acceptable use of a safety wire: in place of a hose clamp?

bavreze

bavreze

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bavareze
hi guys!

I'm having a little problem with a plane mechanic. he replaced this airbox and, for some reason, the airbox that he sourced has a shorter pipe and therefore he was unable to secure the alternate air intake hose with a clamp, so instead he caught it with 2 zip ties. After some controversy, he removed the zip ties and he wrapped some safety wire around it and around the metal air duct part and made it hold together, kinda loose though.

I told him the air box was bad and we needed a new one but he tried to convince me that he knew what he was doing and this was an acceptable use of a safety wire, and even showed me in the FAA book (the FAA book shows no hose fitting use, but another circular part with a clip). And also he found some pictures online, see the one with the hose around a pipe.

Now, I am no experienced mechanic but I pulled the air hose and it came off pretty easily and I kinda see a situation where that hose becomes loose in a flight and touches my exhaust manifold and then I have a fire or some foreign object gets ingested in the intake manifold.

He told me I am a picky customer and I know nothing about older planes, and that he has 3 or 4 A&P ready to confirm that his setup was standard. I do not want to be that trouble maker customer but I've read so many crash reports where a dubious repair caused a big mess, so I am posting this here to hear from other people.

When responding please also mention your qualification (i.e. back alley mechanic who has seen a lot, a&p, IA etc) so I can understand better where I am.

Thanks!
 

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The drawing in the manual is an external ring that is secured with a piece of safety wire. Not safety wire all the way around. The small hose pictured is something I have seen before. The picture of your scat hose is unacceptable in my opinion.

A&P
 
if you think it sucks just think what his local fisdo would think! however there was more suckage in the photos than his handiwork! the airbox and everything else looks like sh.. . wtf you need to fix that aircraft and not spend time on the interwebs. btw ask the mods for a delete on this thread .your liability is huge .
 
hotprops said:
if you think it sucks just think what his local fisdo would think! however there was more suckage in the photos than his handiwork! the airbox and everything else looks like sh.. . wtf you need to fix that aircraft and not spend time on the interwebs. btw ask the mods for a delete on this thread .your liability is huge .
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This seems like an over reaction to me. What possible liability issues are there here for the poster? What else is wrong specifically? Looks like every older mooney I've ever seen.
 
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Overreacting is common on this forum, but most of the time it isn't A&P techs that get excited.

In a kinda ho-hum manner, tarheelpilot says the "scat hose is unacceptable in my opinion".

And that's that.

I suspect the construction methods used to assemble the airbox proper may have caused him to take a second look, but since he wasn't asked about it he didn't offer an opinion.

Tarheelpilot's attention to the question and laconic yet specific judgement while ignoring other questionable items in the photo keep down the drama and gives the OP the info he needs to have the repair done correctly or perhaps the impetus to find a more discerning mechanic.

I like that style. No one's hair was set on fire while making this thread.

Qualifications: Not an A&P but years of experience in pro level (IndyCar) racing and therefore ultimately responsible for driver's and vehicle's safety.
 
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3393RP said:
Overreacting is common on this forum, but most of the time it isn't A&P techs that get excited.

In a kinda ho-hum manner, tarheelpilot says the "scat hose is unacceptable in my opinion".

And that's that.

I suspect the construction methods used to assemble the airbox proper may have caused him to take a second look, but since he wasn't asked about it he didn't offer an opinion.

Tarheelpilot's attention to the question and laconic yet specific judgement while ignoring other questionable items in the photo keep down the drama and gives the OP the info he needs to have the repair done correctly or perhaps the impetus to find a more discerning mechanic.

I like that style. No one's hair was set on fire while making this thread.

Qualifications: Not an A&P but years of experience in pro level (IndyCar) racing and therefore ultimately responsible for driver's and vehicle's safety.
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I agree, which is why I "liked" his post.
 
It would concern me. Not an A&P, but a lot of relevant experience, and operating under the influence of some pretty good ones.

Were it my plane, I would try to source a better air box or, failing that, might try showing off some good sheet metal mojo and fabricate an appropriate extension to the throats in question.

But that's me.
 
And that's a reasonable reaction. I get the feeling if the OP's aircraft continued to be kept under the repair and maintenance protocols illustrated by the barely-hanging-on scat hose it wouldn't be long before the aircraft would become a hodgepodge of barely connected parts, flying in a loose formation over the San Fernando Valley or San Gabriel Mountains.

OP, don't be afraid to speak up about the manner in which maintenance is addressed on your aircraft. You are smart enough to know what good work looks like and when poor work should be rejected.

If you have other airplanes in hangars around yours, don't be afraid to introduce yourself and take a look at other aircraft when their cowlings are removed. Most pilots are happy to share knowledge.
 
Safety wire as a hose clamp for small hoses (the blue hose in your picture) is fine, I've done that a lot (on ultralights, though). I actually prefer safety wire to clamps on the soft urethane hose like the blue stuff. The zip ties on the scat hose I don't like, they can't be tightened enough to properly secure the wire reinforced duct.

Not an A&P, just worked on a lot of planes.
 
I would probably, who am I kidding I would and have, done something like that on a repair on my truck but an airplane I think I would find a more skookum solution. That looks more like an "I need to get it home and this will work for the trip" solution than a long term repair.
 
Dana said:
Safety wire as a hose clamp for small hoses (the blue hose in your picture) is fine, I've done that a lot (on ultralights, though). I actually prefer safety wire to clamps on the soft urethane hose like the blue stuff. The zip ties on the scat hose I don't like, they can't be tightened enough to properly secure the wire reinforced duct.

Not an A&P, just worked on a lot of planes.
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I be afraid that the wire would cut the hose, given all the vibration the engine and it's connected parts. If you can get safety wire on it you can get a hose clamp. BTW, they have thinner hose clamps if necessary.
By comparison, on my boat all hoses are secured with 2 hose clamps, I was shocked the first time I look at a plane and saw only single clamps.
 
If wild Zulu with spears were chasing me down, it would do to get off the ground. Otherwise I'd have it done the proper way.
 
Meh...seen it before, but wouldn't want it on my plane (and if my mechanic did it I would just tell him to change it...and also remind him that I'm paying the bill for it to be done the way I'm comfortable with). Then I'd move on.
 
ok guys, thanks for the responses. I have decided to reject this job and source better airbox.
 
Interesting that you favor unqualified internet responses to photos over the opinion of the hands-on mechanic who is the most qualified info source you have available.
 
If this were a remote field, get her home, patch job I'd probably accept it.

But I would never accept such "house of mouse" repair as permanent in any of the planes I own. Period.

Not a mechanic - Own 1 plane outright and 2 in partnership.
 
Inelegant.
But not likely to bring down the ship.
 
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Tarheelpilot said:
The drawing in the manual is an external ring that is secured with a piece of safety wire. Not safety wire all the way around. The small hose pictured is something I have seen before. The picture of your scat hose is unacceptable in my opinion.
A&P
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You are correct. **** the naysayers.
 
Stewartb said:
Interesting that you favor unqualified internet responses to photos over the opinion of the hands-on mechanic who is the most qualified info source you have available.
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Let me guess, said mechanic would never admit in writing that he secured the duct with only safety wire.
 
The maintance manual will show how it is to be assembled. If it's not put together that way it's not right. Period.

Bob
 
Stewartb said:
Interesting that you favor unqualified internet responses to photos over the opinion of the hands-on mechanic who is the most qualified info source you have available.
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I bet you stick said mechanic's name on this thread along with those photos and their "professional" opinion about their own mediocre work, changes dramatically.
 
GlennAB1 said:
Illustrated Parts Catalog (IPC), there may be other terms, Illustrated Parts Bulletin (IPB), etc., real aircraft have them.
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Thanks. Didn't know what IPC stood for, was just asking. I also didn't know that an IPC specified anything other than parts and part numbers. Learn something new daily, I suppose.

You live in a 121 world. I gather you don't deal much, if at all, in the 91 world. Just because our airplanes may not have manuals as detailed as the 121 outfits, that does not mean our airplanes are any less real. Most of us on this board live in that part 91 world and frankly, some of your comments are not at all endearing to some (most?) of us.

If I misread the tone of your comment, please forgive me.
 
Greg Bockelman said:
Thanks. Didn't know what IPC stood for, was just asking. I also didn't know that an IPC specified anything other than parts and part numbers. Learn something new daily, I suppose.

You live in a 121 world. I gather you don't deal much, if at all, in the 91 world. Just because our airplanes may not have manuals as detailed as the 121 outfits, that does not mean our airplanes are any less real. Most of us on this board live in that part 91 world and frankly, some of your comments are not at all endearing to some (most?) of us.

If I misread the tone of your comment, please forgive me.
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I know that the A&P IA that I use tries to make the airplane look like the picture in the book. Sometimes the picture maybe wasn't updated or the the parts aren't quite to spec. Mostly plastic and composite parts vary but some aluminum in there as well. At least all the big parts seem to fit right.
 
Greg Bockelman said:
Thanks. Didn't know what IPC stood for, was just asking. I also didn't know that an IPC specified anything other than parts and part numbers. Learn something new daily, I suppose.

You live in a 121 world. I gather you don't deal much, if at all, in the 91 world. Just because our airplanes may not have manuals as detailed as the 121 outfits, that does not mean our airplanes are any less real. Most of us on this board live in that part 91 world and frankly, some of your comments are not at all endearing to some (most?) of us.

If I misread the tone of your comment, please forgive me.
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Sorry. There are plenty of examples of pilots ribbing other pilots about not being real pilots based on what they fly. Fighter jocks vs. Transport category, fixed wing vs rotary wing.
You're a part 91 Airline Pilot?
 
GlennAB1 said:
You're a part 91 Airline Pilot?
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LOL. I like to say that I am a General Aviation pilot who happens to fly big airplanes for a living as opposed to an airline pilot that happens to fly little airplanes occasionally. There is a difference.

As to your other comment, you have a point there. It is sometimes hard to determine context by the written word.
 
OBTW: Greg: If you see a missile coming, DUCK!
 
Greg Bockelman said:
If I misread the tone of your comment, please forgive me.
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You didn't. It's repetitive and negative.

Greg Bockelman said:
As to your other comment, you have a point there. It is sometimes hard to determine context by the written word.
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It's pretty clear when someone continually uses statements like "real airplanes" regularly, that they're being condescending.

Written word in that case makes it quite clear. He could just as easily say, "more heavily regulated airplanes certified under completely different rules than yours". Or similar. Shorten it to "airliners", we all know what that means.

Meanwhile, "airliner" maintenance practices aside, I still think that "repair" with a tie-wrap sucks. :)
 
denverpilot said:
You didn't. It's repetitive and negative.



It's pretty clear when someone continually uses statements like "real airplanes" regularly, that they're being condescending.

Written word in that case makes it quite clear. He could just as easily say, "more heavily regulated airplanes certified under completely different rules than yours". Or similar. Shorten it to "airliners", we all know what that means.

Meanwhile, "airliner" maintenance practices aside, I still think that "repair" with a tie-wrap sucks. :)
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3,857 posts in almost 2 years and 3 posts reference "real airplanes" so "continually" is more than an exageration.
 
GlennAB1 said:
3,857 posts in almost 2 years and 3 posts reference "real airplanes" so "continually" is more than an exageration.
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It's ok. Other posts about maintenance issues are scattered with similar wording. We know nobody does it better than the airlines. You're good at reminding all of us.

And you're probably right. And it's probably a good thing. But it's completely out of touch with what happens at the lower levels.

It happens in every industry. The low end doesn't have the resources nor the level of oversight to be able to do it the way an airliner shop does it.

Mostly that means those of us flying the small stuff have to be extra vigilant for stupidity under the cowl when we look. And know which mechanics won't cut corners.

Or alternatively some rental places seek out the ones who will. Signature still looks the same in the aircraft logs to the unaware pilot.

I bet there's nobody here who hasn't had to hand the keys right back to the mechanic straight out of an annual inspection because something is wrong. Or right after a squawk was supposedly fixed. Doesn't probably happen much in your world. We know. We know very well.

That's probably what makes it so grating. We'd happily let a 20 person team crawl all over the airplanes, with perfect manuals and procedures written for everything, if the economics allowed. It never will.

About all we can do is buy the airplane and stay on top of what we see "the best mechanic in town" does to it. Some are great, some suck. At home you get a choice. Break down on the road, roll the dice.
 
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