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Hartzell prop safety wire

Mel

Legacy Member
Mentor
I continue to find safety wire on Hartzell C/S prop hubs pulled across the webs.

Over time, with vibration, the safety wire can wear into the web. When this happens, the prop hub is destroyed and is not repairable. My recommendation is to cover the safety wire with something like nylaflo tubing as an anti-chafe.

While this is NOT a requirement, it is a strong recommendation.
 
I continue to find safety wire on Hartzell C/S prop hubs pulled across the webs.

Over time, with vibration, the safety wire can wear into the web. When this happens, the prop hub is destroyed and is not repairable. My recommendation is to cover the safety wire with something like nylaflo tubing as an anti-chafe.

While this is NOT a requirement, it is a strong recommendation.

Like this?

20200803_124553 by Jereme Carne, on Flickr
 
Hartzell also says only req'd if called out in the AC Mntc manual, which we don't have, so safety wire is optional.
Personally I prefer not to waste my time installing it. Check torque each CI which is better way to determine security, a sheared bolt/stud cannot be determined by just looking at safety wire or torque seal. I like to check torque on all critical fasteners of which there are many on the RV.
 
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Gentlemen, thank you. I had no idea…

Different discussion that perhaps Mel can elaborate on but talk to your DAR early about safety wire size too. Some DARs are absolutely fixated on it being 0.041” even though as Walt points out in the manual it’s not required for us. I personally find I can do a much better job with 0.032” so that’s what I used.
 
Thanks for the heads up

Thanks for the note, I recently sent in my prop and installed it after getting it back looking new again.

Quick question, what size safety wire are you using? I've heard different things and want to make sure it is correct.

Looking again in my Hartzell manual it says to use .032 stainless safety wire minimum. Do you guys recommend wrangling with larger wire?
 
Thanks for the note, I recently sent in my prop and installed it after getting it back looking new again.

Quick question, what size safety wire are you using? I've heard different things and want to make sure it is correct.

Looking again in my Hartzell manual it says to use .032 stainless safety wire minimum. Do you guys recommend wrangling with larger wire?

See my post above. We were typing at the same time. :)
 
Like Mel says - if you get a picky overhaul shop and there is a mark on the web, you might be buying a new hub! And like Walt says, Hartzell doesn’t require you to safety wire at all - but it is hard to break habits of generations. When I was testing props earlier this year, and set a record of mounting three different props in one day on the same airplane, I have torqued them properly and not wired them….but when the prop is going top stay on, I sleep better if it is safetied.

Now that I am using the Safe-T-Cable system, it takes about five minutes to safety the whole prop….if time is money, the tool and cables aren’t that expensive…..

Paul
 
As for me -- I'll safety wire the prop bolts...

I'm with you Paul -- Not only sleep better, but worry less during flight.

Just thinking about various threads that have been running around here about build quality, attention to detail -- I don't think it's a good idea to leave safety wire off just because the propellor book says to see the airplane book and then make the inference and logic leap that it's OK to leave it off because the airplane book doesn't exist...

If it's got a hole in it, it needs to be filled with safety wire. Oh - and run the safety wire through a bit of nylon tubing so it doesn't rub on anything...expensive...
 
Now that I am using the Safe-T-Cable system, it takes about five minutes to safety the whole prop….if time is money, the tool and cables aren’t that expensive…..

Paul

I found a price on the .040 DMC Safe-T-Cable tool (DMC website) of US$450 compared to the deluxe Milbar safety wire pliers on ACS of US$78. Are there less expensive Safe-T-Cable tools that "aren't that expensive..."
 
Now that I am using the Safe-T-Cable system, it takes about five minutes to safety the whole prop….if time is money, the tool and cables aren’t that expensive…..

Paul

I agree, the Safe-T-Cable system is great. :cool: Thanks to this thread, the next time the spinner is off I will resecure with a bit of tubing, and the thought of doing it is not so daunting.
 
The Propeller Owner's Manual that came with my Hartzell compact hub constant speed propeller has very clear instructions on how to install the prop depending on whether it is a "F", "L", "K", "R" or "N" flange.

Some require safety wire, some don't.

Torque values differ by flange type and nut size.

My prop does not require safety wire. But I did it anyway.
 
I found a price on the .040 DMC Safe-T-Cable tool (DMC website) of US$450 compared to the deluxe Milbar safety wire pliers on ACS of US$78. Are there less expensive Safe-T-Cable tools that "aren't that expensive..."

Unfortunately, the only way to get the Safe-T-Cable tool cheaper is to look for a used one. It’s definitely a luxury tool, but if you do enough props, and you add up the time it takes to safety wire, and that time has value (other than the pure joy of working on your airplane), then it MIGHT make sense.

Or not….and that’s the beauty of luxury items - sometimes you just want one….
 
I found my Safe-T-Cable tool on e-bay, relatively cheap (~$250). Anecdotally, it is among the tools acquired (required?) when working overseas (?) and shed when the need is over. :rolleyes:
 
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