CF6-80C2 Nacelle - Deviated Repairs from OEM SRM/CMM

[Aero_GUY]

Hi Coleagues,
I would like to know whether CF6-80C2 engine nacelle structure damages deviated from SRM, a minor repair approval from EASA Part 21J DOA can be issued or not.
I heard from a EASA Part 21J that CF6-80C2 nacelle structure cannot be approved under their approval. Suggested me to apply for a DER major approval and EASA bilaterally accepts the DER major approval.

 

[SWComposites]

Probably depends on the extent of "deviation" from the SRM, the location, repair type, etc, etc.

Have you contacted EASA?

 

[jaceb]

My suggestion is to contact directly nacelle manufacturer with this issue - probably it will be STE/MRAS in Baltimore in this specific case...

 

[WKTaylor]

H... Some parallel 'thoughts/comments' on the subject, based-on several years of field and depot maintenance experience of Nacelles.

Often SRM repairs are developed for expected/extraordinary deterioration, typical/expected external damage [IE: bird strikes, etc], engine failure/containment... or SRM-added 'special repairs' developed over many-years due to real-world service-damage experience.

However... the external world is full of surprises... be cautious about trying to 'make-a-fit' with existing SRM repairs for all damage. A 'neat-fit' of unique damage-to-one-or-more SRM repairs may not be possible... and heroic engineering analysis/repair may be required by a DER [or equivalent].

Certainly, the Nacelle OEM engineers will have the best understanding of the structure... hence may have insight into suitable/unique requirements. 'Creativity' of the repair engineer... in-bounds of the engineering is useful. OH and sometimes reparability is limited by extreme costs... replace being a less expensive/intensive/heroic option. OH... and the OEM has access to original tooling and assembly mechanics for every aspect/element of the assembly... or at-least 'should'.

Be Cautious... with composite/honeycomb nacelle structures... successful repair may be an illusion... since contours/fits/clearances are often tight and very critical... and easily messed-up.

Regards, Wil Taylor
o Trust - But Verify!
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[jaceb]

fully agree - Continental Airlines can say something about that....

 

[Aero_GUY]

Thanks for your comments.

SWComposites - I will be contacting them but wanted to see any reason before contacting them.

 

[SWComposites]

Harshene -
Way more info is needed.
What is your organization - airline, MRO, other?
Where exactly are you located?
Who has designed the subject repair?
Have you contacted the nacelle manufacturer for an approved repair?
A Part 21J DOA organization would need specific EASA authorization for a CF6 nacelle repair in order to approve your repair. Did the DOA that you contacted have that authorization?

 

[Aero_GUY]

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Hi SWComposites,
I am working with an MRO based in ASIA.
I also have previously worked with Part 21J.
Can you let me know what specific authorization is required for CF6 nacelle repairs. DO you mean CS-E privilieges.</sub>