The very fast spinning blades, the engine intake, the windshield, the tail rotor. Pretty much the entire vehicle is composed only of critical parts, because any

The very fast spinning blades, the engine intake, the windshield, the tail rotor. Pretty much the entire vehicle is composed only of critical parts, because any extra parts add weight and increase fuel costs. Helicopters, and especially their engines/blades, operate at high speeds as well.