Nordlock vs Safety Wire

[Ironflight]

Originally Posted by Pilot8

What is Hartzell's position on nordocks?

There aren;t any washers involved in installing. Hartzell C/S prop - it doesn;t early have “bolts” exactly - more of a nut pinned on a threaded rod with a split pin. I don’t know where you’d put the Nordlock in this installation.

[bjdecker]

https://www.nord-lock.com/insights/v...-lock-washers/

Ok, I'm sold -- I'll put these on my brakes and replace that AN5H that I keep forgetting to safety wire (shout out to Vic)

I dunno tho, without the safety wire holes in my fingers, how will I ever remember that I finished putting something together?

[PerfTech]

Originally Posted by Ironflight

There aren;t any washers involved in installing. Hartzell C/S prop - it doesn;t early have “bolts” exactly - more of a nut pinned on a threaded rod with a split pin. I don’t know where you’d put the Nordlock in this installation.

...You have to un-pin the nuts and bolts from hub, then
reassemble them with the washers in place and re-pin.
I did a couple, seemed to work OK Thanks, Allan

[Andrew Anunson]

Originally Posted by erich weaver

Safety wiring my Whirlwind 200RV prop is a pain and I dread it. Is there any reason why Nordlock washers couldn’t be substituted?
Erich

Does your Whirlwind prop have an aluminum hub? If so, the Nordlock washers could work very well.

I don't think Nordlock washers would work at all with a one piece wood or composite prop since the hubs on these props can change with time and humidity (Isn't Catto and Hertzler now recommending belleville washer with their props?).

[BillL]

Originally Posted by Pilot8

What is Hartzell's position on nordocks?

Dunno, but their position on safety wire is "option", they don't recommend it, but say it is ok for the airframe manufacturer to add the safety wire.

[BobTurner]

Originally Posted by BillL

Dunno, but their position on safety wire is "option", they don't recommend it, but say it is ok for the airframe manufacturer to add the safety wire.

That’s correct. I know, because my DAR made me look it up. Their manual, wrt safety wire, says, ‘Follow airframe manufacturer’s guidance’.

[rvbuilder2002]

Originally Posted by BobTurner

That’s correct. I know, because my DAR made me look it up. Their manual, wrt safety wire, says, ‘Follow airframe manufacturer’s guidance’.

Maybe true, but I have worked with numerous Hartzell engineers doing propeller flight testing and I have never seen a single one of them take the option of not installing safety wire. Even when the prop was only to be installed for a couple of hours of testing.

[Ironflight]

Originally Posted by PerfTech

...You have to un-pin the nuts and bolts from hub, then
reassemble them with the washers in place and re-pin.
I did a couple, seemed to work OK Thanks, Allan

Yeah....but that is going to leave you a couple threads shorter on engagement on the prop flange bushings. I have no idea if that is OK or not - would want to see whomever designed the interface bless that configuration. There’s probably tons of margin - but the margin belongs to the designer, not the guy in the field!

[erich weaver]

The whirlwind prop also uses pinned nuts on studs, so the same concern regarding the degree of engagement would apply if Nordlocks were added. A call in to Whirlwind may be in my future.

Erich

[emsvitil]

I would think the little wedges of the washer would eventually screw up the flat matting surfaces.............