Mystery Part….on top of wing…..

[takair]

Almost need a forum for mystery parts people find.  I enjoy the challenge except when it’s my plane.  Got back from a flight yesterday, put the plane in the hangar, walking around the plane and I find a ball bearing stuck to the wing at about half span, just forward of the flap.  Had a little oil or grease making it just barely sticky.  
 

I can’t figure out where it might have come from. Can’t see anything in the hangar, hard to believe it would have come out of the cowl and found its way there….  My leading candidate is FOD from the taxiway or runway, but even that seems odd.  Any ideas?

 

 

[takair]

16 minutes ago, bluehighwayflyer said:

That’s a weird one.  Any chance you have an electrically-powered bifold door in your hangar?  I do.  Otherwise, FOD.  

No, port a port with sliding doors…although I will take a closer look for something like the door track…

[takair]

2 hours ago, bluehighwayflyer said:

Lead shot?  No.  Scratch that.  Too perfectly round, I think.  

Looks very much like it is out of a bearing…..just can’t figure out where it came from and how it got up there….crazy…

[N201MKTurbo]

The porta port sliding doors have upper support wheels that could have balls like that.

[takair]

1 hour ago, N201MKTurbo said:

The porta port sliding doors have upper support wheels that could have balls like that.

Will check that out….

[RLCarter]

I found very similar ball bearing under my aircraft on this floor…. Over the next few weeks I found several others…. Seems a caster was coming apart on my creeper…… being on top of the wing makes it really odd, I would definitely look at the hangar door

[takair]

1 hour ago, RLCarter said:

I found very similar ball bearing under my aircraft on this floor…. Over the next few weeks I found several others…. Seems a caster was coming apart on my creeper…… being on top of the wing makes it really odd, I would definitely look at the hangar door

I did have the castor come apart in my creeper not long ago!!!  I did also blow out the hangar not long ago with a leaf blower!!!  Think we might be on to a strong possibility. That said, it would have managed to stay there for a few flights if that was the scenario. Although, based on the way dust manages to stay on the wing under the boundary layer, it’s not far fetched.