b.. the pilot must be able to navigate by reference to the ground and
c.. position fixes must be taken at least every 30 minutes.

Interesting. (Oz rules)

Does (b) mean that at any point in the flight, one must be able to
determine their position by reference to the ground visible at the time?
Or does this allow ded reckoning between visual fixes?

Given that radio navigation equipment is probably required and certainly
permitted when "over the top", do the position fixes required in (c)
need to be visual, or can they be VOR fixes?

Jose
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