Commercial Fixed Wing
Maintenance Powerplant; Maintenance Airframe
Maintenance Technician 1
Training / Qualification
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Aircraft Aircraft Damaged; General Work Refused
Aircraft; Company Policy; Human Factors; Procedure
While servicing the engine in question; corrosion was discovered on the mid shaft. The proper documentation was made by an inspector. The mid shaft was given the final sign off as O.K. to install by a different inspector. After installation the corrosion write up was found and the intent was to repair while installed in the engine fan case/fan frame. Repair was started in accordance with Engine Service Manual.Task was followed until where it states that after removing material with scotchbrite to a level beyond 0.002 inch to 'blend to a maximum depth of 0.0035 inch to remove corrosion' and if this must go deeper than 0.0035 inch to [do another task] and then 'Shotpeen the blended areas.'Seeing that if more material was to be removed; and it needed to as corrosion pitting was still present; I brought it to my lead and showed him that it may need to be shotpeened. Shotpeening is not available at [this facility] so the mid shaft would have to be removed and sent for repair. This was brought to the attention of a foreman. There was agreement to sand it using sand paper further to remove more but not all corrosion; not use NDT to measure the ending thickness of the mid shaft; leave the mid shaft installed; paint/refinish it to cover the remaining corrosion and log it as repaired. Painting has been [completed; however] the original corrosion repair write up has not been signed off as repaired by either mechanic or inspector. Many certified mechanics have refused to sign it off as repaired due to the unapproved methods.
Reporter mentioned that the engine in question was still in the shop and is being re-assembled without the corrosion damage to the mid shaft being addressed as called out in the maintenance procedure.
Maintenance Technician reported compressor shaft corrosion was not addressed per Engine Service Manual specifications.