Thank you for your reply Dutch One...
I was wondering of there was any OTHER case were the landing gear might have to be extended by gravity. As I wrote in my initial post, I fully understand the effects of having ADR 1 and/or 3 giving erroneous readings, or if they are switched off.
(btw, we donīt have BUSS installed on our A330, therefor in THIS case, unlike ADR 1+2+3 Fault, we never switch all 3 ADRs off, one will always remain on in order to benefit from stall warnings).
Anyway, once again, many thanks for your input!