999. Trespass on licensed or authorised aerodromes.

Any person who trespasses on any land which forms part of a licensed1 or authorised2 aerodrome is liable on summary conviction to a fine3, but no one is so liable unless it is proved that, at the material time, notices warning trespassers of their liability under this provision were posted so as to be readily seen and read by members of the public, in such positions on or near the boundary of the aerodrome as appear to the court to be proper