What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Aircraft vs non-aircraft parts: when is it ok?

Steve Crewdog

Well Known Member
Patron
We all joke about getting supplies from the National Aircraft Parts Association (NAPA auto parts store), but while working on my avionics lately I've been using a mix of Adel clamps from Home Depot and ACS (you never have the right part at 9am on Saturday morning with the rest of the weekend scheduled and free for working on the plane, and I am planning on going back over and replacing the HD clamps with ones from ACS later.).

I'd never use a non-aircraft rated part in a critical area such as the engine compartment, but as I fought to secure an ACS Adel clamp in a difficult location I thought about the 1" HD clamp sitting on the bench that had far less resistance and would be far easier to use.


So what do you think? When, or would it ever be, ok to use an a non-aircraft vs aircraft rated part in an aircraft?
 
Last edited:
We all joke about getting supplies from the National Aircraft Parts Association (NAPA auto parts store), but while working on my avionics lately I've been using a mix of Adel clamps from Home Depot and ACS (you never have the right part at 9am on Saturday morning with the rest of the weekend scheduled and free for working on the plane.). I'd never use a non-aircraft rated part in a critical area such as the engine compartment, but as I fought to secure an ACS Adel clamp in a difficult location I thought about the 1" HD clamp sitting on the bench that had far less resistance and would be far easier to use.
So what do you think? When would it be ok to use an a non-aircraft vs aircraft rated part in an aircraft?

That decision is strictly up to you. If it is in question, then I suggest you not use that particular part.
I would further strongly suggest that you point out any "hardware store parts" to your inspector and let him/her make a decision.
 
While a lot of HD and ebay parts look like the equivalent, sometimes (not always) they are made of inferior materials, and can fail when exposed to vibration or heat or fire.

I find it's always useful to ask myself the question "what happens when this fails at the worst possible time?"

Here's an example where I used some components from a hardware store.

http://www.rv8.ch/heat-shield-home-made/

IMG_2701.jpg

So far it's holding up well.
 
I'd never use a non-aircraft rated part in a critical area such as the engine compartment, but as I fought to secure an ACS Adel clamp in a difficult location I thought about the 1" HD clamp sitting on the bench that had far less resistance and would be far easier to use.

Reminder to use the right clamp in the right place. "Far less resistance" probably means it is made of a weaker material. Refer to the "Everything you ever wanted to know but were afraid to ask" handy guide to make sure you are using an appropriately rated clamp in critical areas.

When using anything non-aviation intended, I always try to ask myself "If this fails, will it be an annoyance, ruin my day, or will it kill me". So you if are stacking zip ties together to hold your cup holder in just the right spot, that's probably ok. If you are using a stack of zip ties to hold the fuel line off the muffler, might want to reconsider that approach...
 
Cracked Rubber

I had a handful of never used Adel clamps from HD that sat in my hardware bins for 3 or 4 years. The rubber dried out and cracked on all of them within a couple of years. My .02.
 
We were in a Chipotle last evening kind of late and the chairs were stacked upside down on top of the tables. The metal legs of the chair were secured to the wooden seats with adel style clamps. I was tempted to look for the ms number. My next thought was, poor soul that put those together.
 
...and

I had a handful of never used Adel clamps from HD that sat in my hardware bins for 3 or 4 years. The rubber dried out and cracked on all of them within a couple of years. My .02.

For another data point, I have a box of misc Adel clamps that my Dad got from a rep 40 years ago...there are black and silicone red clamps as well as some of the solid white coating (unknown type). They all seem to be useable with no apparent cracking or splitting. I will say that the rubber is a bit harder when compared with a new Adel...
 
I used the aircraft grade stuff on anything I deemed critical... engine compartment, control surfaces, etc.

I used Ace Hardware stainless screws and bolts for things I didn't feel were critical... interior, panels, even wheelpants. In 300 hours of flying I think I've lost maybe 4 screws out of the wheel pants, mainly because I don't over tighten them.
 
Adel clamp tools

We were in a Chipotle last evening kind of late and the chairs were stacked upside down on top of the tables. The metal legs of the chair were secured to the wooden seats with adel style clamps. I was tempted to look for the ms number. My next thought was, poor soul that put those together.

I just bought a new tool that made it really quick and easy to install eight Adel (MS, not HD) clamps: SMA Tools Cushioned Clamp Installation Pliers
It seems quite a few companies distribute them, including Wicks on Amazon with one day free delivery.
https://www.amazon.com/dp/B076PSC658?psc=1&ref=ppx_yo2ov_dt_b_product_details

I ended up using the pliers and awl to close the clamp and align the two mounting holes. Then I inserted a screw, released the pliers and was able to move the clamp to position it so I could start the screw in a nutplate.

I also bought a Handee Clamp which looks like it will work with Adel clamps. I think the SMA tool will be quicker and I received it first so I haven't tried the Handee clamp with Adel clamps. I did use the Handee Clamp to start a nut in a hard to reach spot.
 
I've used non-aviation parts where there doesn't seem to be an aviation equivalent and I can't find a way to use aviation specific parts. I'm talking about foam padding and other non-critical components. Recently I was looking at fuel fittings from Jegs or Summit Racing, but went a different direction (literally?). Even then, I was paying attention to quality and they were still "AN" style fittings, 37* flares and all.

Non-aviation paint is pretty common.
 
It’s pretty much already been said, but the only time I would use non aviation specific is when its inconsequential and I’m sure I know any adverse impact.

Example: stainless Allen screws from ace hardware to mount the instrument panel. It’s normally a big no-no to lube nut plates but I dunk them in boelube to prevent any potential galling.

Downside- may loosen up over time, unknown alloy may rust over time. Definitely lower sheer strength.

Upside- they look cool.

In this application I’m comfortable going this way.

Adel clamps, not so much. When I install an adel clamp, I want whatever im routing to stay put and not chafe. No random pot metal or mystery insulation for clamps on my plane. No harbor freight zip ties either, unless they are just for temporary use.
 
non aviation material in ailerons

My Vans RV-6A kit included non-aviation grade common galv garden water pipe as counter-weights in the ailerons. Ailerons are kinda important so do you think it is OK if they are constructed from non-aircraft parts?
 
Water pipe weights and Non-cert plastics

The water pipe weights are just fine. They are just weights, with no structural element. I do recommend any steel items be well primed including the attaching holes and ends to prevent corrosion. The galvanized finish does help some, but drilling/cutting should be followed up with primer or paint. Most weights on certified birds are tungsten ($$) and in the "old days" were depleted Uranium, both of which have very high density/weight. As others have echoed, the hardware variety items with rubber/plastic coatings or parts often fail prematurely because of sub-standard materials. At my day job maintaining old heavy jets I see plenty of 40 plus year old Adels that are like new after years of hot/cold extremes.
 
SNIP

It’s normally a big no-no to lube nut plates but I dunk them in boelube to prevent any potential galling.

SNIP

??? I've been using toilet bowl wax to lube nut plates for over 20 years. If one doesn't use some sort of lube, normal AN screws will be all but impossible to screw in to many nut plates without galling or fretting the screw.
 
My Vans RV-6A kit included non-aviation grade common galv garden water pipe as counter-weights in the ailerons. Ailerons are kinda important so do you think it is OK if they are constructed from non-aircraft parts?

And don't forget the throttle, mixture and prop cables that come from Van’s with a label from Cablecraft that states “Not for Use on Aircraft!”

As the ancient knight said…. “Choose wisely……”. ;)
 
I laughed when I got my stall warning buzzer, directly from Vans. It still had its ‘Radio Shack’ label visible.
 
A popular transport category aircraft, the Dash 8. Early versions have the lavatory smoke detector sourced from the local hardware store. My home actually has a fancier models. Hey, it detects smoke and makes a loud noise. Doesn't need to have "airplane grade" stamped on it for an extra 1000% mark-up.
 
Back
Top