C/S Prop Nuts..safety wired?

[Rick6a]

Always learning. Unfamiliar with arcane constant speed propeller maintenance procedures, I did not realize that the 6 prop nuts are *sometimes* safety wired. I say "sometimes" because my official Hartzell Propeller Owners Manual says in part the following: : "Safety wire the studs in pairs (if required by the aircraft maintenance manual)" and found elsewhere in the same manual: " "Cut and remove the safety wire (if installed) on the propeller mounting stud nuts."

From what I gather, for experimental purposes, safety wiring the prop stud nuts seems to be an elective. What gives? Comments?

[L.Adamson]

It's listed somewhere but I'd have to look it up. As I remember, the .40 wire is called for. I originally went with the thinner wire, because I saw that listed too. I changed it, after harassment from someone.

edit: I don't know about elective, but every Hartzell C/S that I've seen, is wired.

L.Adamson --- RV6A

[Dan Blumel]

Originally Posted by Rick6a

Always learning. Unfamiliar with arcane constant speed propeller maintenance procedures, I did not realize that the 6 prop nuts are *sometimes* safety wired. I say "sometimes" because my official Hartzell Propeller Owners Manual says in part the following: : "Safety wire the studs in pairs (if required by the aircraft maintenance manual)" and found elsewhere in the same manual: " "Cut and remove the safety wire (if installed) on the propeller mounting stud nuts."

From what I gather, for experimental purposes, safety wiring the prop stud nuts seems to be an elective. What gives? Comments?

It MAY be a legal elective for experimentals but I would say only a fool (or uninformed) would NOT safety wire these bolts.
Your life depends on the prop working and most of all for CG reasons remaining on the aircraft even if it quits functioning correctly.
If the prop hub comes off the plane (with its associated blades) you will quite possibly move the CG far enough back to have a non flying "glider" on your hands. There is also at least a small posibility depending on how the hub departs the airplane, the vibration could also take the engine (tear it off the mounts) along with the hub and prop, before you get the engine shut down.

I may be over-reacting on this but I cannot imagine why anyone would consider to not safety wire the prop hub bolts. It is a PITA however to use the prefered larger wire and removal as well. It should be done in pairs otherwise what is the safety wire tied to.

[AZtailwind]

Originally Posted by Rick6a

From what I gather, for experimental purposes, safety wiring the prop stud nuts seems to be an elective. What gives? Comments?

I would say -safety wire when in doubt- I usually see the wire threaded all the way through each nut as opposed to the three pairs.

[Walt]

I don't safety wire my CS prop.

But, I am also an anal maintenance guy and R/R my prop once a year and throw a wrench on the bolts during regular maintenance to check them (I have never found them loose or under torqued). However, if you're the kind a guy that never spends time under the cowl just for fun checking things then by all means safety them.

The wife and I went flying yesterday and she made the comment "you did a great job building the plane honey and you take good care of her, going on 6 years now and 1100hrs and we've never a single problem".

That's what good maintenance is all about

[L.Adamson]

An interesting and current thread.

It's yes, no, & maybe....... as you read through them.

But somewhere along the line, some shops use .32 & Hartzell recommends .41

L.Adamson --- RV6A

http://forums.matronics.com/viewtopi...77b3e24b176267

[rvbuilder2002]

Originally Posted by L.Adamson

An interesting and current thread.

It's yes, no, & maybe....... as you read through them.

But somewhere along the line, some shops use .32 & Hartzell recommends .41

L.Adamson --- RV6A

http://forums.matronics.com/viewtopi...77b3e24b176267

Lee and John, the Hartzell engineering dept. guys I have worked with in the past, used .032 safety wire (not sure what size the documentation specifys; if any) so that is what I use. The .041 is much more difficult to install.

[noelf]

...folks put on a new CS prop on a Certified bird the other day. Once the prop bolts are snugged down (with the included roll pins installed) they torqued each nut to the proper value. Next they painted a small mark on each nut and the corresponding point on the prop hub flange. This became the reference position for the proper torque of that particular nut.

The final step was to back-off any nut that did not align the roll pin so that a length of safety wire could be installed in "pairs" with an adjacent nut. Once the safety wire was through the roll pin, they used a wrench to re-position the nut to the "reference mark" and proceeded to twist and secure the wire.

[cfiidon]

Rick,

Is that a Whirlwind prop? The bolts look the same as on my WW200RV. The manual said to safety wire them in pairs, but to do it IAW AC43.13 meant that the safety wire would rub against the aluminum and I didn't want that. I wired them serially (after looking at all the acceptable practices in AC43.13) , having the 0.32 safety wire thru the roll pin, around the bolt head and over the top. Not ideal, but they're not coming off.

Interesting, but for a bolt to back out, ALL of them would have to back out sequentially because of the clearance with the hub.

I have a four bladed Hartzell on my Bonanza, and there are NO safety wire provisions.... on a three bladed Hartzell I recently helped my brother install n his Bonanza, there is.

Go figure.

[cfiidon]

I found this Torque wrench adapter indispensable in getting to those bolts. My crows feet were not big enough and I didn't want to make an adapter, so I bought this:

http://www.motionpro.com/motorcycle/partno/08-0380

Pricey, but I'm sure I'll get lots of use out of it.

Don