DERG, If you wish to selectively quote from
The Key Document Faa A.c. 33.63-1, then perhaps you should also give consideration to paragraph 2b. on the first page. ie.
2. Who does this AC apply to?
.....
b. This material is neither mandatory nor regulatory in nature and does not constitute a regulation. It describes acceptable means, but not the only means, for demonstrating compliance with the applicable regulations. We, the Federal Aviation Administration (FAA), will consider other methods of demonstrating compliance that an applicant may elect to present.
I should think that
TCDS NUMBER E00075EN is the FAA's position on the Trent 970/972 engine.
However , if it happens that you are on the FAA board, then please accept my apologies.