring AN fitting nuts

At 08:19 AM 12/19/2006, you wrote:

 	  Quote: 	
		  



A kid recently asked me this question through EAA:



"Why aren't flare tube fittings and hose fittings safety wired?"



I have kinda wondered about this myself sometimes. I seem to vaguely 

recall that when I was a crew chief in the USAF in the early 70's that 

some AN fitting nuts were safetied, but I could be imagining it.



Does anyone have a good answer to this question?  I'd like to be able to 

answer this kid's question.



thanks,

brian


	




No answer but have you ever heard of one coming loose that was

installed properly?



Ron Lee



Do not archive

brianpublic2(at)starband.
Guest

Posted: Tue Dec 19, 2006 8:57 am Post subject: safety wiring AN fitting nuts

No, and I guess the idea is that safety wire probably won't keep it from

just loosening enough to leak, if it's going to loosen at all.  Maybe it's

just that "if properly torqued, they just don't loosen".   I don't know.

But then, couldn't we say this about many fasteners?   It's a very good

question.  Anyway, if someone does find out an answer, I'd like to be able

to get back to this kid with a good answer.

Thanks,

brian



--

jackanet(at)hotmail.com
Guest

Posted: Tue Dec 19, 2006 9:28 am Post subject: safety wiring AN fitting nuts

I was about to contact Van's with a similar query following three RV drivers 

inspecting my near completed -8, with one saying I needed safety wire the 

oil and fuel hoses to the pressure senders.  There's no way I can get at the 

engine attach ends to safety.  Similar imposibility, to finish drill the AN 

nuts, install, twist, and anchor safety wire, exists for the hoses to and 

from the oil cooler.

What gives?



Jack



 	  Quote: 	
		  From: Ron Lee <ronlee(at)pcisys.net>

Reply-To: rv-list(at)matronics.com

To: rv-list(at)matronics.com

Subject: Re: safety wiring AN fitting nuts

Date: Tue, 19 Dec 2006 08:56:05 -0700






At 08:19 AM 12/19/2006, you wrote:

>

>

>A kid recently asked me this question through EAA:

>

>"Why aren't flare tube fittings and hose fittings safety wired?"

>

>I have kinda wondered about this myself sometimes. I seem to vaguely 

>recall that when I was a crew chief in the USAF in the early 70's that 

>some AN fitting nuts were safetied, but I could be imagining it.

>

>Does anyone have a good answer to this question?  I'd like to be able to 

>answer this kid's question.

>

>thanks,

>brian

No answer but have you ever heard of one coming loose that was

installed properly?



Ron Lee



Do not archive




	


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jim jewell

Joined: 09 Jan 2006
Posts: 82
Location: Kelowna B.C. Canada

Posted: Tue Dec 19, 2006 10:10 am Post subject: safety wiring AN fitting nuts

I agree, the question is a good one.

May I suggest that you contact the manufacurer of the fitings and get the 

word direct from the horse's mouth so to speak. 



Jim in Kelowna

 ---

_________________
"I never make mistreaks"

Hopperdhh(at)aol.com
Guest

Posted: Tue Dec 19, 2006 12:14 pm Post subject: safety wiring AN fitting nuts

I'd be interested in knowing if anyone found their fuel fittings loose while complying with their "Mandatory Service Bulletin."  Mine were tight just like I left them.  Now, I could understand if someone left theirs loose, they may find them that way!

  

 I learned a lesson some time ago -- almost the hard way.  Never leave a hose fitting finger tight.  If you are not ready to tighten it, leave it completely disconnected.

  

 Dan Hopper

 RV-7A

  

  [quote][b]

ronlee(at)pcisys.net
Guest

Posted: Tue Dec 19, 2006 12:57 pm Post subject: safety wiring AN fitting nuts

 	  Quote: 	
		  I learned a lesson some time ago -- almost the hard way.  Never


	


 	  Quote: 	
		  leave a hose fitting finger tight.  If you are not ready to tighten it, 

leave it completely disconnected.


	


Excellent point Dan.  The same applies to a canopy while taxiing.



If these nuts were to be safety tied then there would be a "hole"

in them to accommodate safety wire.



Just my opinion.



Ron Lee

brianpublic2(at)starband.
Guest

Posted: Tue Dec 19, 2006 1:07 pm Post subject: safety wiring AN fitting nuts

Another trick I use throughout my plane is that all connections and fasteners get orange marking paint when they are torqued.  I even put it on the flats on my AN nuts.  Anything not marked with the orange paint (from Avery – p/n 125) is not considered tight and won’t pass the inspection  

brian  

<![if !supportEmptyParas]> <![endif]>  

--

Bob Collins

Joined: 11 Mar 2006
Posts: 470
Location: St. Paul, Minnesota

Posted: Tue Dec 19, 2006 1:38 pm Post subject: Re: safety wiring AN fitting nuts

I'm not altogether sure what I'd safety an AN fitting to in many cases. The SB was easy because there was an anti-rotation bracket there.  



When I opened my tank, my fitting in one wing was fine. But I'm glad for the SB because I'm pretty sure I didn't think to torque it properly.  The other fitting in the other  tank, when I opened it, was smothered with ProSeal, which taught me to ALWAYS take pictures of EVERYTHING for the log book.

_________________
Bob Collins
St. Paul, Minn.
Letters from Flyover Country
http://rvnewsletter.blogspot.com/

George McNutt

Joined: 09 Jan 2006
Posts: 30

Posted: Tue Dec 19, 2006 5:58 pm Post subject: safety wiring AN fitting nuts

Excellent lesson Dan, and from the same perspective, - never try to be 

helpful by starting the fittings for another person!



George In Langley BC

 	  Quote: 	
		    

 I learned a lesson some time ago -- almost the hard way.  Never leave 

 a hose fitting finger tight.  If you are not ready to tighten it, 

 leave it completely disconnected.

deanpichon(at)msn.com
Guest

Posted: Wed Dec 20, 2006 4:21 am Post subject: safety wiring AN fitting nuts

I am intrigued by this question, too.  I have rarely seen safety-wired AN 

flared fittings, but did find in the literature that the specification for 

the standard AN coupling nut (AN818) includes a drilled variant for safety 

wiring.  The drilled part is designated AN818-L(X) where L is the nominal 

size.



Also, Acceptable Methods, Techniques, and Practices -- Aircraft Inspection 

and Repair (AC No. 43.13-1B) includes several pages of recommended 

techniques for safety wiring these nuts.  Unfortunately, I could find no 

mention of when safety wiring is (or is not) required.



Regards,



Dean



----Original Message Follows----

From: "Brian Meyette" <brianpublic2(at)starband.net>

Reply-To: rv-list(at)matronics.com

To: <rv-list(at)matronics.com>

Subject: safety wiring AN fitting nuts

Date: Tue, 19 Dec 2006 10:19:00 -0500






A kid recently asked me this question through EAA:



"Why aren't flare tube fittings and hose fittings safety wired?"



I have kinda wondered about this myself sometimes. I seem to vaguely recall 

that when I was a crew chief in the USAF in the early 70's that some AN 

fitting nuts were safetied, but I could be imagining it.



Does anyone have a good answer to this question?  I'd like to be able to 

answer this kid's question.



thanks,

brian

--



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LessDragProd(at)aol.com
Guest

Posted: Wed Dec 20, 2006 8:30 am Post subject: safety wiring AN fitting nuts

Hi All,

  

 I have had the benefit of having the help from an aerospace A&P  mechanic for a couple of decades.  There is an  aerospace specification that applies to flare tube fittings in a  fuel tank.

  

 The preferred method of retention for the flare tube fitting in a fuel tank  is to use tank sealer.  It needs to be at least .150" thick for at least  .250" on the flare tube nut and .250" across onto the flare tube  fitting.  

  

 I haven't mentioned this before, because it is not an option provided by  the design organization, Van's Aircraft.

  

 Regards,

 Jim Ayers

  

 In a message dated 12/20/2006 4:23:52 AM Pacific Standard Time,  deanpichon(at)msn.com writes:

  	  Quote: 	
		     --> RV-List message posted by: "Dean Pichon"    <deanpichon(at)msn.com>



I am intrigued by this question, too.     I have rarely seen safety-wired AN 

flared fittings, but did find in the    literature that the specification for 

the standard AN coupling nut (AN818)    includes a drilled variant for safety 

wiring.  The drilled part is    designated AN818-L(X) where L is the nominal 

size.



Also, Acceptable    Methods, Techniques, and Practices -- Aircraft Inspection 

and Repair (AC    No. 43.13-1B) includes several pages of recommended 

techniques for safety    wiring these nuts.  Unfortunately, I could find no 

mention of when    safety wiring is (or is not)    required.



Regards,



Dean



	


 

  

  [quote][b]

michele.delsol(at)microsi
Guest

Posted: Thu Dec 21, 2006 7:58 am Post subject: safety wiring AN fitting nuts

On the same score, if you torque down a nut or bolt, put some paint on it immediately. Any bolt/nut not marked as having been torqued down should be torqued down. So, when you inspect your work you should not have to ask yourself, did I torque this bolt down or not.  

   

Sounds elementary, but it is one of those little things which can make a lot of difference.  

   

Michèle  

RV8 - Finishing  

         

  

From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Hopperdhh(at)aol.com

 Sent: mardi 19 décembre 2006 21:14

 To: rv-list(at)matronics.com

 Subject: Re: safety wiring AN fitting nuts  

  

     

I'd be interested in knowing if anyone found their fuel fittings loose while complying with their "Mandatory Service Bulletin."  Mine were tight just like I left them.  Now, I could understand if someone left theirs loose, they may find them that way!  

    

   

    

I learned a lesson some time ago -- almost the hard way.  Never leave a hose fitting finger tight.  If you are not ready to tighten it, leave it completely disconnected.  

    

   

    

Dan Hopper  

    

RV-7A  

    

   

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       [quote][b]

Ed Anderson

Joined: 10 Jan 2006
Posts: 475

Posted: Thu Dec 21, 2006 8:29 am Post subject: safety wiring AN fitting nuts

Having had the AN nut on my "Flop tube" in the right tank  come loose after 160 hours of flying with the resulting disconnect of the tube -  which meant the last 3 1/2 gallons of fuel were not assessable - I agree.   Don't put a hose/tube on a fitting unless you are going to tighten it to specs  at that time - otherwise leave it off.   I don't know - but I  strongly suspect that my fitting was only on "finger tight" and eventually  worked loose.

  

 Ed

  

 Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews,  NC

eanderson(at)carolina.rr.com (eanderson(at)carolina.rr.com)

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.dmack.net/mazda/index.html

 [quote]   ---

_________________
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com

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