Welcome to the CPL Air Law question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
(1) AIP ENR 1.1 2.12.4 specifies a downwind report is required in CTA. Is there a similar requirement for when OCTA?
Some aerodromes do not require the carriage of radio, so a downwind call cannot be mandatory in all cases. Other than good airmanship and the general requirement in CAR 166C to make a broadcast wherever reasonably necessary to avoid a collision, is there any provision in the AIP that explicitly mentions a downwind broadcast when OCTA? Something similar to the 10NM broadcast when inbound (per AIP ENR 1.1 18.104.22.168).
(2) Where can I find a definition of "in the vicinity of the aerodrome"?