sean_johnson16•2mo agoProlific Poster

Finally got a borescope inspection done in under 20 minutes

I've been chasing a compressor stall indication on a CFM56 for three days. Old me would've spent an hour jockeying the scope around and still missed spots. Today I used a different approach: started from the turbine end and worked forward instead of the usual way. Whole inspection took 18 minutes and I found the damaged blade on the first pass. Anybody else got a weird trick that just clicked one day?

3 comments

3 Comments

milaprice2mo ago

I read somewhere that GE actually recommends starting from the exhaust end on certain CFM builds because of how the airflow patterns affect blade positioning. Not sure if that's what you did but it lines up with what a buddy from the depot told me. He swears by flipping the scope approach on high bypass engines to catch lean damage on the HPT. Been meaning to try it myself on the next stall code I get.

clairem472mo ago

Borescoping from the cold section first would catch that rotor bow before it chews up the HPT blades though.

the_wren2mo ago

Flipping the scope approach" sounds clever in theory but I've seen that cause more blade rub reads than it catches. Have you actually gotten a lean damage hit that way, or is it still just a theory?