Critical Parts May Have Been Improperly Repaired And Returned To Service

The FAA has issued a revised Special Airworthiness Information Bulletin (SAIB) to address concenrs about improper maintenance of CFM International CFM56-2, CFM56-3, CFM56-5A, CFM56-5B, CFM56-5C, and CFM56-7B turbofan engines.

The SAIB States that Propulsion Technology LLC of Miami, Florida (doing business as Propulsion Technologies International of Miami, Florida), might have improperly repaired and returned to service certain critical engine parts. This SAIB identifies the suspect parts by part number (P/N) and serial number (S/N) and recommends disposition of these parts.

A suspected unapproved parts (SUP) investigation regarding engine parts overhauled by Propulsion Technology LLC, repair station certificate number XZ4R084M, has revealed that repairs on CFM56 life-limited parts hardware did not meet the requirements of the CFM56 engine overhaul manual. Seal tooth plasma coating was inspected and determined to be, in some areas, thicker than the engine overhaul manual limits. The investigation also found seal tooth plasma coating overspray between the seal teeth, which was not permitted by the engine overhaul manual and potential missed cracks during the fluorescent-penetrant inspection.

After processing by Propulsion Technology LLC, the parts listed below may not conform to type design. We are developing inspections with CFM International to determine if the parts conform to type design, as well as developing repair procedures to restore nonconforming parts to type design.
Propulsion Technology LLC returned many of these parts to third-party suppliers and repair stations for subsequent installation. The potential non-airworthy condition of these parts was unknown to the third-party suppliers, repair stations, owners, and operators who, in some cases, returned these parts to service. We received the attached list that identifies by P/N and S/N, the suspect parts considered in the SUP investigation for the CFM56 engine models listed above.

The SUP investigation was completed and closed by the FAA in May 2008. A letter of correction was issued and this SAIB was initially released.

The Revision:

• Corrects seven part numbers, two serial numbers, and one description;
• Updates SUPs investigation status; and
• Updates the FAA contact information.

If parts identified in the SAIB list were never returned to service after processing by Propulsion Technology LLC, reinspect/ repair the parts per the most recent thermal spray repair documented in the engine shop manual (Example - 72-31-08 Repair 1 for CDP seal). Contact CFM International for further information on the type of inspections to perform. You may return to service any parts successfully completing reinspection/ repair for the remainder of their published lives.

If parts identified in the list were returned to service, remove the parts the next time the engine is inducted into a shop for engine maintenance. The reason we recommend removal of these parts is that the effect on part lives resulting from the weight of the extra coating combined with secondary flow and temperature variations and possible spallation, is unknown.

Contact CFM International for further information to determine part disposition.

FMI: SAIB with List