What is this part of?

deyoung

deyoung

Line Up and Wait
Joined
Nov 13, 2014
Messages
508
Location
Tucson, AZ
Display Name
Display name:
Chris
Any ideas on what this might be part of? I found it on the floor of my hangar today... looks like the end of a 1/8" diameter pin from something. It may not be clear from the pictures, but one end is clearly broken off. I didn't find anything on the airplane that looks like it might have come from, but if it did come from my airplane, it's a PA-28-235.

Thanks!

https://chd.smugmug.com/Mystery-Part/
 
From the hangar structure, door, or opening mechanism?
 
Structure, possibly; door or opening mechanism, unlikely, since the door is purely mechanical, I push it sideways on rollers like a train car door. It has no parts this small. :)
 
It looks like the fractured shaft of a standard rivet that wasn't ever bucked.
 
I'm guessing it's an electric motor or alternator brush. One side is concave rubbing against the armature and the other side is a recessed flat cup to hold the tension spring.

Just as likely a holding or locking shaft that broke, which was pressed forward with a spring.
 
Last edited:
It's a stretch but it looks kind of like a semi-hollow brake lining rivet shank with the head drilled off before being set.

Nauga,
and a shot in the dark
 
It doesn't appear to be broken. It looks like it's been drilled. But no expansion like a rivet and no marks like it had been pressed in. Is this a private hangar? Maybe it clung to a tire and came in from outside. Or maybe a buddy dropped it to make you go nuts looking for where it came from.
 
3393RP said:
It looks like the fractured shaft of a standard rivet that wasn't ever bucked.
Click to expand...
The "factory end" has a rim and a recessed area - not flat like a typical rivet

Stewartb said:
It doesn't appear to be broken. It looks like it's been drilled. But no expansion like a rivet and no marks like it had been pressed in.
Click to expand...
The broken end was inside something - shiny ring from being pulled out of something - but, as you note, not a lot of expansion. Perhaps that's why it got drilled out.
 
Yeah, my guess was a rivet also, but I'm not missing any that I can see. It certainly might have come in from outside; my hangar is not exactly well sealed either.
 
Looks like a big rivet that was drilled out.
 
Is the roof of the hanger aluminum? It might be from there.

That appears to be a pressed in stop pin.

A mechanic removed it by drilling it from the back side. If it is from your plane, it has been riding quietly for some time, since your mechanic did the procedure to remove it, or, as someone has already theorized, it is from some other plane, and stuck in the tread of your tire and came loose after arriving in the hanger.

Over the years, I have picked up an amazing number of small pieces of metal from taxi ways, some clearly used, as yous is, others, brand new. The most valuable was from the touchdown area of the runway, a Cessna fixed gear jack adapter. It was as new, only a couple of dings in the paint, no rust, and the part number sticker was not even dirty. At that time we did not have a mechanic on the field, so no idea who might own it. No response from a note on the bulletin board.
 
deyoung said:
Any ideas on what this might be part of? I found it on the floor of my hangar today... looks like the end of a 1/8" diameter pin from something. It may not be clear from the pictures, but one end is clearly broken off. I didn't find anything on the airplane that looks like it might have come from, but if it did come from my airplane, it's a PA-28-235.

Thanks!

https://chd.smugmug.com/Mystery-Part/
Click to expand...
Looks to me like a structural blind rivet (type of pop rivet). Place it on it's end with the fractured end up and use a small 1/16" round flat end punch in the center and see if you can drive the center of the shaft downward. If a center shaft separates from the outside shank you will know for sure it is a blind rivet.

I would also try to pick it up with a magnet to determine if it is ferrous. Given that it is 1/8" in diameter it is a common aircraft rivet size. Has this airplane ever had any structural damage or any structure repairs? If it was my airplane I would be interested enough to go back through the airframe log book and review the repair history. And then visually inspect those areas.

Not easy to tell from the pictures but it does not look to me to have been drilled out as an A&P would remove it, more like a shear failure with possibly some fatigue signs from the wiping action on the surface of the failure. Do you see any signs of metal cracking or where the metal appears to have been pulled apart on one side of the end and the opposite side of the same end scuffed?
 
Last edited:
deyoung said:
Structure, possibly; door or opening mechanism, unlikely, since the door is purely mechanical, I push it sideways on rollers like a train car door. It has no parts this small. :)
Click to expand...
Doubtful they would have used an aluminum rivet in a hangar door.
 
It doesn't look like any pulled rivet I ever used. It doesn't look like any drilled-out rivet, including a brake rivet, which are brass in light airplanes. It's not part of any alternator brush. Not a Hi-Lok or Huck Bolt. Might be something left laying in the flap bay of an airliner. Fell out on the runway or taxiway and got picked up by a tire.
 
Let'sgoflying! said:
Your left wing is going to fall off, next flight.
Click to expand...

I doubt it. I found it over on the right side.

Briar Rabbit said:
I would also try to pick it up with a magnet to determine if it is ferrous.
Click to expand...
Will do, but I'm 90%+ certain it's aluminum.

Has this airplane ever had any structural damage or any structure repairs?
Click to expand...
No, not to my knowledge and not that's indicated in the logs. Visual inspection doesn't show any missing rivets or anything else where it looks like it might have come from. I'm suspecting it came from somewhere external, but just trying to be thorough.
Not easy to tell from the pictures but it does not look to me to have been drilled out as an A&P would remove it, more like a shear failure with possibly some fatigue signs from the wiping action on the surface of the failure. Do you see any signs of metal cracking or where the metal appears to have been pulled apart on one side of the end and the opposite side of the same end scuffed?
Click to expand...

I'll try to take some better pictures with a real macro lens; the first pass was just from a phone camera, so not so good. It does look to me like it might have been drilled out, now that I look for that, though I can't be sure. No signs of cracking or anything that looks like pulling stress.

I don't have my good lens handy but will try to add better pictures shortly.
Thanks!
 
There's a fine line between "a part" and "debris". My guess is this falls into the latter category.
 
yeah, sorry...I've got nuthin..... but I can sure see how that would make you take a serious look for a hole!

Could it have been outside and blown in under the door by a leaf blower?
 
It's the unbroken end with the recessed inside pin, or whatever, that makes this look weird. Another WAG, how about the end piece sleeve and pin from a hinge, somehow sheared off together?
 
Maybe someone's jacking with ya?
Some of the guys used to put a pile of pencil shavings under the wings at some of our Bellanca fly-ins.
 
On the F-16, there is an orange disc visible through a small plexiglass window. The disc is the hydrazine indicator. Hydrazine is the chemical kept in a tank and released in case of emergency which powers the flight controls and is extremely toxic. If there is any leak, the orange disc will turn black. To mess with new guys learning to perform engine runs, we used to remove the disk, tape it over with black electrical tape, get some ammonia from the cleaning cabinet and drip it on the concrete floor below the inspection panel. Then we'd tell the new guy to hurry up and do his walk around and watch what happens.

Yeah, we got bored a lot.
 
Years ago there was a grizzled North Central Airlines pilot in our EAA Chapter that thought it great sport to roll small screws etc down the aisle when flying DC-3s
 
You must log in or register to reply here.
Back
Top