Mark

767-200 with 80A engines.

"Bleed Off" light on during flight. Bleed air test box  showed "Fan Air Valve Temp Sensor" fault.

Compared left and right engines.....
  
     
  
Sensor located behind "D" panel in pylon, just below PRSOV.
  
     
     
  
Removed.....
  
     
  
Replacement with resistance measurement.
  
     
     
  
What seems to be missing on removed unit?
  
     
  
The whole temp probe is gone. Sheared right off at the base. Where did it end up?

We looked down with a borescope. It wasn't laying on heat exchanger. It must of been blown up and down-stream..... possibly setting on primary heat exchanger in left pack bay????