No Aircraft
Maintenance Airframe; Maintenance Powerplant
Confusion; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Chart Or Publication; Staffing; Procedure; Manuals; Human Factors
[PW-2000 Engine] Module Number XXXX-8 was sent to [Engine Tear-down] Core Shop for disassembly of engine modules per Engineering. There was no [variance] letter attached to deviate from standard practice of using the Engine Inspection procedures for inspection of modules or parts. The engine inspection procedures for the high pressure compressor assembly; diffuser module; intermediate module; rotor module and stator module all have; in the engine inspection procedures; a statement under General Inspection that states; that parts removed from module (physically separated) during the course of repair; must be inspected to the Serviceability Inspection Limits specified in the piece part of the engine inspection procedures. Since this is an engine [that has another Repair Contractor involved] and we have a contract to route piece [individual] parts to them; we; per Repair Contractor contract; to the best of my knowledge; are not allowed to route parts through our Inspection cleaning and repair cycles. Therefore; any parts that are separated need to be inspected per Piece Part Inspection; which this Module Number XXXX-8 engine core was not. The standard practice is for piece parts that are separated are Repair Contractor parts and are routed to them. Any past deviation to this practice was per attached variance letter to inspect parts visually only. This core; with its modules; does not have this variance letter and therefore; piece parts that were separated cannot be inspected to visual module level as it was inspected per Inspector Y.
Reporter stated his company overhauls different engines including PW-2000 and PW-4000s. Some of the PW-2000 engines come in with 12th stage seal problems that cause damage to the rotor; or have other specific problems involving a module that did not necessarily need to be completely overhauled. They needed a 'variance' letter from their company PW-2000 Engineering Department that would allow their Engine Shop to reassemble modules that had been separated; after specific repairs were made and a visual inspection had been accomplished on the exposed module's parts. With a variance letter; they would not have to further disassemble the separated modules and send the module's (individual) piece parts out to the other repair contractor; just because the Engine Shop had separated the some of the modules.Reporter stated their PW-2000 Engineers believed their Engine Shop mechanics and inspectors could; without any documentation; just bypass their own Engineering Engine Shop procedures. After he showed Engineering a 'variance' letter their PW 4000 Engineers had written for the exact same situations involving their PW-4000 Engine repairs; a 'new' variance letter was finally written and implemented for the PW-2000. He has noticed their PW-2000 Engineering staff are constantly rotated and don't have the same stability in staffing as their PW-4000 Engineers.
An Engine Shop Inspector reports about his efforts to get his company PW-2000 Engineering Department to issue a 'variance' letter. The variance was necessary to properly document that a deviation from their Engine Inspection procedures was approved by Engineering after PW-2000 engine modules were separated.