Complex sentence: The curved roof edges provide a finished appearance for airplane passengers taking off/landing at the nearby main airport across the lake in addition to its airplane-wing shape helping to wind-scour snow from the roof to avoid ice and water damage.
Split into simpler sentences: The curved roof edges provide a finished appearance for airplane passengers taking off/landing at the nearby main airport across the lake. This shape mimics an airplane wing to help the wind scour snow from the roof to avoid ice and water damage.