FWF Adel clamps AN3 safety wired or AN3A nylon nut

[ssturges]

I noted on the cabin heat scat tube mount Vans drawing calls out for a AN3 with a castle nut safety wired on the adel clamp. Should all FWF adel clamps be safety wired? I saw some hints that DARs could reject using nylon lock nuts? Is there a workman standard for this?

Thanks,

Steve

[Raymo]

Castellated nuts generally have cotter pins installed. No need in this application but, as a general rule, go with all metal (hot) lock nuts FWF.

[maniago]

Originally Posted by ssturges

I noted on the cabin heat scat tube mount Vans drawing calls out for a AN3 with a castle nut safety wired on the adel clamp. Should all FWF adel clamps be safety wired? I saw some hints that DARs could reject using nylon lock nuts? Is there a workman standard for this?

Thanks,

Steve

Basically, nylock nuts are frowned upon in the FWF area, so consider that your over arching guidance here....
Tho not specifically mentioned, but as a corrolary, worm clamps I safety wire as well (tho Ive never seen or heard of a worm clamp come loose in any application, aviation or otherwise) ......wire running thru the slot. I dont know if its a requirement, but seems like no harm good idea, and Ive seen others do it.

[RV7A Flyer]

Originally Posted by maniago

Basically, nylock nuts are frowned upon in the FWF area, so consider that your over arching guidance here....

As noted numerous times, somebody forgot to tell Lycoming that

[Bicyclops]

Originally Posted by maniago

Basically, nylock nuts are frowned upon in the FWF area, so consider that your over arching guidance here....
Tho not specifically mentioned, but as a corrolary, worm clamps I safety wire as well (tho Ive never seen or heard of a worm clamp come loose in any application, aviation or otherwise) ......wire running thru the slot. I dont know if its a requirement, but seems like no harm good idea, and Ive seen others do it.

I had the worm clamps on my exhaust pipe rear hangers come off several times until I started safety wiring them.

All my fwf nuts are all metal locknuts.

Ed Holyoke

[maniago]

Originally Posted by RV7A Flyer

As noted numerous times, somebody forgot to tell Lycoming that

Mmmm, yeah I know. I replaced the factory nylock nut holding one of my inj line clamps with a metal one. I think the key here is Lyco may have done all the temp tests in various areas and determined it ok in places, but they know where those places are and we dont.

For the average builder who isnt up to contemplating specific situations (much less do any testing) extrapolating the use of nylock nuts anywhere FWF just isnt a defensible argument.

Sticking with "frowned upon" is an nice way to people out of the statistics column. And off the DARs "what were you thinking?" list......

[RV7A Flyer]

Originally Posted by maniago

Mmmm, yeah I know. I replaced the factory nylock nut holding one of my inj line clamps with a metal one. I think the key here is Lyco may have done all the temp tests in various areas and determined it ok in places, but they know where those places are and we dont.

For the average builder who isnt up to contemplating specific situations (much less do any testing) extrapolating the use of nylock nuts anywhere FWF just isnt a defensible argument.

Sticking with "frowned upon" is an nice way to people out of the statistics column. And off the DARs "what were you thinking?" list......

Yeah, I just didn't want someone (newbie ) panicking thinking they had to go around and swap out all the Nylocks that Lycoming (or a Lyclone vendor) had installed when the engine was built. I used a lot of all-steel locknuts FWF myself, as well as the blue high-temp Adel clamps.

[rvbuilder2002]

Originally Posted by ssturges

I noted on the cabin heat scat tube mount Vans drawing calls out for a AN3 with a castle nut safety wired on the adel clamp. Should all FWF adel clamps be safety wired? I saw some hints that DARs could reject using nylon lock nuts? Is there a workman standard for this?

Thanks,

Steve

I think you have misinterpreted what the instruction is.
Where specifically are you talking about (Model, Section #)?

The only use of safety wire related to an adel clamp that I am aware of is to bridge the clamp with safety wire from both sides of a control cable to prevent the cable from ever sliding through the adel clamp.

[Charles in SC]

Another thing to think about is the type of cushion clamp you choose to use. In the FWF area I am using steel clamps instead of aluminum.

[ssturges]

Originally Posted by rvbuilder2002

I think you have misinterpreted what the instruction is.
Where specifically are you talking about (Model, Section #)?

The only use of safety wire related to an adel clamp that I am aware of is to bridge the clamp with safety wire from both sides of a control cable to prevent the cable from ever sliding through the adel clamp.

This is OP-54(exhaust system) page 4 Figure 2, the parts provided in the kit are an AN3-4 and an AN310-3 with the instructions to safety wire the scat tube clamp.

I find the FWF the safety weak point of the kit(RV9A IO320 in my case). A lot of builder improvisation is required on clearances, routing, and techniques. I see lots of places were someone could do something wrong the could compromise the safety of the airplane. Case in point almost every time a FWF image is posted on Vansairforce people point out errors.