76As from the appointed day, the reference in subsection (1) of section 20 of the [1965 c. 16.] Airports Authority Act 1965 (which contains provisions with respect to telegraphic lines of the Postmaster General's) to a telegraphic line belonging to or used by the Postmaster General shall be construed as including a reference to such a line of the authority's, and the reference in subsection (3) of that section to the Postmaster General shall be construed as referring to the authority.