After his review of a Final Module Records Check; an Engine Inspector reports his concerns about Inspection not being involved with the approval process of sixteen helicoil removal and reinstallations on a Pratt-Whitney PW 4000 engine High Pressure Compressor (HPC) outer rear case that were later found inadequate. Lack of inspection of other reworked aircraft and engine parts were also noted.

Narrative

While reviewing final Module Records Check on PW-4000 module 2nd build from engine; I noticed one each item on the Non-Routine Write-Up's Job Card. Item one on page one of Non-Routine Write-ups states: Replace 16 each marked helicoils. [per] General Notes GN-1-0-8 / MM 72-35-09. Corrective Action states: Removed and replaced 16 each helicoils per MM 72-35-09. This work was approved by a Production Lead in the PW-4000 sub-assembly.I'm led to believe that work accomplished per [rework procedures] needs an Inspection Approval. No indication of Inspection Approval was accomplished on Non-Routine Write-up Job Card. I have filed several reports regarding my concern with this practice of not involving Inspection in the approval of rework being accomplished on aircraft parts. On one occasion recently the helical had a gap between the coils of the helical which may have resulted in a false indication of a properly torqued bolt. On another occasion when Inspection was called to do an approval; four each helical tangs were either not fully separated/removed from the end of the helical insert or were sitting loosely in the helical insert and were removed by an Inspector [in the] sub-assembly Inspection Department on graveyard shift during an Inspection sign-off.Granted the first example of the poor installation may have gone unnoticed and may have performed fine; however the loose tangs left inside the helical could have eventually resulted in FOD in the engine during testing. These two reasons should be sufficient to convince why we should have it mandatory to involve Inspection during the approval process of aircraft parts. I would also like to point out the lack of mention to nomenclature on the Non-Routine Write-up and can only assume the intended part involved pertains to the High Pressure Compressor (HPC) outer rear case.