CS 22.773 Cockpit view
CAA ORS9 Decision No. 1
Each cockpit must be free from glare and reflections that could interfere with the pilot’s vision, and designed so that:
(a) the pilot’s vision is sufficiently extensive, clear and undistorted for safe operation; and
(b) each pilot is protected from the elements. Rain and icing may not unduly impair his view along the flight path in normal flight and during landing.