vertalop,
Thanks, this Type Certificate data sheet (TCDS) is the document. Note the Part II, Basis of Certification, section 2, reversions and exemptions (those are the Grandfather clauses). Specifically defined grandfathered sections are those most difficult to put in because they involve large changes, usually not economically feasible, like the crashworthiness shown, where the primary structure cannot take the crash loads, but the entire aircraft would have to be redesigned to meet the new rule. Also true of .571 Flaw Tolerance, for similar reasons, and the fuel system (the subject of lots of gnashing between RotorComparitor and me, unfortunately for other ppruners).
OK, with facts, buyers can know what they are buying. That is all we can ask!
Congratulations to EC for this achievement!
Here is the FAA's web site library for all the TCDS on file with them:
http://www.airweb.faa.gov/Regulatory...e?OpenFrameSet