Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
NE-08-17
May 14, 2008
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin alerts you, operators,
repair stations, and principal maintenance inspectors of CFM
International CFM56-2, CFM56-3, CFM56-5A, CFM56-5C and CFM56-7B
turbofan engines that Propulsion Technologies International of Miami,
Florida, might have improperly repaired and returned to service certain
critical engine parts. This bulletin identifies the suspect parts by
part number (P/N) and serial number (SN) and recommends disposition of
these parts. At this time, this airworthiness concern isn’t an unsafe
condition that would warrant airworthiness directive action under Title
14 of the Code of Federal Regulations (14 CFR) part 39.
Background
A Suspected Unapproved Parts (SUP) investigation regarding engine parts
overhauled by Propulsion Technologies International repair station
certificate number XZ4R084M, has revealed that repairs on CFM56 Life
Limited Parts (LLP) 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 Technologies International (PTI), the
parts listed below might not conform to the type design. We are
developing inspections with CFM International to determine if the parts
conform to the type design as well as developing repair procedures to
restore nonconforming parts to type design.
PTI returned many of these parts to third-party suppliers and repair
stations. The potential unairworthiness condition of these parts were
unknown to owners and operators who, in some cases, returned these
parts back to service. We received the attached list that identifies by
P/N and SN, the suspect parts currently under investigation in this SUP
investigation for the CFM56 engines models listed above.
We are evaluating final corrective action plans that might include
mandatory withdrawing of the suspected parts from service. We expect to
complete the investigation by the fourth quarter of calendar year 2008
Recommendations
By issuing this Special Airworthiness Information Bulletin, we alert
all operators, repair stations, and their respective principal
maintenance inspector of critical engine parts that PTI might have
improperly repaired and returned those parts to service.
We recommend taking the following interim actions.
Operators and repair stations with parts identified on the attached
list that are not installed in engines should not install the parts at
this time, but should reinspect the parts per the applicable CFM56
engine overhaul manual. You should contact CFM International for
information on the type of inspections to be performed.
Operators with parts identified on the attached list that are currently
installed in engines should remove parts the next time an engine is
inducted into a shop for engine maintenance.
You should contact CFM International for further information to determine disposition.
For Further Information Contact
Stephen Sheely, Aerospace Engineer, FAA Engine and Propeller
Directorate, Engine Certification Office, ANE-141, 12 New England
Executive Park, Burlington, MA 01803; phone: (781) 238-7750; fax: (781)
238-7199; e-mail: stephen.k.sheely@faa.gov.