Hi John,
Unfortunately you are correct; the ARAC committee was tasked on 11 April 2014 - up to that time it is still special conditions (what is not fly-by-wire in the airline and advanced corporate jets these days?).
The guidance that I saw was general and contained in AC 25.1329 (and in various other rules/guidance in Part 25). Strangely enough, EASA have seven references to fly-by-wire in AMC No.1 to CS 25.1329 as opposed to four in AC 25.1329.
Begs the question I asked before: what is being used for certification of FGSs? I have also just noticed the reference in AMC 25.1329 to manufacturers' FCOMs ("The normal procedures for use of the FGS should be documented in the AFM or FCOM, as appropriate. These procedures should be demonstrated during the type certification process.").
Why don't we split this subject off into another thread and see what views turn up? I would be interested in whether Bell are prepared to comment on their system for the Relentless.
Jim