1 fuselage: under normal circumstances, a pit or crack will be knocked out on the plane, and in severe cases, holes will be knocked out, but rarely.
2 windshield: this situation is more dangerous, because the cabin will be pressurized during the flight, and the internal pressure is greater than the external pressure. If the glass is damaged, it will cause the plane to lose density. In severe cases, the whole glass will break faster and lose its density, which makes it difficult for the aircraft to balance and has a great impact on its aerodynamic performance. On one occasion, another accident was that the windshield fell off and the plane was depressurized. The captain "sucked" out of the plane without wearing a seat belt! Windshield refers to several pieces of glass in the front cockpit. The glass in the engine room usually doesn't hit birds, at least I haven't seen it, it's just man-made damage.
Engine: As we all know, the front of an airplane engine is a rotating blade. If you are hit by a bird, you will definitely damage the blade. The engine is not only a rotating blade, but also a lot of it. The damage and shedding of the outermost layer will damage other blades and cause the whole engine to stop running (professionally called "air parking"). At the same time, when the blade is damaged, it will cause great vibration to the engine, damage the structure, and seriously cause the engine to fall off. Even the engine caught fire and exploded (which is rare). Cause of explosion: Because the wing above the engine is a fuel tank, debris leaks into the fuel tank, resulting in fuel leakage and fire, or the pilot failed to put out the fire on the damaged engine in time during the flight. The explosion caused by it is very common for planes to hit birds. Although there are bird repelling devices, they are generally birds such as sparrows, and there are few large birds, which generally only produce pits or cracks on the appearance of the plane, so the majority of passengers can rest assured to ride!