The CL 415 was probably flying 90 - 100 kts at the time of impact and the aluminum skin on the leading edge of the wing isn’t very thick. At least it was the wing instead of the windshield. Even a small drone under 5 lbs can be a lethal missile at those speeds. The pilot of a manned aircraft usually can’t see a drone because of it’s small size but also because you are maneuvering the aircraft at low level just above the trees and looking for obstacles as well as your drop site. It would be helpful to have some sort of drone detection device on board a manned aircraft that receives the 2.4 GHz or 5.8 GHz band signals in close proximity. Even having a smartphone with an app like Drone Scanner would increase the safety of the manned aircraft.