When performing CFM56-7B SB 72-0515 REV 3 (J-hook inspection or HPC stator-to-rotor contact), it can be difficult to make a decision based on the things you see through the borescope. The SB is very large and needs to be read several times to understand the contents. To make the inspections easier, this SB is now simplified in this document, together with some example photo’s and clear explanations.
Link: SB 72-0515 J-hook inspection simplified
The CFM56-7B SB 72-0515 REV 3 ( J-hook inspection or HPC stator-to-rotor contact ) calls for an inspection which is very difficult to do, and even more difficult to judge after you find damage, to make the decision to remove the engine or not.
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Short video to show stage 3 segments movement because of worn VSV bushings: