[...]
The outer surface, shown on Cambridge Bay Airport Zoning Plan No. E.1756 dated September 9, 1983, is an imaginary surface located at a common plane established at a constant elevation of 45 m above the assigned elevation of the airport reference point, except that where the common plane is less than 9 m above the surface of the ground, the imaginary surface is located at 9 m above the surface of the ground.
[...]