Fan fail . . . twice

[Mike Buettgenbach]

Here's a strange thing. Not exactly a problem . . . yet.

This is my second '12. First one -- no fan problems. There are two fans for the "avionics"; one intake on the pilot side above the knees and one exhaust on the passenger side above the knees.
This aircraft has about 100 hours. Strange sound the other day -- sounded like the fan. Sure enough, the fan lost a blade.
Ordered a replacement from the aviation department of Amazon.
Waiting on the new fan, found a near replacement to use as a temp solution and wired / installed this one. Tested okay.
Two flights - strange sound. Yep, this one lost a blade also [and the failed blade ended up in the exact place as the original failed blade]

Have now installed the proper replacement fan. All is good after one flight. [I bought 2 just-in-case]

Summary:
Having two failures close together (and a kind of fail that I consider unusual) puzzled me, so I thought I pose this to the group.
They are pretty basic fans and inexpensive, but losing a blade just strikes me as an unusual fail in this situation

Anybody experienced fan fails like this?
Thanks

 

[bobg56]

I would think some sort of FOD is striking the fan causing blade failure, could there be something that is getting sucked in that is close to the fan? a long tie wrap tail?

 

[rcarsey]

I ended up replacing mine early on to ones with ball bearings instead of sleeves.

 

[blaplante]

Hmmm. Plane outside in a hot location much? Maybe getting hot enough that the fan blades warp.
Try getting one from a real electronics supply house i.e. mouser.com or digikey.com