Air Canada

Air Canada would like to make the following comments: Under "Proposed AD Requirements" the first bullet proposes a one-time inspection of the No. 3 bearing packing at the next engine shop visit, but not later than 5500 cycles-in-service (CIS) since the last engine shop visit where the fan was removed from the core. However, the third bullet proposes removing certain rotating parts (LLPs) if they have operated more than 5500 CIS with the wrong packing configuration. Air Canada is concerned that not only is the third bullet inconsistent with the first but that it will be impossible to make a determination of Operating CIS with an incorrect packing configuration. The packings are un-serialized and un-tracked and with no additional guidance given (ie. timeframe when parts were mis-labeled and shipped) there will be no method of detemining how long an incorrect packing may have been installed. This is especially true for engines which have high times and cycles and have had multiple shop visits where the fan was removed from the core. Conversely, if an engine is inspected and found to have a correct packing, there is no guarantee that an incorrect packing had not been used on that engine between earlier shop visits. Thus the unsafe condition may neither be detected or rectified. We would encourage the FAA and GE to provide more instructions or guidance in the AD to ensure that LLPs are not needlessly replaced but also that an unsafe condition is rectified. Perhaps a growth check and/or hardness checks could be used to pass or fail LLPs where the operating CIS with the incorrect packing is unknown.