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A mechanic reports the normal cleaning of pratt whitney low pressure compressor (lpc) spools was to use a baking soda blast with a 12/16 plastic media. But the ge CF6-80 lpc's calls for a plastic media of 20/40 mesh for cleaning the spools prior to being overhauled. The shop was continuing to use the 12/16 mesh without approval.
| Attributes | |
| ACN | 847032 |
| Time | |
| Date | 200903 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | No Aircraft |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Other Repair Shop |
| Component | |
| Aircraft Component | Compressor |
| Person 1 | |
| Function | Technician |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy |
Narrative:
My airline needed engine modules for their CF6-80's. The process we used to clean the low pressure compressor was with a baking soda blast. The booth could not handle that large of a part. Another shop was able to clean the compressor spool; but they were using plastic media of 12/16 mesh; which is good for pratt and whitney (engines); but the general electric manual calls for plastic media of 20/40 mesh.it is noted that pratt and whitney uses plastic media on titanium parts and the spool is made of titanium. We should stop using plastic media of 12/16 mesh and use 20/40; or get general electric approval for that cleaning method. The spools needed to be overhauled; but the process to clean was not good enough. The engine manual said we could use plastic media. It turns out to be the wrong type of media to be used.
Original NASA ASRS Text
Title: A Mechanic reports the normal cleaning of Pratt Whitney Low Pressure Compressor (LPC) Spools was to use a Baking Soda Blast with a 12/16 plastic media. But the GE CF6-80 LPC's calls for a plastic media of 20/40 mesh for cleaning the Spools prior to being overhauled. The Shop was continuing to use the 12/16 mesh without approval.
Narrative: My Airline needed Engine Modules for their CF6-80's. The process we used to clean the Low Pressure Compressor was with a Baking Soda Blast. The booth could not handle that large of a part. Another Shop was able to clean the Compressor Spool; but they were using plastic media of 12/16 mesh; which is good for Pratt and Whitney (engines); but the General Electric Manual calls for plastic media of 20/40 mesh.It is noted that Pratt and Whitney uses plastic media on titanium parts and the Spool is made of titanium. We should stop using plastic media of 12/16 mesh and use 20/40; or get General Electric approval for that cleaning method. The spools needed to be overhauled; but the process to clean was not good enough. The Engine Manual said we could use plastic media. It turns out to be the wrong type of media to be used.
Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.